Old Delphi Forum Cockpit Deck notes
- Category: Hull and Deck
- Published: Monday, 14 July 2014 05:21
- Written by Super User
- Hits: 36069
ON REPLACING THE COCKPIT DECK WITH PLASTEAK:
I've been told by a couple of folks (including my surveyor when I bought the Marinette) that the cockpit decks are quite susceptible to rot; Marinette covered the plywood with a vinyl that neatly traps moisture. Looks terrific but rots over time. I ran across a fake teak product called Plasteak at the boat show. It comes in 6" tongue and groove (perhaps other sizes, too). Just replaced the teak bowsprit with this stuff. Got samples & ended up ordering enough 1 x 6 tongue & groove to do the deck, but I will leave off the saw cuts that give the appearance of narrow planks. Ordered it in sand color and plan on running a bead of silicone in each groove. I will screw the boards on from underneath with short screws. Also I ordered 1/4" sheets for the side panels in the cockpit. I liked the sand colored product but think it is overpriced (like everything else for boats) The side panels are actually cheaper than marine plywood by the time you factor in the vinyl & glue.
Plasteak Company has given very slow service. I have been waiting about a month for my order. & I got first confirmation on availability last week after my 5th phone call. Plasteak tells me their supplier is the problem.
I too need to replace a couple pieces of deck plywood due to rot, and the side panels are gone as well. I planned to use the original Nautolex, but have had difficulty in finding a good source for it.
Have you considered replacing the wooden deck structure with something like Trex or Plasteak? They won't rot and you won’t have the hassle of covering the wood with Nautolex.
I am in the process of using Plasteak tongue and groove 1x6s. I cut a few boards to length today & decided I need additional support, probably every 12 inches. The Plasteak is very limp. Also it took over a month to fill my order & it came in an off shade compared to the sample. I hope it’s worth all the hassle. Also it was a little expensive, I got 3 sheets of 1/4" seaboard for the sidewalls & enough 1x6s to do a 28" (8' x 10') & it was around $1,100.00
Plasteak folks have a booth at various boat shows where is I learned about them and wound up ordering a few pieces of tongue & groove stock to replace my teak bow pulpit. After nearly 4 months of saltwater service and lots of sun, the Plasteak does not show any wear. When I have to replace my back deck I will use this stuff even though it's pricey. I will never put down Nautolex again because it traps moisture and encourages rot.
Here's the address:
3563 Copley Rd.
PO Box 4390
Akron OH 44321
Plasteak is so limp a 10 foot 1"x 6" could easily be formed into a circle by hand. When warm, if held in the middle it droops more than 4 feet at each end. Had to support at least every 12" & decided to go every 6" near the helm areas. Used over 200 SS screws from the bottom up. It looks great. Still have to make new floor hatches (no small task) but so far so good. Its not slippery, but I have not gotten it wet. I used a sand color very similar to original Nautolex used on side walls. It stays fairly cool in direct sun & won't blind you if you look at it without sunglasses. Dirt shows readily but is easily removed with Softscrub type cleanser.
That flexibility may by why Plasteak folks recommended a thin recycled plastic sheet under the tongue & groove boards.
Replacing the cockpit deck with plywood covered with Nautolex:
On those cockpit side panels, by 1987-88, they used aluminum. I had the aft deck replaced on my 1989 28' Fisherman when the wood had turned to mush. For some reason Marinette used particleboard instead of marine grade plywood. This was a real job! I had a boat repair place do it for me. They had to take all of the cockpit walls off as well as the trim and bench seat. Special size plywood was ordered from Michigan, as standard 4x8 sheets wouldn't fit right (too many pieces). I believe they used two sheets of a bigger size. The wood was also encapsulated w/ the West System and new vinyl was applied. There were a zillion screws and allot of man-hours involved as well as a nice price tag. It does look beautiful when done. Perhaps a 32 Sedan would be easier but when it comes to boats, nothing is easier!
The plywood width is 5/8 inch for the 28 ft express not 1/2 or 3/4s. Seal with Minwax wood hardener before the apply west system, or covering with Nautolex vinyl. It will last 20 years. Ours was done in 1980, and needs only some of it redone (a hatch).
In the process of doing my 73 28 express. I special ordered 5/8 inch AC plywood and had it pressure treated. (Not recommended: the chemicals can attack aluminum.) The length required is 10' for the 28. The normal 4' width per sheet will do. What I'm doing is to piece it together just underneath the helm seat and the portside seat. This will enable me to do it with 8' length sheets instead of 10. I will cover the seam with a thin piece of stainless steel hatch trim. After much consideration, I decided to do it this way. I plan to put a thin rubber vibration absorbent strip on each support under the plywood to limit "buzzing" from vibration. I wish for Nautolex in "plank" of some other color besides white, but the manufacturer says it's not made. I considered using teak, too, until I found out that it would cost 3500 dollars. Too bad it would have made the classy old gal even classier.
I recently redecked my 28 single engine. I used a thick fiberglass resin coating on the 5/8ths marine plywood, and screwed them in from below with stainless screws backed with 3/4 dia washers. As long as the screws are snug, it won’t rattle. No caulk or rubber pads were needed. Access is tight, but once you're below its relatively spacious. You can’t really move the hatch without cutting away supports, but I suppose its possible. Any competent welder can frame a new hatch under the seats. That would make access too easy!
When my boat was surveyed, the surveyor told me that rotting cockpit wood decking was common on Marinettes. He said the Nautolex traps moisture, shortening the life of the wood deck, so make certain the wood is sound before applying a new vinyl covering. Another option is to use a simulated wood product like Trex or Plasteak. The deck will last forever. I replaced it 9 years earlier with marine plywood and the white striped Nautolex as original. A nightmare to keep clean.
I did my boat in the original materials: 5/8 marine plywood with the Nautolex glued over it. I cut out the deck pieces and dry fit them into the cockpit then I coated every piece of plywood with clear epoxy before I glued the Nautolex on. Do yourself a favor and remove the original pieces as if you are going to use them over, this way they will make more accurate patterns for cutting the new panels. It will require crawling into the bilge to remove the screws from below but you may as well get used to that. Get all the cutting done--the cockpit drains, hatch cutouts, new hatch etc.--before you throw anything away. I wouldn't want to have to do this job without patterns, not too many straight lines. I had to build a new hatch frame and I use treated lumber, the old one rotted. I used 3M 4200 instead of 5200 to bed in the new panels (5200 sets up too hard). I simply caulked in the new panels to the insides of the cockpit and did not reuse the aluminum inside molding, nor did I reuse the polished trim around the hatch or the piano hinge on the hatch because in taking the job apart it was apparent that these screws, (about 50 of them) were causing most of the rot. It's been 4 years now and it's solid as a rock. I think the hardest part of the job is covering the new panels so you get a nice smooth job and a pattern match. Could use a little help when you get to that part. You will need an electric stapler and SS or monel staples. Don't cheat on the plywood because of the price, the marine grade is easier to work with and you will only want to do this once.
You can buy Adhesive #88 for Nautolex at Mikes Marine Supply either online or at their locations in St. Clair Shores or Algonac. I just finished rebuilding my aft deck last night. I bought blue Nautolex and Adhesive at Mike's (good prices). The unfortunate thing about the aft deck is that I rebuilt it last year but used Pressure Treated plywood without knowing that Copper Chromate is used as the preservative. I guess I chalk that one up for 1st year experience with an aluminum boat. I must say I'm getting better with each deck made. Possibly I ought to make a template and offer to sell replacement decks.
But if you are just careful and look how the pieces are cut, use marine plywood and Nautolex you will just fine. Try to get the old pieces out without breaking them apart. If you do not think you can use shipping paper and make a pattern. Lay the pieces back in place before and after you put the Nautolex down. I probably got close to 90% of the screws back in from underneath. The only ones I could not get back in were the ones back under the tanks. It is a lot of work but it sure looks great. We did all the cutting and gluing the Nautolex down on the boards in our garage then took them to the boat.
