Afraid to install transducer on aluminum boat.

A/C & D/C Wiring, GPS, Radios, etc.
nascarjonb
Tin star
Posts: 30
Joined: Sat Oct 31, 2015 12:39 pm

Afraid to install transducer on aluminum boat.

Post by nascarjonb »

I'm a new owner of a 1986 28 foot BigM, I have a lowrance elite 5 gps/ depth finder/ fish finder I would like to be able to use on either boat via a mounting bracket. ( I have a Grady white center consul) I have the brackets but I'm having a hard time deciding on what transducer to use... I'm also afraid to drill threw a aluminum hull. I have only had experience with fiberglass. Should I use a transom mount? Or a threw hull? Or a shoot threw hull??? Has anyone had experience with this? Also so pics would help if anyone has any....
Thanks
1986 28 fisherman
twin chryser 360's
Marblehead, Ohio
SunbeamIV
Tin star
Posts: 42
Joined: Fri Aug 14, 2015 5:47 am

Re: Afraid to install transducer on aluminum boat.

Post by SunbeamIV »

I am also a new owner and have the same questions. Shooting through hull has ben my preferred method on fiberglass, but probably wouldn't work through metal.

I look forward to the forum's advice.
Scott, 32' 1989 sedan flybridge
Located: Edgewater Yacht Club
Lake Erie
User avatar
GB49
Royal Aluminum Star
Posts: 206
Joined: Sat Jul 12, 2014 8:23 pm
Location: Catawba Island, OH.

Re: Afraid to install transducer on aluminum boat.

Post by GB49 »

In my opinion transom mount is for trailer boats.
Have never used or considered shoot-thru puck. I've read it works on AL hulls but would need to do more research to verify.
I have only used nylon thru-hull ducers. If you use bronze, try to keep it isolated from hull as much as possible with nylon sleeve/ring/washer.

Fairing blocks only from Plasteak or StarBoard. Do NOT use wood fairing with nylon ducer or it may expand and crack nylon.
Use hole saw to drill ducer stem hole (measure 5 times, cut once), use 3m 4200 or 5200 to seal everything. Hand tighten and use wrench to snug, don't over tighten.
Goes much better with 1 person in and 1 person out.
Note on the 3M products. The 4200 is easier to remove in the future but I like to use 5200 in case the ducer get broken off while under way. Less chance of it falling out of the hole.
Use gloves when handling the 3M stuff, Its can get messy.

-Karl
1986 Sedan 32'. Twin Chrysler 360in^3, 275hp.
Forum member since 1998.
balthaus
Aluminum Star
Posts: 163
Joined: Thu Sep 11, 2014 7:27 pm
Location: Southern Indiana / Louisville

Re: Afraid to install transducer on aluminum boat.

Post by balthaus »

I think that I read on this forum that using a transducer to "shoot through" the hull will not work on BigM .
I can't remember if it was because of the Aluminum or if it was the thickness of the Aluminum.
Our BigM has a transom mount currently.......and I have not bothered to hook up the ancient Lowrance unit yet. I probably will just to see how it works though.
1984 32' Sedan FB
Twin Chrysler 360's
1.52:1 Velvet Drives
Raw water cooled
Ohio River
Fastjeff
Site Admin
Posts: 1521
Joined: Sat Jul 12, 2014 5:06 am
Location: Rock Halll, MD

Re: Afraid to install transducer on aluminum boat.

Post by Fastjeff »

I used a Huminbird transom mount on my 32 footer and never had a problem. You'll need to spring for the cable extension kit--a bit pricey.

Jeff
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington
Aquaholic
Tin star
Posts: 78
Joined: Tue Aug 04, 2015 8:52 pm

Re: Afraid to install transducer on aluminum boat.

Post by Aquaholic »

This post is timely for me.....I bought a Lowrance Mark4 this winter and had hoped/intended to buy a through hall transducer but have come to find out from their tech that one does not exist for thus unit :-( so.....I am going to attempt to use the transom mount that came w it. Jeff, where do you have yours mounted at on the hull? Any chance you have any pics? I'm a bit of an idiot and definately have much to learn about my new M! I am not even certain exactly what/where the existing transducer is ;-) .....I believe it's original. I tried this afternoon to trace the wire, but cannot see where it goes to the hull/transducer.
Aquaholic
1989 32 Marinette Sedan "Aquaholic"
1973 28 Marinette Express "Easy Does It"
McConnelsville OH
Muskingum River
nascarjonb
Tin star
Posts: 30
Joined: Sat Oct 31, 2015 12:39 pm

Re: Afraid to install transducer on aluminum boat.

Post by nascarjonb »

Thanks for the input. My lowrance is 2 years old so transducers are in abundance for it. If i do a transom mount... Does the bolt go all the way threw the hull??? What should I use for sealant on a transom mount??? Also for a threw hull all they offer is brass.... Not sure how that would work to iscolate 100 percent this is why I'm leaning toward transom mount.
1986 28 fisherman
twin chryser 360's
Marblehead, Ohio
User avatar
GB49
Royal Aluminum Star
Posts: 206
Joined: Sat Jul 12, 2014 8:23 pm
Location: Catawba Island, OH.

Re: Afraid to install transducer on aluminum boat.

Post by GB49 »

Thru-bolt the transom mount and use under the water marine sealant like 3M 5200 or Marine Caulk etc. Use stainless clam shell above water line to pass cable into boat and seal that hole with caulk. Stainless sheet metal screws for clam shell will suffice.... Just caulk everything.

Check Navico for ducer options.
http://store.navico.com/Sonar

Here is a nylon unit. Its similar to the ones we are using with the Garmin fishfinders.
http://store.navico.com/Products/000-0136-02
1986 Sedan 32'. Twin Chrysler 360in^3, 275hp.
Forum member since 1998.
jralbert
Site Admin
Posts: 885
Joined: Fri Jul 11, 2014 9:15 pm

Re: Afraid to install transducer on aluminum boat.

Post by jralbert »

nascarjonb wrote:. If i do a transom mount... Does the bolt go all the way threw the hull??? What should I use for sealant on a transom mount??? Also for a threw hull all they offer is brass.... Not sure how that would work to iscolate 100 percent this is why I'm leaning toward transom mount.
Mfr installation instructions are usually pretty detailed on mounting instructions. Meanwhile, I know Jeff had great success with his transom mounted unit. I've had both. While the transom mount worked pretty well, the thru-hull had the edge (for me). I recall that the procedure involved slightly oversizing the hole so the metal mount didn't actually touch the hull and the hole was well caulked to fill the small gap.
-joel-
former owner 1988 '32 FB Sedan
Chesapeake Bay
twin 318 / 240 hp
Potomac MD
Fastjeff
Site Admin
Posts: 1521
Joined: Sat Jul 12, 2014 5:06 am
Location: Rock Halll, MD

Re: Afraid to install transducer on aluminum boat.

Post by Fastjeff »

I drilled a couple of holes and sheet metal screwed it to the transom (with silicon on the threads). Piece of cake!

Jeff

PS: Remember, you'll need an extension cable to reach the helm.
Attachments
Swimladder.JPG
Swimladder.JPG (11.55 KiB) Viewed 13275 times
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington
Post Reply