Condensation......

[Maine Sail]

Just thought some would like to see what happens when you leave wet bilges and an uncovered boat in the winter ......


2' of snow sitting directly on-deck, flag blue hull, bilge full of pink stuff, cabin temp 43F deck temp 31F, exterior air temp 48F......

The entire interior of this vessel had created its own eco-system and everything was sopping wet........ Owner has "never seen any signs of condensation".....

The foam in the headliner is sopping wet, rust is forming on anything that can rust and interior varnish and wood work is suffering. Boat was otherwise pristine before this owner decided to leave her uncovered this winter..........

Air & sun heat hull and cabin warms, deck does not warm due to snow sitting directly on it. Bilge full of water and boom perfect conditions for condensation and a mini eco-system.....

So when you are wondering about why we cover boats in the snow belt, and keep bilges dry in the winter, this is why....

 

[MrBill_FLL]

we get that much humidity / condensation down here.

so, what do you do about it? -leave a lightbulb on? (low heat)

 

[Charlie Jones s/v Tehani]

and ventilation, ventilation, ventilation, with air flow

 

[seadaddler]

Ditto

Fans and dehumidifier really helps but it's not easy here either.
Nick

 

[ifmdalvey]

Cant imagine how much mould must be growing in all the hidden bits.

 

[Ron20324]

...So when you are wondering about why we cover boats in the snow belt....

Oh.... did you get some snow up there ???

 

[redhead78]

color

This will be accelerated with the darker hull colors correct??....lighter will reflect the heat...I remove the snow and ventilate once a week , and have not had condensation that is noticable. Although 2 years ago in winter on one of my sunday visits I checked the engine bay and found water in the bilge, and my brand new shiny red Beta 35 was wet with condensation. I removed the water from bilge, now and leave the engine bay open. I spray it with armour-all and cover it with a cotton blanket seems better. Boy does that sound lame,after I say it out loud.... seems to work, as long as the admiral doesn't find out....Red

 

[Gunni]

That guy has a leaking boat (and poor ventilation). Anti-freeze laying deep in the bilge doesn't do that. A warm cabin melts voids in the snow cover on deck, ice dams create pools around all kinds of compromised places for the melt to get in. An uncovered companion way being a prime suspect, but leaky hatches, ports, chainplates, mast partners / mast wiring, stanchions, deck hardware, toerails, are among the many places for standing water to get in. He just didn't notice or care during the summer when he had good ventilation. I've seen too many boats turned mossy green inside and out to trust a cover for protection.

 

[Maine Sail]

That guy has a leaking boat (and poor ventilation). Anti-freeze laying deep in the bilge doesn't do that. A warm cabin melts voids in the snow cover on deck, ice dams create pools around all kinds of compromised places for the melt to get in. An uncovered companion way being a prime suspect, but leaky hatches, ports, chainplates, mast partners / mast wiring, stanchions, deck hardware, toerails, are among the many places for standing water to get in. He just didn't notice or care during the summer when he had good ventilation.

This particular boat has zero deck leaks, I worked on it all last summer, multiple pouring rain days, its bone dry from above.. It is a Downeast style power boat so no companionway to leak. Cockpit is covered but coach roof and cabin top are exposed.

This is what happens when you let snow sit directly on decks and it gets warm and you have a wet bilge. I see this repeated over and over all winter long when I set foot on uncovered boats with snow on the decks. I don't have too many that are left uncovered as folks tend to learn. I was very surprised this owner decided to do this with this boat.

I just don't see these issues on well covered boats with dry bilges but I see them regularly on warm days when snow is sitting directly on the deck of an uncovered boat..

I got most of the AF out of his bilge for him, got the snow off the deck, and the boat has been drier. Unfortunately I can't get it all because the sump is such that I can't get my pump to it all the way due to the steering and AP pumps being in the way. He has no pooled water anywhere but the skeg/sump...

The day I took that pic I had to go to another similar boat, that same warm day, it was covered and inside she was dry, no condensation. She also has a garboard drain in the aft end of the skeg so the skeg sump was dry.. Just a few hours apart one covered one uncovered both had dark hulls both similar style boats one snow covered and sopping wet and the other covered and dry...