I also did my new deck with Nautolex. My boat was sitting just outside my shop and I too used the old deck for a pattern. I can imagine your trying to fit it with the boat off site! I crab about the Nautolex being hard to clean but it sure looks beautiful
What do you recommend for cleaning Nautolex? I use Krazy Klean.
I went through a marine plywood/Nautolex deck replacement about 5 years ago. The stains just keep accumulating and it is starting to look dingy. For a couple years after it was finished it looked great but everything seems to mark it.
ON REPLACING THE COCKPIT DECK WITH DURABEK AND OTHER TRUCK BED LINER MATERIALS:
Durabek is a specially formulated polyurethane slip-resistant truck bed liner, marine deck and safety coating which comes in many colors. It is durable and user-friendly floor paint and coating that offers excellent slip and fall protection while at the same time protecting the surface from damage.
The specially treated rubber granules [which create the grit] are made from recycled tires. Durabak™ non-skid protective coating bonds to wood, metal, concrete, painted surfaces and will even bond to itself, making it easily repairable if necessary. Durabak™ is waterproof, resilient and UV resistant.
Have you thought about covering the surface with a material such as Rhino liner (white color), the stuff that one would use to cover the bed of a pickup truck)? Did you insulate the engine compartment hatches to dampen heat and noise transfer?
ON KEEPING RAINWATER OUT OF THE COCKPIT:
The Marinette rain gutters in the back, just above the air scoops, tend to flood the cockpit area--water roars out of them and onto the cockpit floor. Knowing the proclivity of the cockpit floor to rot out, we had an awning made that covers the cockpit, but these dumb rain gutters were still pouring water onto the cockpit floor. My solution was to silicone shut the aft ends of the rain gutters, then drill a bunch of 1/4 " holes in the bottom near the ends to allow the water to run down onto the deck instead. Worked slick--and I did it during the rainstorm!
Rainwater falling on the cockpit floor was leaking into the bilge on my 32 Sedan, soaking what was stored down there and overworking my bilge pump. I went on the warpath to correct this nonsense, and the fix has worked surprisingly well. To wit:
1. Prevent rain from falling on the cockpit with an awning (which also does a great job of keeping the sun out, especially with a sedan).
2. Modify your rain gutters. These gutters run along the side below the salon windows (as part of the side air scoops. They act like a molding at the top of the scoops.)Plug the gutters at the rear with silicone then drill a few 1/4 inch holes in the bottom nearby. Water now falls harmlessly on the walkway.
3. Perimeter seal the cockpit floor. Remove the sliding door lower track and seal the ends of the flooring to prevent water going under. Let the sealant cure overnight then put the track back down with more sealant, sealing each screw as well. Remove the aluminum strips (3) that go around the sides and rear. Seal here as well with silicone, let it cure overnight, then put the aluminum strips back. This is a tedious chore; drilling a pilot hole for each # 6 SS flathead screw, dipping the screws in sealer, etc.
4. Raising the cockpit hatch worked really slick. Water on the cockpit deck will simply flow into the bilge via the hatch opening, so I raised the frame around the opening with a series of aluminum strips, 1/8 inch thick by 2 inches wide. These strips are sealed and screwed to the floor with the hatch attached to them. (I thought that extra 1/8 inch of height would be a tripping problem, but one barely notices it.) This minor little ‘dam’ keeps the water out of the bilge.
5. Finally, the seams in the pieces of covered plywood that make up the flooring got a serious caulking.
MISCELLANEOUS IDEAS AND TIPS:
Putting screws into the plywood is OK, but you should drill oversized holes into the plywood, fill with epoxy and then drill the pilot holes into the epoxy. This prevents moisture from wicking into the plywood and hence prevents rotting.
Starboard is at least as expensive as Plasteak, which I used to replace the teak swim platform. Five or six years later it still looks as good as new and is super easy to clean when I get around to cleaning it. If I had to replace the cockpit deck, that's what I'd use and it looks as if the Nautolex is finally giving out after many years.
I ran across a product called MarineDeck 2000 manufactured in Holland by a company named Stazo. It is made of ground cork in a polyether-polyurethane binder. It looks fantastic. It is supposed to be pretty impervious to high heels, ouls and greases and fish entrails. It is a snap to install by anyone with decent carpentry skill. Materials only are $35 per sq foot, double that for installed. I'm going to put a latex deck covering on the cockpit this year so I can recover from the restoration and maybe even get waterborne this summer. However, when the deck needs to be replaced (a couple of years) this is my leading contender.
Is it slippery? I worry that somebody clumsy (ah-hem) might fall on their 'stern' if it gets wet.
I don't walk on the bow pulpit much as you would suspect, but on the few times I've practiced ballet moves there, it didn't seem especially slippery. It's worth checking, though.
There are those who want to keep their boat as original as possible. My boat is a fishing boat first and a Marinette second. I did things like rod holders and Plasteak floor. I am more interested in ease of upkeep and ease of fishing.
If you ask Marinette owners, they may say wood is easier on the feet. It may dampen the noise of the engines an may make the ride softer for those standing on it. But in the quest for the best boat at the best price cost has to come in at some point.
Encasing the plywood in epoxy will work well, but you need to take additional measures where screws go into the plywood. Any place a screw or bolt goes into or through the wood needs to be drilled out to a minimum of 2 times the outside diameter of the screw. Fill the oversize hole completely with epoxy or epoxy mixed with filler. Drill the correct size pilot or clearance hole (centered in the epoxy filled oversize hole) once the epoxy has fully cured. This method prevents water from entering the wood.
I spent well over 300.00 in materials and a lot of time on the project. I did epoxy all the wood before covering it and used monel staples so it would have half a chance of lasting.
If there is wood beneath your "waterproof" cockpit material, be careful. If a small amount of water works its way under the waterproof cover, it'll have a heck of a time migrating back out so the wood cockpit floor will rot fairly quickly. Even Nautolex creates this condition and sets up deck rot. I redid my cockpit deck 6 years ago with 5/8 “ marine plywood, coated with epoxy and covered with the original pattern Nautolex. I like the original look and I am sure it will go another 10 years. I think the flaw in the factory job was that they did not coat the plywood and they put too many screws in with no bedding. I also question if true marine grade plywood was used. The big thing to remember is that there is only 5/8 “to work with from the top of the cockpit deck framing to the bottom of the door sill, this limits your options.
We have a lot of commercial workboats and crabbers on the water down here, the Rhino hide would probably look good on them and they would save a cool $100.00.
As you will discover when crawling under the sole / deck and taking out all those damn little screws, it HURTS! (Get some thick carpet remnants 2' x 7' you can place on the inside over those hull sanctions). One must lay on their back, reach overhead (with a screwdriver bit on drill) and light. One must be flexible so a hot shower/stretching prior is advised. (Go ahead, laugh now, he who laughs first...) If you've gotta replace the deck, and your going to re-do the engine anyway, pull the decks prior to the engine. The engine is easier to pull after you remove the exhaust manifolds, intake and heads. With the deck out and some carpet under your butt, it's easy to work abound the motor. After cutting your new decks, reuse the undestroyed original deck sections as a working floor in the boat. (You don’t want to have an engine hoist on the new decks anymore than necessary). If you’re going to pull the deck, pull the sides and aft skirts (rail to floor). Be sure to SAVE everything so they can be used as a template for the new. The deck on our 28 was made from the better part of 2 sheets of 4'x 10' marine plywood 5/8 “thick. The seam between the two sheets runs down the centerline of the deck/ boat.
After crawling under and getting 99% of the screws, I cut across my deck using a circ saw and wood chisel on one of the supports about 2 feet back from the companionway door. (Set saw so as to cut wood, not support), Chisel out remaining distance (3-4 inches) near side where circ saw can't travel. The trick (as I see it) is to save the angles of the original deck, mostly around the stern so they can be copied on the new material. For new decking, I used 3/4 MDO plywood. Lots of home boat builders use this stuff too. As I recall both sides are coated in a slick paper like finish: about $100 for each 4x10 sheet. After cutting and fitting the new pieces, I coated all surfaces in Zinzinger Bulls Eye oil based primer: nasty stuff. Next I coated the undersides and the edges in a high gloss white anti-mold bathroom enamel paint. I bought the Nautolex covering from Defender, and I got the same stuff (fake white/black wood planking) that came on the boat originally. I have not applied this yet.
