epoxy resin weeping inside. Delamination?

[matt1]

We have had our 1966 A-30 since summer. We are on the Gulf Coast, so our nights and days have a significant temperature change in Winter. When the first cold nights came on, I would go to the boat some mornings and see condensation on the roof of the cabin. As the nights got colder, and the daytime temp stayed mild, I started to note some mildew growth on the cabin top. I cleaned with a bleach spray, and meant to install a dehumidifier, but the boat yard we are in does not have power to the docks. We were waiting for the channel to our permanent slip to be dredged. I had to leave the boat for about a month uninspected, and when I returned, not only was the mildew back, but resin is weeping from the cabin top from the moisture. There are small pockets of resin under the paint. This is only in the cabin top, and mostly confined to the places where the condensation pools from gravity. My question is "if this sort of osmosis takes affect, will drying out the boat stop the problem, or is this a chain reaction kind of thing"?
Fair winds,
Matt

[Rachel]

I've noticed something that might be like what you're describing on various boats. That is, when condensation forms inside the boat, sometimes the hanging drips will be tobacco-colored. I've not seen it as "blistering" behind the paint though -- it was just on the surface. And not always on boats with wet core, or that were smoking dens, either.

I'm interested to read what people make of this.

Rachel

[Figment]

The paint is blistering because of the moisture. It's not resin, it's just watery paint goo. Drying out the boat will solve the problem. Ventilate the boat, and the blisters will heal themselves.

[matt1]

The drips are in fact tobacco colored, as are the contents of the blisters. It is puzzling, as the drips and pockets don't have that acrid smell that you normally encounter with resin pockets. I restored a 70's macgregor some years back, and I had to do the whole job on blisters in the hull, but these smelled really strong. However, they are visually the same, and both have a tacky feel. Hopefully it is something in the paint, however, the paint is white... Have you had any luck with the absorbant buckets of stuff from West? We are looking at about a month til we will be at a dock with power, and don't feel comfortable leaving a hatch open to ventilate.
Thanks

[Quetzalsailor]

On our M 27, I had reddish goo weeping out of cracks between the fiberglass overhead and deck, where they met around the ports; from around bolts that passed through the deck, the liner and into the interior; and behind the vinyl hull liner. The stuff smelled vaguely like styrene plastic (you know, like new model cars). Some of these deposits were quite big, say drips 3/32" thick. This, on a boat that was, by then, 24 years old. I scrubbed the stuff off using soap and water, then lacquer thinner. There was no recurrence in the 8 further years we had the boat. I decided that the stuff was probably excess catalyst out of the polyester (isn't that one of the suspects for causing blistering problems below the waterline?), and that most of the stuff willing to migrate had done so. (The boat had had a few blisters early in its life, none for years and years, but minor tiny pimples along the waterline at 30+ years, so the resins were apparently pretty good.)

What's the construction of the overhead in an A-30? If there are wood strips glued to the underside of the deck, and some sort of hardboard ceiling screwed to the strips (like our NE 38) then there's plenty of water-soluble stuff in the wood to turn water a dirty tan.

[Rachel]

On a 1966, the deck and coach roof of an A-30 would be composed of fiberglass-Masonite-fiberglass (or wait, there might have been two layers of Masonite with another fiberglass layer in between, but same concept for this purpose). The Masonite is like pegboard, in that it has a regular hole pattern.

A-30s with this type of deck rarely seem to have core issues. Perhaps because the Masonite has a lot of "glue" in it? There are a series of default resin "plugs" in the holes?

Edited to add: There is no overhead liner - of wood or fiberglass - in the A-30. It's just faired fiberglass that is the actual lower surface of the deck sandwich.

Note: The tobacco drips I've seen have been on various types of boats. Perhaps even in some non-cored areas, so perhaps it is the "excess styrene" that you mention...?

Rachel

[matt1]

I dried the boat out, and left it for a couple of days, and don't see any evidence that it is continuing to happen. I guess that the solution is to not let the condensation form in the first place. The pocks that I had punctured were totally dry. Some of the others were still plyable, but notably less. Now lets see if the cabin top starts to rain paint chips where the pockets were.
Thanks all,
Matt