Only about 5% of the boats up here don't get covered.

I've seen too many boats turned mossy green inside and out to trust a cover for protection.

Mossy green? In the winter? Rarely if ever do I see that up here unless someone left it covered all summer and never used the boat. Our boats have been covered every winter since I was a kid and zero mold issues.

This winter I came out really late and we had an early storm before I could get the cover on. I had about 4" on the decks, for just two days, and even with a bone dry bilge she was still condensating slightly when it warmed up the second day. I got the snow off the decks asap... A good cover will be well ventilated but keep snow off the decks....

 

[Scott T-Bird]

We've had over 2 feet of snow on our roofs, decks and yard this winter and for a while only the top rail of my backyard fence was visible (they call it a 3-wire winter in Steamboat Springs). And with the typical NJ habit of getting freezing rain that accompanies many of the snow storms this is one winter that I was happy to have the cover on the boat. The only thing I worried about was if the heavy snow was damaging the cover. Recently, I was at least able to verify that the cover was fine. Our yard won't let me take a ladder out to the boat when we have this much snow and ice, otherwise I would love to check it out inside. Freezing temps this week are preventing any more snow melt. I predict the ice is going to last into the 3rd week of March (if not April). It's going to be a late launch once again this year.

 

[alexco38]

Someone introduced a framless winter cover to the club last year. A few boat has it. It's a cover that sit on the deck instead of a frame. The cover has slits around the stanchions. I would think it has the same issue with snow on top.

I am not a fan with snow directly on top of the deck even with a sheet underneath.

What's your opinion?

 

[Gunni]

Maine; That stuff is crazy! Maryland is much more shorts-friendly, does not require a plastic chapeau for your boat, and our "bugs" are pretty tasty too! Come on down!

 

[thinwater]

Ventilation? In Texas, perhaps, but not with freezing water and snow on the deck; the deck temperature is below the dew point.

Hehumidifier? If that does not work perfectly, then you have leaks or still have a vent open somewhere (with dehumidifiers you close EVERYTHING or you are just drying the county). The bilge must be dry, of course. And most boats yaers do not allow power.

Antifeeze? That will lower the vapor pressure of water, but unless at least 35% glycol I would not expect the difference to be important (I built a 20,000 gal/day glycol distillation unit some I'm pretty sure of the math). It is only at very high concentrations that the effect is strong. Remember that the pink stuff is generally only ~ 25% glycol.

Other than a dry boat, everything else is just "hoping" in Maine, I'm sure. The math (temperatures and humidity) are in a whole different range than most responders have experienced.

 

[Charlie Jones s/v Tehani]

The math (temperatures and humidity) are in a whole different range than most responders have experienced.

And sincerely hoping to NEVER experience. We had a foot of snow Christmas eve, 2004 here at my house. First measurable snow fall in 105 YEARS!!

By New Years day, it was 80

 

[tommays]

It is so worth the trouble just so the decks stay clean and it is easy to do projects over the winter

 

[weinie]

Wow... that's amazing MS. It's kinda counter intuitive because one would think a boat sealed up in plastic would trap water inside whereas one not covered would breathe better. I almost cheaped out this year on the shrink wrapping, but seeing this post, it was money well spent! Thanks as always! :theman:

 

[NoAgenda]

We had a friend show us show us how to do the shrink wrapping last fall. It wasn't that hard and had a good time with friends to end the season. Every time I visit the boat I am amazed how clean and dry she is.

 

[redhead78]

shrink wrap

Anybody know the going rate for shrink wrap a 38' sail boat mast-up wf an entry door. Northern NJ area..W.A.G. ??? Red

 

[Bob J.]

It is so worth the trouble just so the decks stay clean and it is easy to do projects over the winter

That's pretty sweet !

 

[25yearslater]

What might be a greater concern is the back of that panel that is likely to remain moist even though the exposed surfaces dry. Less ventilation on the enclosed spaces. I would be more inclined to shower with a toaster than turn the power on to that.