Although the decks are the first to be pulled, they are (for me) one of the last to go back in. I got the decks and inside skirts out in one Saturday. All screws went into labeled cans, sealed with masking tape--coffee cans or boxes. When everything is done under the deck (and I'll be cutting additional hatches) I'll re-install the decks.
Plasteak is non-structural. I would still need a supporting structure of aluminum, plywood or fiberglass. I am considering Plasdeck, which is a 1/8 vinyl that looks exactly like teak planks. This would cover any mistakes I make in the fiberglass stage. Also they have a product called Limarpa, which is a marine plywood substitute. From the sample I have it would not be suitable for a cockpit deck without a non-slip covering like the Plasdeck product. Also very pricey: about $26 sq/ft for materials. Also looked at aluminum decking products. A total floor thickness of 1" thick and would require modifications to the salon entrance for proper drainage. Would probably be a great product for bilge flooring though. I may end up using it under my new cockpit hatches. It looks like a good product (at least from the spec sheet) especially with the Divinycell core, but I'm not familiar with it. Since they don't show 5/8 “ thickness you'd have to laminate an 1/8" thick face on it.
I've been thinking I might end up using 1/8" solid teak (as I have a big stack of teak in my basement) laminated to 1/2" plywood with epoxy as a replacement cockpit sole when I get to that point.
Well, I did it. I started pulling up the cockpit decking on my 1975 Marinette 32 Express. I have several situations that have caused me to defer this big step. First, the aluminum corner-round molding is welded in place and supports the corner of the deck flooring and the side panels in the cockpit. Second, reading all about Nautolex and seeing how it was installed with wrap-around stapling, which caused the flooring panels to be screwed down from the bottom up seems a little harsh. Then there was fear, trepidation and lack of source of 5/8 “ good exterior or marine grade plywood, all of which was set in motion by my putting my foot through the deck! The decking aft of the engine hatches had some rot. The rest is very sound and I plan to save it. Most of the rot is around the stern and port and starboard drains. I took a straight-edge and screwed it down crosswise just forward of the aft hatch and set the depth of a Skill Saw to just to go through the old decking and cut through the old deck leaving 1/2 of the aluminum "t" that the old deck was screwed to, to support my new replacement panels. I made a number of parallel cuts through the old material and I used a screwdriver and hammer and small crowbar and pried/broke up the old decking aft of the cut. I used a pair of pliers and from the top, backed out the remaining screws. My plan is to replace the 5/8" plywood and fasten it from the top, either with liquid nails and weights, or with screws from the top and filling them in. Then I will remove all the old Nautolex and prep the surface with a coat of oil-based paint over the old and new ply panels and then install the new Nautolex decking fore and aft. Since I will not be able to wrap around the exterior of the plywood with the Nautolex, I will either staple along the edge with Monel staples or use West System Epoxy to anchor the Nautolex, which I suspect must creep and shrink, thus the wrap-around and staples on the original install. Next, I plan to install a new wood, or composite cove molding, hiding the original aluminum corner molding, and hiding the staples or rough edge if I epoxy. The hatches will be done as in the original installation with wrap-around and Monel staples.
Finding 5/8" plywood of any kind is like finding a needle in a haystack. The major outlets look at me like I'm not quite all there. I've started carrying a piece to dispel my ineptitude. Where have you found it? I know quite a few hearty souls have taken on this project. Can I get by with Exterior? How about pressure treated. (No! The chemicals in it will attack the aluminum.) I don't want to invest all this effort to have the flooring system buckle when the glue goes south.
I redid my floor in Plasteak, and when I replaced the whole floor and it was a big job. Under my old floor they used stainless screws and galvanized washers. Needless to say a lot of screws were minus the washers (they corroded away. I imagine my whole floor in cabin is the same. I plan on replacing cabin floor some day, but not this year. I was going to say use a thicker marine plywood and router edges to fit in track but you are talking about only doing part of the floor. This would work if you had a door wall and did every thing out side. I used stainless screws (same screws I took out) and fender washers to clamp down floor from underneath, but I also had to put in more supports for Plasteak. It has color all the way through if you scratch it I use a small floor scrubber on it, just soap, water and run the scrubber across and rinse.
First of all, I like the idea of attaching the plywood from above. Screw that crawling around in the bilge crap, ducking under this and that and getting scraped and bruised in the process! I too have thought long and hard on what to use/ how to do it when my own cockpit deck rots out (it's in good shape for now), and here's what I came up with: First of, you don't need "marine" plywood. The only difference between it and ordinary, easily obtained "exterior" plywood is the lack of voids; the glues are the same. First I'll remove the aluminum molding (mine are screwed in place, thank heaven). Next, using my favorite template material--cardboard--I'll make a pattern of the entire cockpit deck. After transferring the shape to ordinary exterior plywood sheaving, I'll cut out (a bit oversize) new pieces, then trial fit and trim them until they're just right. Finally, using several quarts of epoxy wood sealer, I'll seal both sides and the edges of every piece. Next comes the crappy part: ripping out the old deck, using a sledgehammer, saw, and a crowbar.
Time to start putting it all back together. The plywood will be placed on the aluminum stringers with a 'membrane' of some insulating material in between; possibly something as simple as two layers of duct tape--I did this when replacing the plywood in the hold. I will NOT use any adhesives, however, since wood and aluminum expand/ contract at different rates, which will fail the bond over time. From above I will drill and screw the floor down, using flathead, # 8 SS sheet metal screws, each screw countersunk below top of the plywood. The entire floor will then be coated with a light-colored truck bedliner material, applied at the correct thickness, and having enough grit in it to avoid a slippery deck.
Where you will be joining the old & the new wood, you will need to fill that joint meticulously or it’ll stick out like a sore thumb. I also suggest using the adhesive No.88 that is recommended for Nautolex. Adhesives that are used for outdoor carpeting WILL NOT DRY under the Nautolex believe me, what a horror story. Besides # 88 is a little forgiving in aligning the pattern.. Oh by the way if you’re going with the W/ B plank decking Nautolex have fun lining them hatches up.
I wouldn't use the pressure treated plywood. It has Copper Chromate for the preservative. (I believe that’s what it's called.) Not a good choice to put on top of an aluminum frame. I used 5/8" marine plywood. Most lumberyards can special order it for you.
As for measuring, now that the old decking is gone, I can use template cardboard and "deck the deck with it" and transfer to the new plywood. Treating the edges is a good touch. I don't know if I want to go so far as to use epoxy all over the new deck, as I really can't do that for the remaining old deck.
All the rot was in the stern, and it disintegrated on removal. I'll make cardboard templates. I have no fear in that area. I definitely do not want to use a contact-type cement with all the lines to line up--they'd take me to the home (nut house) by the time I tore it up the second time to re-align it all.
If you do not want to use Plasteak, how about some kind of planking in tongue and grove (maybe a hard wood) The easy thing about tongue and groove is that as you are putting one plank at a time it was VERY easy to fasten from underneath until the last plank. Even the last plank was not hard. How about some hatches in areas that you need access. I know where you can get the aluminum rings then jus cut and weld to size between supports. Just some different ideas. I am very happy with all the access
I put in it makes every thing easier, and you have areas you can access for storage.
Not sure wood will rot even faster if it's epoxied and then screwed in place. Many companies sell epoxy for this purpose, and it has a great track record. Common sense (often incorrect) would say that moisture has GOT to enter the wood quicker and easier if the entire lower portion (plus what's under that Nautolex) is unprotected. Also (doh!) I forgot to mention that every screw I'll use to secure the plywood to the deck will get "3M 5200-ed" before it goes in.
