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Insulation

2K views 14 replies 13 participants last post by  Minnewaska 
#1 ·
We're sailing on Georgian Bay where things are always still quite cool in May and early June, (with temperatures below freezing overnight in early May) but our season is short so we try and get started early. When we purchased our Catalina 36MkII we also got Espar diesel heating installed to help extend our season. Great idea, but not so good in reality.

The problem is condensation, with everything dripping in no time flat, from the un-insulated ceiling and especially the (metal frame) hatches.

I do not believe that there is a real solution to this problem. It would take quite bit of work to do a good job installing a false ceiling, which would not get rid of the insulation from the hatches. However, I am putting this out here for comment in case you folks out there have a smart idea about this!
 
#5 ·
Thanks, KellySails... I rather doubt that bubble pack will be "neatly installed" but may be useful inside cabinets against the hull.

ChucklesR... good point, but, after the divorce, I probably have no boat to worry about any condensation within it... And, the sailing and scenery is quite good while the season lasts...
 
#6 ·
A good insulation for boats is Armaflex sheets. You should be able to find threads on that topic. I am surprised your Catalina doesn't have a headliner. Wasn't that standard on Cats?

As for your condensation problem, you need to reduce the relative humidity in your boat. The easiest way to do that is to introduce more fresh air into the boat, and exhaust some of the moist air. Modifying your heating system so that it draws some outside air into the return air of the heater may help. The positive pressure created by the addition of outside air will naturally force some of the moist air out through a vent or partially open port light. The last thing you want is to seal up the boat tight. Fresh air is the key.
 
#7 ·
Flandria, there are only two ways to get rid of condensation. Get rid of the moisture in the air, or keep it away from the cold materials. No magic. So either you need to supply more heat, which will drive off some humidity and heat the interior past the condensation point, or you need to dehumidify, or you need to insulate the overhead. That's probably the most practical, to look at insulation sheets or padding, and to use removeable inserts to "plug" the hatches as well. Just a piece of closed-cell foam with velcro on the sides may be all you need for that. If you need the light to come through, try layers of the smaller bubble-wrap instead.

This is one for "brute force" though. Heat, or insulation, and you keep going until it stops dripping.
 
#8 ·
There's a ton of threads on this subject here with alot of good advice from liveaboards like WingnWing. Try searching the site, you'll find some good stuff to address your problem.
 
#10 ·
I've lived aboard in BC year round, for decades, in extreme comfort. The trick is lots of foam insulation sprayed into my steel hull. Any piece of steel the size of your fingernail which is not covered by at least a half inch of foam will drip like a leaky faucet. I believe fibrglass is not much different in that regard . A friend who sold his spray foamed steel boat and bought a fibreglass one said living in the fibreglass hull was like living in a block of ice, by comparison.So the trick is start cutting and gluing in foam, a bit at a time. The thicker the better. You can do it over time and each piece of foam you glue in will improve the comfort level.
A false ceiling with an open air space is not much insulation, and wont do much.
 
#12 ·
We have lived aboard in Toronto for 16yrs, never had a condensation problem.
We bought 4X8 sheets of 1" thick pink insulation foam board and cut it into 3" strips and bedded it in silicone to the entire hull but for the engine compartment. The trick is a tight fit as any air getting between the foam and the hull defeats the purpose.

For winter our windows all have heavy fabric blinds and hatches are sealed with the clear plastic shrink kits you can buy at the hardware store. Our two solar powered vents take care of the fresh air requirement.
 
#13 ·
We've noticed a friend's C34 sweating quite a bit in the off season with an espar going. I think running a dehumidifier even between trips will keep the moisture content down to some degree, but of course once there are 'breathers' below, heaters going and hatches closed the moisture builds up quickly - any cold surface is going to sweat, and port frames and hatch frames are pretty good cold conductors.

Though it's a pain and not very pretty you might find that a tarp stretched over the cabintop might provide an insulating buffer of air.

It's tough to apply the various bubble wrap style insulation to a molded F/G headliner that's already installed.... so you gotta think outside the box, I guess...
 
#15 ·
As mentioned, if you insulate, you have to keep the cold moist air from being able to get around the backside of the insulation. It will condensate there and mold will grow. Spraying it on, or sealing it against the hull are the only effective methods. However, I still don't think you can really conquer this one. It will find its way behind a cabinet or beneath a bunk. It's just a problem.

Are you at a slip with power? Personally, I think the only real solution is to run a dehumidifier.
 
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