Calcium Chloride, Will it eat my M?

Fresh & Waste Water Systems, Climate Control, etc.
Studini
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Calcium Chloride, Will it eat my M?

Postby Studini » Mon Nov 19, 2018 7:14 pm

So I put a bunch of calcium chloride “B-dri” in my cabin to help keep moisture down but then started thinking I’ve seen chlorine airborne in a pool room eat out copper heat exchangers in pool heaters... any chance of calcium chloride affecting anything on the M?? First time with the M in winter.. just nervous..
88 32’ Fisherman
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EWRice
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Re: Calcium Chloride, Will it eat my M?

Postby EWRice » Mon Nov 19, 2018 8:35 pm

I know it destroys steel when in contact (look at old tractor rims that have been loaded). Brass gets a light green haze on the surface, but I can't recall seeing the affects on aluminum. I would think it would be similar to salt. Might only affect it with contact.
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ddependo
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Re: Calcium Chloride, Will it eat my M?

Postby ddependo » Tue Nov 20, 2018 7:16 am

I believe it will cause pitting if it comes in contact with the aluminum.
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jralbert
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Re: Calcium Chloride, Will it eat my M?

Postby jralbert » Tue Nov 20, 2018 12:31 pm

I assume it's in a plastic container, sitting on a counter, not in contact with the hull. If so, it shouldn't be a problem. I used moisture absorbing stuff for years with no visible effect. There's another product - I apologize, I cannot recall the name -- that was good at reducing mold. It released a chemical that fought the airborne mold spores. Sold at West Marine

I also had a solar fan in the foredeck right over the v-berth. It ran continuously and kept fresh air flowing thru the cabin.
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Studini
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Re: Calcium Chloride, Will it eat my M?

Postby Studini » Tue Nov 20, 2018 5:01 pm

jralbert wrote:I assume it's in a plastic container, sitting on a counter, not in contact with the hull. If so, it shouldn't be a problem. I used moisture absorbing stuff for years with no visible effect. There's another product - I apologize, I cannot recall the name -- that was good at reducing mold. It released a chemical that fought the airborne mold spores. Sold at West Marine

I also had a solar fan in the foredeck right over the v-berth. It ran continuously and kept fresh air flowing thru the cabin.


Yes you got it! Just setting in the containers. I like the solar fan idea!! It’s my first winter so hot m not actually sure what to expect with moisture or mold.
88 32’ Fisherman
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jralbert
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Re: Calcium Chloride, Will it eat my M?

Postby jralbert » Tue Nov 20, 2018 8:59 pm

By the way, those calcium chloride things do work so well they collect a lot of moisture - use a container that's large enough to accomodate it. Finally, one thing you can do to create air flow if you don't have a fan going is to crack a window or two but make sure they are covered well enough on the exterior so water doesn't get blown in - a little tricky.
-joel-
former owner 1988 '32 FB Sedan
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bpboater
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Re: Calcium Chloride, Will it eat my M?

Postby bpboater » Wed Nov 21, 2018 9:13 am

Moisture absorbers are only effective in air tight compartments. At 70F and 40% RH, air contains about 10 grams of water per cubic meter of air. In a 32 foot Mrinette, there are about 60 cubic meters of air space. So, if there is absolutely no air exchange in the boat,you would need to collect 600 grams of water, or 20 ounces of water to get rid of all the moisture. I would guess that a 32 marinette with the standard windows and vents will exchange the air inside the boat about every 6 hours. So, in 24 hours, you would need to absorb about 80 ounces of water to make the air completely dry. Just reducing the relative humidity below 60 % is very helpful in preventing mold from growing. But, in the long run, abvorbing 20, 80, or even 200 ounces of water over a winter will do little to affect the relative humidity in the boat. Just take humidity meter and measure the relative humidity before and 7 days after you put the calcium chloride container in the boat.
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Re: Calcium Chloride, Will it eat my M?

Postby jralbert » Wed Nov 21, 2018 4:01 pm

Follow on to bpboater's reply: Good thinking and analysis. The moisture things do work, but as bpboater points out, they only pull out a tiny fraction of the moisture inside the cabin over time. Like trying to propel the boat upstream with a paddle. So, while they "work", they don't resolve the moisture problem
-joel-
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Studini
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Re: Calcium Chloride, Will it eat my M?

Postby Studini » Wed Nov 21, 2018 7:04 pm

bpboater wrote:Moisture absorbers are only effective in air tight compartments. At 70F and 40% RH, air contains about 10 grams of water per cubic meter of air. In a 32 foot Mrinette, there are about 60 cubic meters of air space. So, if there is absolutely no air exchange in the boat,you would need to collect 600 grams of water, or 20 ounces of water to get rid of all the moisture. I would guess that a 32 marinette with the standard windows and vents will exchange the air inside the boat about every 6 hours. So, in 24 hours, you would need to absorb about 80 ounces of water to make the air completely dry. Just reducing the relative humidity below 60 % is very helpful in preventing mold from growing. But, in the long run, abvorbing 20, 80, or even 200 ounces of water over a winter will do little to affect the relative humidity in the boat. Just take humidity meter and measure the relative humidity before and 7 days after you put the calcium chloride container in the boat.



Bpboater, thank you! That’s a lot of info! So the boat will be wrapped so i assume that may help with air exchange? So I guess I should not be that worried about the chemical reaction to the aluminum but more about the moisture content? Any suggestions on moisture removal? Maybe a solar dehumidifier?lol
88 32’ Fisherman
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bpboater
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Re: Calcium Chloride, Will it eat my M?

Postby bpboater » Thu Nov 22, 2018 6:29 am

I would suggest two things that are important. first, get all the water out of the bilge and open water sources, like the toilets. Next, create natural vents, so air can flow through and remove humidity that might build up under the shrink wrap. If the boat is shrink wrapped, you could leave the windows open a bit, so humidity is free to come and go. Maybe leave the hull portal windows open so the boat can breathe.
1988 41 Marinette
Twin Crusader 454-350 hp closed cooling
Westerbeke 8.5 kw BTG
Lake Cumberland, KY