I also have to disagree that moisture will leak in around a screw installed in the above fashion. For one thing, the 'membrane' (rubber, duct tape?) below the plywood acts a lower seal, and the bedliner material above the screw will seal it as well.
On the # 88 adhesive yes it is a Nautolex product I had problems buying it in MI. I had to buy from a Ohio west marine store & had shipped in. Don’t know why. Two other things that will come in handy is a rolling pin. Also a helper
Be sure to counter-sink your scupper drain holes a tad before you seal the wood--mighty helpful in the drainage process you wouldn’t believe how much water that little 1/16th lip can stops.
I've grown to hate Nautolex! Not only is it a pain in the butt to keep clean, the surface has poor resistance to cuts and abrasion. Mine has several cuts in it already. A cut will allow water to get to the plywood below, and guess what happens next? Simply resting the skeg of an outboard on the surface is enough to chisel a cut into the damn stuff.
Once you encapsulate the plywood in epoxy its the same situation that you have with wood core in a fiberglass boat deck. The epoxy encapsulation prevents the wood from drying out during times when water is not present and it eventually delaminates and rots. I spent several months replacing the balsa coring in the cockpit floor of my 28' sailboat. The water went in but it didn't go out. All because some idiot didn't seal 4 bolt holes for a pedestal guard. Without the epoxy it has at least a small chance to do some air-drying when water is not present. It will still rot but not quite as quickly. The moisture issue with screws is not a problem when the screws are installed from inside the boat up into the plywood. What I was referring to are any screws that installed from the cockpit down into the plywood, such as the screws for the hatch, etc. I'm not saying don't use epoxy. I plan to use it when I need to replace my cockpit floor, but I'll epoxy solid teak strips around all the edges and anywhere where screws will penetrate and then core all holes with epoxy. Get a copy of the West System technical manual, they recommend this procedure.
I'm also replacing my cockpit this year--it's in my basement right now. I've decided I'm going to replace my deck with a fiberglass panel board. Haven't decided about the deck covering. My main options are non-skid on the glass, A Nautolex type covering, or Plasdeck which looks really good but costs a ton.
The main thing holding me up is that I'm not that good (experienced) with the fiberglass work and I don't want to screw it up too bad! Also have decided to go with three hatches: one on each side of the existing hatch. There will be no deck between the hatches as they will use the aluminum frame for their support. I plan on using 3/4 C channel to line the inside of the frame and create a gutter for each hatch.
Worried about the decking lasting. My decking was originally done
poorly but it lasted 29 years. I think it was the original plywood
when I replaced it. I can see any plywood lasting that long even longer if you spray truck liner on top, even with screws under the floor. What are you shooting for, 50 years or more. Any way you do it it should out last y’all!. I guess what I am saying is if the over kill is worth the trouble, only the individual doing the work can answer that. Been there and back on the over kill.
They have cheaper plastic boards at Home Depot for exterior decks but
I do not think they come in tongue and grove if they did it would be cheaper than Plasteak. I suppose it would be a lot of work to turn plastic boards into tongue and grove.
I read a article on the net about restoring old wooden boats. The writer said auto antifreeze was the best stuff for rotting wood. Its chemical base will kill anything on planet earth including the little wood rotting gremlins. It also displaces the residual water trapped in the wood. He actually drilled holes in the soft areas to inject the antifreeze. I'm thinking about painting the plywood in my boat. Might save the decking in the hold, which is starting to turn.
I found the plywood today. Choked at the last minute and popped for the marine grade: $78.40 per 4x8 sheet of 5/8".
I saw a solid composite (zero maintenance) deck board product at Menards here in Chi-Town and thought it would be great for replacing a cockpit deck. It's part plastic and part sawdust and has a 20 or 30 year warranty. It has a wood grain molded into the surface on one side and longitudinal ridges for skid resistance on the other side as an option. The literature claims it can be cut, drilled and shaped with ordinary woodworking tools. I would think you could use a table saw or router to cut tongue and grooves in the edges. Since it's solid, mostly plastic and meant for decks, you should be able to counter-sink the stainless screws from above and even use plugs if you wanted to dress it up a bit. I'm going to try it in the hold to replace the plywood floor there. At 99 cents a foot (for 6" widths) it's less than $2 per square foot. I didn't check to see how thick it is.
My point I have been making, if any one is using planks, there is
no need to screw it from above. If you are worried about the stainless washers you can use a gasket. They have vinyl by the yard at the Home Depot for shower under-lay. They screw in for top or bottom in the aluminum the same way. You are right with a Router you could make tongue and groove real easy.
Here's a thought about the question of water penetrating screw holes, then getting trapped and promoting rot. There's a product called "Git-rot" designed to replace rotted wood sections. From having read the instructions years ago, one would drill a screw hole and inject some of this liquid with an eyedropper before inserting the screw. The liquid, through capillary action, seeps into the surrounding wood, hardening and sealing it.
When comes the dreaded day I must replace the deck, I would absolutely go with Plasteak and screw it down from above. No plywood. Maybe, just maybe, add some stringers to beef up the support (which will be needed). As some of you recall, I replaced the teak bow pulpit with Plasteak some years ago. No maintenance since except for a squirt from the hose. I have paid for that stuff in aggravation-saving many times over. Love the look of Nautolex (it has lasted years) but replacement will be another material. After you get this deck replaced in the cockpit, do yourself a favor. Invest in an aft cover (Sunbrella). My 1988 has one and the cockpit looks as new as the day it was purchased: no sign of rot or discolor anywhere.
Good advice. Our 32 is in a covered slip. Keeping the sun off the boat really helps it stay pristine. We do have an aft cockpit cover we use when away from the dock or to button up for the winter.
I have a Sunbrella from West Marine that fits perfect on the back cockpit. When the afternoon sun is setting in the west, its perfect for that ever-elusive shade we have at our marina
Just a suggestion in case you do bare-footed boating. Another Marinette boater let me walk bare footed on his Stormy Gray Nautolex cockpit deck at noon time, on a sunny 80 something degree day, Unbearable. So you may give that some thought before you start the installation of a darker colored decking.
I am replacing my deck with NidaCore. It is a honeycomb fiberglass product. Works just like plywood. What may interest you is the way I am fastening it down. I epoxied (you would weld) 1/4 threaded inserts into the bottom of the panel. I then use about a 2 1/2" x 1" bar to clamp the panel to the aluminum substructure. This allows me to put the bolts and clamps on each panel before I put it into place. Once it is in place I just swing the bar under the aluminum frame and tighten the bolt with a ratchet. Note that the substructure is not totally flat. In the center the supports are welded so their tops are flush but around the outside they are welded overtop of one another. This makes putting a flat panel in a bit of a pain since the edges are higher than the middle.
I was going to go with Divinycell panels, but there was a back order on the stuff so I had to switch to Nida-Core. Price was around $420 plus $105 for truck freight for two 4x8 sheets. I used the 3/4" but if I was doing it over I would go with the 5/8 as the core is 3/4 plus a layer of fiberglass on each side. This might require two stiffeners in the aft area on my 32 but no big deal as you can make them out of the same stuff. The panels machine fairly easily. I used a plywood blade to cut them. Router (carbide tip) works fine also. The panel is basically a honeycomb core with 18 oz of woven glass on each side. I started out using fiberglass tape on the edges but low density fairing compound fills the edges in nicely. These panels are much lighter than plywood. They are supposed to be sound deadening but I don't know about that. I used a router to cut the core out from the bottom in spots and epoxied in stainless T-nuts for my hold down clamps. This has worked out (so far) really well. I haven't finished this project because I am working on the rudders and
In my last post, I talked about acquiring the Nautolex material and looking for their #88 Adhesive. I got quite an education snaking through the internet following the ownership blood line to Nautolex and the adhesive...that Nautolex never made, but had made by another vendor. Anyway, I overcame all those dicey problems and did acquire the adhesive at http://www.outdoortextiles.com for $60.00 a gallon plus $15.11 shipping. I am very pleased with the way the #88 adhesive worked. Nothing like contact cement that had me having horror thoughts. If you read any of the earlier posts, you'll remember that the 12 1/2" panels in the center of the cockpit did two things: they make up for the shortfall between the two 54" runs of Nautolex, and they eliminated the need for a butt seam where the two runs of Nautolex would come together fore and aft. I also decided to replace only the portions of the deck that were rotted. I also finally decided to remove all the old Nautolex from the entire deck, having flirted with the idea of leaving the old Nautolex down on the sound decking. The Nautolex came up very easily by running a very sharp utility knife fore and aft on each an every black seam and then heating the surface of the old Nautolex with a heat gun and running a putty knife under it stripping one plank-width at a time. Very time consuming, but requiring no thought what-so-ever. After the deck was stripped and the new decking pieces were in place, I used Bondo to fair the seams and then used a belt sander to go over the entire "new" and "old" deck.
