Cabin condensation

[Gene Stebbs.]

In the construction industry we used to hear the painters talk of "vapor barrior paint" which eliminated the need of a visqueen vapor barrior on the exterior walls prior to putting in the FG insulation, would this/has anyone tried this to reduce cabin condensation on uninsulated C Dory cabins?

[rogerbum]

[ssobol]

I don't think vapor barrier paint will help. The condensation is not coming through the cabin walls but being generated from the inside and condensing on the cool/cold surface. The only real solution is to keep the inside surface warmer than the condensation temperature of the inside air (depends on relative humidity). Insulation or internal heating of some sort is required.

[Sunbeam]

In the meantime, I can recommend a "The Absorber" cloth for wiping down the walls/ceiling in the morning (check automotive section for them; they come in a plastic tube shaped sort of like a can of three tennis balls). Not as good as preventing it (which I understand is your goal), but makes wipe-down relatively painless.

[AstoriaDave]

[Gene Stebbs.]

Thanks, I was doubtfull but curious, I saw some thin insulation materials in an older post I may look into that. I know metal framed windows are a nightmare for condensation the housing industry battled that for years until the plastic/synthetic window frames came out. I had a hard time trying to convince some customers that they did not have a roof leak until I mentioned that it had not rained for two weeks but hey had water running down the widows and walls below the widows, particularly bad in mobile homes. I am just looking atall the issues I may have to deal with and be prepared with answers much in advance of a purchase, thanks again for taking the time to humor amdrespond to my repetitive questions

[thataway]

Insulation will help--but you still have to look at surfaces such as the forward hatch or windows. It is always possible to make insulation inserts which fill the hatch, or windows.

We are using back packing pads on the sides of the V berth, as well as under the bunk cushions.

Once one puts in permanent insulation, generally the utilitarian nature of the unlined simple interior. I have seen mold in several of the boats from the factory which have the headliner, and walls lined with the vinyl/foam material.

[Marco Flamingo]

Before anybody gets too excited about insulating paints, you might want to read something like this article.

http://www.greenbuildingadvisor.com/blogs/dept/musings/insulating-paint-merchants-dupe-gullible-homeowners

There are also some FTC cases where paint companies have been sued for fraudulent claims, but this article sets it out. I came across these paints when I built a home a few years ago. Sometimes the claims, like R-10 insulation value, is walked back to mean "R-10 per inch of paint thickness," which the FTC rightly asserts (and the judge finds) to be misleading.

Even still, I'm thinking about applying some insulating paint to my boat now that it's completely torn apart and I wouldn't have to mask very much.

I think that I can make insulating paint cheaper and better than any of the marketed products that I've seen. A gallon of mold inhibiting white paint (like Kilz or Zinsser) is about $25. Mold inhibiting paint is what I want on a boat where condensation is an issue. A half gallon of glass microballoons (the secret ingredient) is about $15. Because the manufacturing of the tiny glass orbs leaves a slight vacuum in the middle, microballoons are often claimed to have magical properties when creating "insulating" paints. Not really magical, but they do have more insulating value than the regular solid particles in paint.

A gallon and a half might be more than I need for the V berth on a CD 16, but thicker is better. It's the "thicker is better" part that limits the effectiveness of paint as an insulator. When you visualize a half gallon of "insulation" (in this case the volume of the microballoons) spread out over the area to be painted, that's not much insulation. But if the purpose isn't to stay warm, but rather to reduce condensation, adding a little R value could be part of a solution.

Mark

[ssobol]

I painted the interior surfaces of my cd 22 cruiser with 3 coats of HydroTech SC#1000 paint followed by three coats of latex home paint (from HD). While I don't boat in the PNW I found that this treatment may help. In the v-berth area sometimes the walls and roof can feel a bit "clammy" in the morning after an overnight stay, but there is no visible moisture, nor does any come off when the surface is wiped. We have spent overnights on the boat in VA in December.

Sometimes in the main cabin there is a film of condensation (you can see a difference if you swipe your finger) on the roof. This usually happens after cooking with the butane stove or using it to heat the cabin. This goes away by itself and does not require any wiping up.

Whether I am just lucky or this treatment is helpful, I don't know. I did this first thing when I got the boat (based on issues I read about here), so I don't have a before or after comparison.

http://www.hytechsales.com/prodsc.html

[Aurelia]

We have use the SC1000 product in two boats and it really does have a worthwhile effect. The sound deadening properties are significant and I have even tested that with a DB meter. The thermal insulating properties are relatively slight but are enough to nearly eliminate condensation on our interiors for northwest year round use.

Greg

[B~C]

Damn Roger, you're making me feel old. This is be nice on the internet day, stop cyber bullying me.

10 years, where do the years go? Concerning the goo I installed and painted over ten years ago- I still like it, it looks good, and it helps. What I like about it is that if you didn't know it had been treated, you would never notice it. I think a bit of insulation and some ventilation really helps with the condensation problem.

[breausaw]

I used Flex Form marine carpet in our V-birth, 3 years holding up well.

http://www.c-brats.com/modules.php?set_albumName=album1789&op=modload&name=gallery&file=index&include=view_album.php

[Gene Stebbs.]

I may just look for a Venture 26' when the time comes, I really wanted the difference in weight twixt the 25 and 26 to be taken up with extra fuel capacity, but the insulation may be worth the cost difference considering being in SE AK for 5+ months on the water......time will tell I suppose, I will put that on hold for now and find some other issues to bug you guys about.. It is my understanding that these boats are lined with foam insulation and covered with marine vinyl, have there been any know cases of any seperation of the components, sagging vinyl, loose foam and such?

[thataway]

[Marco Flamingo]