My wife and I literally spent two solid days laying out patterns to insure that the two fore and aft runs of Nautolex would come together and meet the 12 1/2 inch panels at the centerline and have all the seams correct. This was the biggest part of the job. After we glued and laid down the first panel of Nautolex and I was crawling around fitting, I noticed that every 11 1/2 inches apart, fore and aft on the Nautolex, there is a tiny embossed series of plugs running port to starboard, simulating the plugs over the screw holes that would have held down the fake teak! I had never seen these plugs on the old Nautolex, but in examining a couple of panels I saved, sure as hell...they were there. Now with this realization, I now had to fit all the rest of the Nautolex so as to not only run the black seams perfectly, but to also have the plugs match going athwart ships! Groan. This caused more waste than I would have liked, but figured that the plugs would become all too visible when the deck became dirty. So we lined them up as well. Having gift-wrapped the four deck hatches, and having first lined up the hatches relative to each other and to the hatch holes, so the new Nautolex when attached would line up and after gluing the Nautolex down and stapling it around the blind edges, it was time to replace all the stainless steel trim. Well....this is no small job in alignment. First the newly decorated hatch has to sit in its hole and the gaps have to be perfect so the piano hinge lays perfectly and the black lines line up with the rest of the deck, and all the rest of the four trim pieces also lay perfectly. I found it easier to first use masking tape to hold the trim and keep adjusting until I felt it was as close as I could get it...then to fasten one screw in each corner to keep the whole shebang in alignment. In the Express 32, there are three center panels of 12 1/2" wide. After gift-wrapping them, and after all the rest of the deck was done, I installed them with a few blurbs of liquid nails. No crawling under the deck for me! The replacement plywood panels I screwed down from the top and counter sunk the screws and Bondo'd them prior to the belt sanding. It's done! It looks terrific! And I hope to never have to do it again.
My cockpit floor is soft when I probe it with a small screwdriver, especially around the hinges. Do you have to peel back the vinyl to apply this Git-Rot or can it be injected through a cut in the vinyl? Do you think it is worth the effort to try it or should I just replace the whole floor and be done with it? Obviously a lot less work using the gunk on the soft spots and I am lazy so a temporary fix may be adequate for as long as I own the boat. There is one are of the deck that we try to keep a carpet covering the bad spot. Maybe I can just patch in a small piece of plywood and epoxy the soft areas and relax with a wobbly pop.
I used a sharp utility knife to slice the vinyl along the perimeter under the bench seat. It’s a pain to pull up in some areas. Marinette did not skimp on the adhesive. I only have rot under the seat. The rest of the floor is fine so far--knock on wood--I’m going to remove all the vinyl under the bench seat and will have to cut out a new piece of wood for the very aft right corner. Ill dry out everything best w/ fan and maybe hair dryer or something and soak the wood w/ that Git-Rot. I’m going to leave the vinyl off under the seat. You don’t see it and if water gets under it the wood will just begin to rot again. Ill put some of that raised plastic matting to allow air to move around and water to drain. Ideally it would be great to replace entire floor but I can squeeze a few more years out of it.
The decking fits inside of the cockpit liner, no need to remove the liner. The aluminum inside molding that runs around the cockpit at the deck line is what is supposed to keep it in place. When I did mine, the worst areas of rot were always going out from the screws, there are about 60 screws in the molding so I did not replace it. After I finished the deck, I ran a bead of 3M 4200 around the inside of the cockpit. This seals the perimeter and holds everything together. I even left off all the SS trim pieces and the hatch hinge, I just lift the hatch out and set it aside like a plastic boat would. Before I recovered the marine plywood pieces with Nautolex, I put a coat of epoxy resin on all sides of everything, it's been about 7 years now and it's still solid.
3M 4200 is about 1/2 the strength of 5200 and is flexible, it's still way stronger than is needed. I was surprised at how fast the original deck degraded after I first noticed some soft spots, it seemed as though you could have stepped through the deck in some areas. One big deal is to keep the original pieces as intact as possible to use them as patterns. I would not want to have to do this job without them for there are few straight lines.
I don't want to glue the cockpit floor to the stringers. I will keep the duct tape idea in mind. I still think I need a sealer between the deck edge and cockpit sides. I guy at a hardware store recommended Lexel: $7.69 a tube.
My 32's cockpit is floored with a single sheet of foam-cored fiberglass. Apparently, the former owner laid the foam out flat, fiberglassed one side, and then put it, glass down, in the cockpit and screwed it, from above, into the aluminum deck beams. Then he fiberglassed the top and finished it off with a speckle-paint that is actually pretty nice. But the deck doesn't come up, and it is starting to look like the moon as I add access plates whenever I need to get at something. Some day it will all have to come out. But the fiberglass/foam sandwich is good stuff, and would be great if it had been made in removable sections.
At least here in Florida, you have to be crazy to use plywood, even if it is epoxy saturated marine grade.
I don't know why you'd want the diamond plate instead of Plasteak "planks" that look very nice. Because I prefer the "traditional" white and ebony look of the Nautolex I want to use sheet material. Starboard is an excellent product but they don't have it "stock" in the correct thickness AND you can't glue Nautolex to Starboard. Plasteak has a sheet product in the correct thickness and it will accept glue. Would go down basically the same as plywood. I got as far as making a luan 1/4 “ template for the rotted deck on my project 32. It will work for both sides of the boat. You just flip it over. Now what? I was going to trace it onto the 5/8 “ plywood and cut it out the deck with my sabre saw and circular saws the same way I cut the 1/4 “ template from cardboard patterns. But I had to use a sander to smooth out the curves on the template and I would have to do the same after free handing the sabre cuts. Also my circular saw plunge cuts for the straight hatch cover openings took a couple of tries. So I got to thinking, which always costs me more money, why not use a router with some sort of pattern following bit. I could tack my luan pattern right onto a 5/8 sheet and roll around it with the router. Then pull, flip, tack and roll the other side.
The first mate wanted carpet instead of the Nautolex so when I replaced the wood I used concrete form boards, they come in 4 by 8 sheets and are plastic on both sides. West Marine epoxied on all ends. Five years and like new.
Just completed replacing rotted rear deck plywood with new marine plywood and teak. Hated that old plywood vinyl covering. Used 5/8 marine plywood. Sealed all edges and drain holes with epoxy sealer prior to installation. Reused original round deck drains. Purchased 1 5/8 inch by 7 foot by 1/4 inch teak decking strips from Island Teak in Canada (great people to do business with). Used epoxy to place strips down using screws and washers. When finished I caulked the 3/16 spaces between strips. This process raised the floor approximately 1/4 of an inch. I found a screen shop that shortened the screen doors by the same amount and at the same time they tightened the screens and replaced the crappy rollers on top and bottom. I reinstalled my transom seat in the fishing cockpit and made trim strips for the deck borders and seat from extra teak. These strips replaced the aluminum concave strips used in original manufacturing. I used a small trim router to recess the drains into the deck. One cannot believe what value it has added to my 37' sedan bridge. Total time for the project was less than 2 weeks. Maintenance is simple, wash with soap and water, then rinse. Total cost was $330 for plywood (3 sheets), $550 for the teak, and $300 for epoxy and caulk (all purchased from Internet).
A couple of years ago I slipped while opening the cockpit hatch on my 28'. The stainless trim around the hatch cover cut my forearm like a knife and I ended up in the emergency ward for a bunch of stitches. If it had been my throat, I would have been dead. When I got back to the boat I tried to dull the edge with a sander, but it still has the potential to cut. Now that I am replacing the deck on the project 32', I need to find an alternative to that stainless steel knife edge. Is there a product out there that is both dull and waterproof. Some sort of rubber "L" or "T" extrusion.
I am sure there is a u-shaped piece of plastic that will slip on over the stainless edge and grip tightly. You can cut 45-degree angles in the corners, like a picture frame. Where to purchase? Probably a well-stocked big box hardware store. I've seen the stuff with little grippers inside the channel to make the hold even better.
I had a near bad experience like yours, twice. No cuts though, just bad bruises. Gotta be very careful around open hatches, I tell myself. At least, we didn't fall through them and break a skull.
Had the hatch slam shut after a Carver wake and took the skin and some meat off all the way down my leg. I like your idea. I found some interesting stuff at Tacomarine.com. They have the stainless steel trim I cut myself on but they also have some "hatch tape" to weather seal the hatch perimeter better and some aluminum "T" moldings that may not cut like the steel. Of particular interest was a hatch frame trim with a built in rubber seal, #A61-0093. I would like to get a sample of that. They don't sell direct but are hooked up with a lot of marine retailers. I'll keep looking around. They had a bunch of those little edge grippers but all for thicker stock. My edges are not that sharp, I filed them when I made new ones. You can buy a piece of SS and have it sheared to widths needed. I cut lengths with a friction wheel in a die grinder. Holes were drilled with a drill press at slow speed with oil and a cobalt drill bit. One drill bit did all my holes and was still good at end. The trick is slow speed, oil, and a cobalt drill bit.
I got the old deck out and the new deck cut. I got the correct Nautolex and glue from Defender.com. I wanted to paint the cockpit sides before I install the deck. Grinding off the old sealer between the side and deck is a pain.
The screen doorframe clamps the entire front of the deck down. The easy to reach screws around hatches go up through pre-drilled holes and come out with no problem. The hard to reach fasteners are the screw/washer sets that clamp to the frames. I managed to remove all of these but getting them all back in will be very hard. I am just too big to get way in under there. The gas tanks and rudder linkage are always in the way. The guys building the boat only used 3-4 screw/washer sets on the sides and about 3 around each drain. And they didn't even try to use the predrilled holes through the frame supports in these hard to reach areas. What I may try is to glue the screws into these pre-drilled holes from the bottom with 402, lay down the deck and reach way in to drive the screws up into the plywood. This job really requires two people. If I hadn't ordered the Nautolex I would be tempted to coat the plywood with Durabak or several coats of Schilling's rubber based Enamel (the last coat with non-skid media). Screw it down from the top into the frames along the sides and around the drains with about 14 cap screws and stainless trim washers. This would shorten the job to just a couple of days for one man and make it feasible to remove the deck for access to the mechanicals.
The tongue and grove I used had black stripes in it and when you are done you can get a plastic welder to put down between pieces. At that time they told me to put extra supports in. I did not go over 1 foot unsupported. On hatch cover I used a 3/4 backing with cedar boards for ribs. I did a lot of extra work. I made the strips on far outside of hatches so it pops out. I also got some extra aluminum ring hatches. I cut the aluminum hatches to fit in various places (welded them back together). I have no area on rear deck that I cannot get to.
Plasteak Co. says you cannot stop the deck from leaking into the bilge; the decking will breath, expanding and contracting with water and temperature. They have a one peace, 4x8 sheet that requires an over layment to stop it from leaking.
ON REPLACING THE COCKPIT DECK WITH ALUMINUM:
I laid down 1/4 inch aluminum plate and glued outdoor carpet to it. To prevent metal-to-metal rattles laid a bead of silicone on the frame before laying plates and fastened down with stainless countersunk bolts. Replaced the cockpit sidewalls with white plastic 1/4 “ sheeting, no more painting. Had to add 1/2 plating under the door track and ladder to makeup the height difference. Installed gas assists to counter the added hatch weight. Should have done this 9 years ago. No noise, easier to keep clean, no increased solar gain, no noticeable weight difference, and solid as a rock.
If you use a thin rubber vibration absorbent strip on each support, I recommend against using a carbon-rubber (natural) as it will react with the aluminum deck supports. The problem is worse if moisture collects between the rubber and aluminum.
I'm oblivious to the chemistry reasons for selecting any particular product for this application. Mechanically, what I desire is a cushion to prevent "buzzing" of the decking against the supports due to engine vibration, while allowing me to remove a piece of the decking to provide easier access when work is needed below deck. The engine room of a 28 Marinette is one of the world's very most effective claustrophobia test chambers. I crawl in through the lazarette and slither up alongside the engine and do whatever it is that I had to do, then I have to inch my way out backwards, feet first, usually on my back, including backing around the turn to return to daylight, civilization, and some degree of sanity. One of the "features" of my pieced together design for the decking is to avoid this eye-widening experience.
I wouldn't be too hasty. Diamond plate is for people wearing shoes. Which certainly would be a problem here in Florida. No one wears shoes onboard.
My 28' had the deck done in a sandwich of some sort of fiberglass between two sheets of aluminum. Vinyl was then applied to the aluminum. It was very light, designed for cargo floors in aircraft. I don't have a source at the moment, but I am sure it could be found. It looked like stock, but I have never seen another boat with it.
One big advantage with aluminum is just screwing the deck down from the top. You could also remove it easily to get at any tools you dropped behind the gas tank while working on the fuel sender. Yup; that's where mine went.
I don't know about diamond plate, but two of the later year Marinettes I've been on had aluminum decking. The deck doesn't get any hotter than the deck over the v-berth or on the flybridge. If you brace it the same way as the rest of the boat you can get away with the 3/16ths. If you want wider spacing 1/4" or 5/16" should span about 2'. It can then be painted the same as the rest of the boat. It will then last just as long. The chrome on diamond plate would be harder to maintain.
Has anybody attempted to replace the cockpit deck with aluminum? Are there any reasons not to? Why didn't Marinette do that in the first place?
I see so many good ideas on this forum. My question is: Don't you want to maintain the integrity of the original boat such as a Lyman, old Chris or other classic? It appears that we have the last of a once popular boat. Like anything else that is kept in pristine condition, to tour someone's totally restored boat is a trip into the past. Nautolex, good or bad is what was designed for the aft deck. I understand the aluminum plate floor would last forever, but wouldn't it be nice if you could have it machined to appear as Nautilex and keep that classic look?
I saw a Marinette with an aluminum diamond plate floor at Ladds Marina. The owner said it was great to keep clean--just wash it off--but that it got very hot in the sun. If you are in the area the boat is the water taxi and in always in the marina.
My first thought was that aluminum may not be a bad idea. But if I were to replace my wood floor with aluminum, I would like a nice clean weld as opposed to the corner trim. I think it would be easier to clean and look nicer. The problem lies in getting to the underside to weld everything. You've got gas tanks down there that would have to be taken out. No room down there and they might explode. In production, the tanks, plumbing, and everything else is roughed in or installed before the deck is. I guess you could have an aluminum floor installed at that time. Empty tanks could be welded over a lot easier. (Note: The floor needs to be removable, for if the fuel tanks have to be replaced...)
I hadn't really thought about making the entire cockpit deck in one piece aluminum. Welding it in would be nice but it could also be screwed down from the top and the screw head s faired in. Or you could weld clips to the bottom and fasten those with screws. I am not worried about it getting too hot since I never have that problem with any other areas of the deck (like the bow and side walkways). The other decks are supported 12" on center so I think you would need some extra bracing or thicker aluminum. I replaced the deck about 4 years ago with plywood encased in epoxy. It was not pressure treated and certain areas are not holding up well. After careful examinations I have determined that the hinge area of the hatch stays damp almost continuously and that the leverage of the hinge upon the plywood helped to cause cracks in the epoxy that let water in. I may just replace 3" or so around the hatch opening with solid wood, which hopefully will not rot. My two main concerns are a deck that will last and water tight hatches.
Have you considered a gasket under your hatch trim? One thick enough (1/8th inch plus) that you could torque down the hatch trim and get a really tight fit? I've been throwing around the idea of removing that 45 trim where the deck meets the freeboard and gasketing in between the two. Not a lot of room to work though. I then could put the trim back for what would look like an original floor. I believe water is coming in from two areas: a little around the hatch & a lot along the port and starboard sides where the deck meets freeboard. The pitch of the deck moves water to those sides and then it just sits. A gutter would be nice but not real practical. I should tell my boss I need to do some field research at the marina.
There are some Marinettes out there with aluminum diamond plate cockpit decks, probably 1/4". That might be the answer, nonskid, zero maintenance, bulletproof, lightweight and if you want to spill some lacquer thinner on it, go ahead. I think John A. could make up a set of patterns for each model and cut out deck panels on special order. The aluminum deck on a 32 could be made up in six pieces instead of four; this would make for easier shipping and would provide better access to the tanks, blowers, etc. The fasteners for the aluminum panels could be drilled and tapped right into the existing support framework. This way each section becomes a hatch removable for access.
One of the great things about the 32' Sedan that no one talks about, is the fact that all the machinery is inside the boat and not outside under the cockpit where is exposed to a lot of moisture. This makes it a little tight but the tradeoff is worth it, if any of your friends have a carver cockpit boat you know what I mean. Because of this it's not a big deal to have the cockpit deck absolutely watertight.
I have a 1966 26 that we have restored and used 0.25" anodized diamond plate for the cockpit decking. We also used 3" aluminum I beams for support. It is bullet proof. The deck is certainly hotter than plywood, but the trade-off is no comparison. No rot, easy access via surface bolts, etc. I would not do anything else. Wood and boats just do not work in my opinion. We also used 3/16" aluminum for the cockpit coaming to replace the ridiculous vinyl covered plywood there too. The boat has more of a workboat look but I love that look and that is what we wanted.
A friend of mine has a Marinette 32 Fisherman that has an aluminum cockpit deck. It's painted with white non-skid paint plus he normally has an indoor-outdoor carpet over it. Works fine.
I don't think 1/8" aluminum sheet will be stiff enough to span the spaces between the supports in the rear but you could easily double up the supports if you have the correct welder.
The nicest floor I ever saw was a factory aluminum floor on an early 90's 41. I believe the floor was constructed out of 1/8" but I don't know. When I looked in the bilge, there were supports every 10"! The nice thing about this floor other than it was aluminum, is that it was trenched on the prt/strbrd sides all the way back for drainage. Some day....
The cockpit floor on my friend's Fisherman is 1/8" aluminum and it seems to work fine. Can't say for sure if there have been any additional supports added though.
If and when you decide to re-do your cockpit deck & use diamond plate, you might want to consider the use of roofing felt cut into strips as a isolator between the two dissimilar Aluminum grades. I believe I read about this on one of the metal boat forums. It went something like this if I recall: cut strips to fit framing, glue felt strips to framing dab just enough glue to hold strips while laying decking.
Approx. Wt. per Plate in Lbs diamond plate / bright thread
1/8" x 48" x 96" = 61 lb.
1/8" x 48" x 120" = 77 lb.
1/8" x 60" x 120" = 96 lb.
1/4" x 48" x 120" = 148lb.
In case you’d like to make a weight comparison, a sheet of 3/4" plywood, 48" x 96" = 67 lb.
I don't mind putting screws in from below, I'm flexible enough to crawl around down there without much trouble, especially since I wouldn't have to do it again for a long time. Countersunk rivets would pose an ugly crevice corrosion problem I would think, but maybe not if they were covered with the liner material. It’ll be fun to remove one day if orwhen the time comes (like when a fuel tank has to come out). The reason I'm concerned with bracing, I have a rather large (450lb) friend that comes boating with me often, so it's gonna have to hold up to him.
FROM A MAGAZINE ARTICLE ON VARIOUS TYPES OF FLOORING:
Synthetic Teak deck coverings add luster and function without too much cost. Two types are PVC-based - Tek-Dek and Flexiteek - and one is cork-based - Marine Deck 2000. Due to its user-friendliness and resilience.
Boating, it seems, involves a constant struggle between heart and brain, with a similar dynamic occurring between time and money. We lust after a bright-finished classic wooden yacht-a restored Chris-Craft, perhaps-but yield to the practicalities and buy a boat that looks like a giant Clorox bottle. We drool at the sight of beautiful honey-colored teak decking, but settle for molded-in, low-maintenance fiberglass nonskid surfacing. Well, there aren’t many alternatives we could suggest to supplant a classic yacht, but there are some viable alternatives to natural teak decking. Natural teak has long been a material of choice for boat-building. Its naturally high oil content and tight grain make for exceptional longevity without the need for protective finishes. Over time, if not exposed to pollutants, teak gradually ages to an attractive silver-gray color. And it provides an excellent natural non-skid surface. Teak is classified as a "heavy" hardwood with a density of approx 930kg/m3. It shows exceptional grain strength and stiffness, along with excellent wear and durability characteristics. And it looks great. Natural teak decking isn’t without its downsides, though. From an environmental standpoint, natural teak comes from forests that are in real danger of depletion. This factor, regardless of how you feel about environmental issues, makes teak an expensive material. And while it will last for a long time without maintenance, it won’t necessarily look good that long. Soot, air and water pollutants, and spills can stain and discolor the deck in short order. A thicker deck is usually not an option, due to the high cost of teak and the amount of above-the-waterline weight that this would introduce. Applying a modern teak deck isn’t impossible, but it’s a time-consuming and fussy job, usually involving drilling holes in the fiberglass deck for screws to hold the teak in place while it’s being glued down. There’s also a good deal of caulking to do-each joint where planks meet must be caulked tokeep water from getting under the decking and lifting it. And teak isn’t particularly flexible, so dealing with curves and/or arched decks can be tricky. In recent years, synthetic options have made it possible to enjoy the look, durability, and feel of natural teak decking without many of the problems.
Synthetic Teak Decking
PVC-PolyVinyl Chloride-is a type of plastic that can be readily modified by manufacturers to match almost any desired set of physical characteristics.
It has shown up in such diverse applications as inflatable boats, phonograph
records, shower curtains, computer cases, pipes, and house siding. PVC has also shown up in the form of synthetic teak decking. It looks and feels amazingly like natural teak, and has some distinct advantages over natural teak in terms of installation, cost, and maintenance. The synthetic teak decking systems we’ve seen-two PVC-based and one cork-based-are, once installed, quite similar in appearance and texture. It looks and feels like rough-sanded teak planking (sans splinters), with a caulked strips between the planks. Rounded edge pieces, or -margin boards- make for a neat installation, and if a complete deck is desired (rather than, say, a hatch cover), you can get a wider central "king plank". Because synthetic teak decking measures just 5 mm (a bit over 3/16" thick), it’s flexible enough to conform to surfaces that aren’t flat. You install it by gluing it down to a clean surface with a two-part adhesive. One considerable advantage of laying a synthetic deck as compared to a natural wood deck is that you don’t have to drill any holes for screws, thus you don’t compromise the structural integrity of the underlying deck. And the installation is much easier than with real wood because synthetic decking can be cut easily with a sharp utility knife, and most of the caulking required for teak decking is eliminated.
Synthetic teak decking requires little maintenance-occasional washing keeps it in good shape. Pressure washing is feasible. For surface damage, the decking can be sanded, as both the color and the grain extend through the
entire thickness. Though different brands of synthetic teak decking may look quite similar, there are some major differences in design and installation.
Tek-Dek uses basic building blocks that consist of individual sections measuring 2 3/8" wide and come in 2.25-meter (89") lengths, or longer coils, if required. These sections feature tongue-and-groove joints, with molded-in "caulking" strips. When the sections are joined, the resulting deck appears to
consist of 1-7/8" planks separated by 3/16" wide black caulking strips. The sections can be laid straight, or can take a slight bend if required to conform to a deck’s contours. For applications where wide sections of straight planking are required, Tek-Dek also supplies a wider, four-plank section, which cuts down on installation time and effort. Both left-hand and right-hand margin strips are available (one with a tongue termination and the other with a groove), as are king strips. Margin boards come with either a radiused edge or a square one. To lay out a deck, first cut and fit the margins (and the king plank if you’re using one), allowing a gap for caulking at each joint. You then glue down these pieces, using a two-part epoxy, and hold them in place with weights. Bricks, or containers filled with sand are sufficiently heavy to work well here. You then fill in the remaining deck area with the tongue-and groove sections. If you use a king plank, you’ll have to custom cut the sections where they meet the plank. When the entire deck is laid out, fits, joints together with a one-part cement, resulting in assembled multi-section mats, You then pick up the mats, clean the deck, mix and apply the epoxy, and replace the mats--it’s a lot like laying flooring in the home. On larger jobs, the manufacturer recommends assembling the mats in sections, as the limited working time of the epoxy restricts you to about 20 square feet at a time. For applications where wide sections of straight planking are required, Tek-Dek also supplies a wider, 4-plank section. That, too, cuts down on installation time and effort. The cost of Tek-Dek is $24-$25 per square foot, including adhesives for the bedding and tongue-and-groove joints. The company recently extended its warranty to 10 years. This product is also marketed as P1asDECK by a company called Plasteak. PlasDECK is made in particular extrusions for specific layouts.
Flexiteek is made by a company based in Nelson, New Zealand, with distributors around the world including Florida, California, Georgia, Illinois, and Massachusetts. The sales and marketing focus is on larger yachts and production boat builders, different approach toward installation, effectively removing the "Y" from D-I-Y. Rather than having you piece the deck assembly yourself, the company asks that you make a paper pattern of the shapes you want. Then send that to a local Flexi-teek distributor, and you get back a pre- assembled mat that’s ready to be glued down, complete with margin planks. Rather than using a basic one plank-wide section as a building block, Flexiteek offers multi-plank panels--an approach that has both advantages and disadvantages. Laying down several "planks" at a time is certainly faster and easier than dealing with individual planks, but these panels don’t bend as easily as the narrower sections. The Flexiteek approach is clearly best suited for applications where straight, parallel planking is required. Flexiteek panels are available in either 1-7/8" or 2-3/8" wide "planks", and buyers can choose panels with either six or more planks, up to a maximum of 12. Caulking strips come in black or white. Unlike Tek-Dek and P1asDECK, which assemble mats by cementing tongue-and-groove joints together, Flexi-teek uses heat to weld the thermoplastic sections together - a system not suited to DIY assembly. A Flexiteek deck tends to be a bit more uniform in color than one assembled from Tek-Dek’s individual planks. The latter, we thought, looked more like natural teak due to that variation. Still, Flexiteek seems to us best suited for professional installation, or at least for installation by someone familiar with pattern-making, who has experience in fitting large surfaces, and perhaps a handy friend or two when it comes time to lay sections in place and secure them. Either way, to apply Flexiteek, the patterns you use must be submitted to a distributor for manufacture.
The cost of Flexiteek is roughly $40 to $42 per square foot, and the product comes with a five-year warranty. not so much on the DIY market.
Unlike Flexiteek and Tek-Dek, MarineDeck 2000 makes no attempt to simulate natural teak grain. Made by Stazo Marine Equipment in the Netherlands (the U.S. representatives operate out of the Stazo office in Thomaston, ME, and Marquipt in Pompano Beach, FL.), MarineDeck 2000 consists of highly compressed natural cork particles in a polyurethane binder. Cork, in this application, has superior thermal and sound insulation properties, as well as being highly resistant to damage from UV light, saltwater, and even chemicals. The pressed cork is cut into planks, that, once assembled, and seen from just a slight distance, look remarkably like real teak decks. Like Flexiteek, MarineDeck 2000 is advertised for express use on larger vessels where broad expanses of deck require replacement. While the product is made in interior and exterior grades, we tested only the exterior version. According to the manufacturer, the exterior decking material can be sealed, if desired, with a polyurethane coating, but its not necessary. An uncoated deck will absorb very little moisture, and provide superior traction. A coated deck will resist staining better, and be easier to clean, but won’t provide as much traction. A UV inhibitor in the coating would obviously be of benefit, but coating the deck would bring you back into the endless cycle of periodic refinishing = which teak decking is supposed to eliminate. The planks come in four sizes: normal, narrow, margin, and king plank.
All are 74" long, and vary in width and thickness. The material is guaranteed for 5 years. A company rep said that untreated MarineDeck 2000 will tend to darken and gray, within a few months in the sun, much like regular teak will, but then a few months later it seems to come back to a natural teak color. MarineDeck 2000 costs $28 to $29 per square foot (exterior grade), which includes adhesives and all other materials, and comes with a five-year warranty.
Torture Testing Deck Materials:
We started out by making a small (roughly 2’ x 2’) deck section with each of the three products, using a sheet of rigid fiberglass as a sub-deck. We followed (and evaluated) instructions, and (if we thought they were required) we used manufacturers’ technical support. We determined how easy it is to cut, caulk, and assemble each. Once this was done, we set out to subject each deck to systematic abuse. We won’t be evaluating long-term UV resistance in this case, other than to report on the condition of our samples in a year’s time. We dropped heavy objects onto each deck - a plumb bob from 6 feet - to evaluate dent resistance. (Natural teak decks are sometimes subjected to this kind of damage.) We repeated this after chilling the deck to below-freezing to see if embrittlement occurred; we tried it again at 1500 F or so, a temperature that a deck can reach under the tropical sun. While we were at it, we checked to see how the heated deck felt to bare skin. We evaluated non-skid properties by placing a weighted "foot" on the "deck", and then tilting the deck until the shoe skidded. We tried this with both a wet and dry surface. And, to reassure us that our measurements were meaningful, one of our testers stood on each "deck" and made subjective evaluations of how slippery each was. One of the major claims made for these synthetic teak decks is stain resistance. We went out of our way to stain them, using gasoline, dirty oil, anti-freeze, coffee, and whiskey. We allowed each mess to remain on the surface 24 hours, judged how bad it looked and then tried to remove it by scrubbing with a mild detergent and a soft brush. As part of this ongoing test, we’ll put each panel out in the sun in an area where it will be subjected to weather, pedestrian traffic, and general wear and tear. As other nasty ideas arise, we’ll try them. We’re anticipating an opportunity to work out some of our aggressions, as well as the chance to study what looks like an interesting and useful group of products.
We’ll know a lot more after our extended exposure tests are completed. We do have some fairly clear initial findings, though. All three teak replacements-- Tek-Dek, Flexiteek, and MarineDeck 2000--can provide a good-looking, stain resistant, low-maintenance deck at a lower cost than natural teak. All three have non-skid properties comparable to teak, both wet and dry. All are more resistant to scarring and denting than teak. All are lighter than teak, which is a consideration if you’re trying to keep above-the-waterline weight down. So far, Tek-Dek and MarineDeck 2000 have exhibited the best resistance to staining and the easiest clean-up. All three are appealing alternatives to traditional teak decking, but we’d put Tek-Dek ahead of the others due to its more DIY-friendly nature. Regarding longevity, we’ll have a much clearer picture of which one is best in six months or so.
Flexiteek Americas, Inc. 954/973-4335, flexiteekusa.com.
PlasTEAK 800/320-1841, plasteak.com.
Tek-Dek International 604/880-3737, tek-dek-international.com.
MarineDeck 2000 (STAZO Marine Equipment) 207/354-0914, stazo.nl,
Value Guide: Synthetic Teak:
Product: Teak-faced Tek-Dek/ Flexiteek MarineDeck
Plywood PlasDeck 2000