Blistering

[Quetzalsailor]

I'm sittin' here on Quetzal, on the hard, absolutely dawg tired having sanded, masked and painted the boottop. I think the boottop and hull are painted with Awlgrip. Normal floating height leaves the boottop about 2 1/2" out of water. Wakes and chop wet the boottop enough to grow stuff, particularly on the habitually west-facing side of the hull.

The boottop was badly blistered and some areas had peeled. Paint failure was of three types: blisters where the separation was between the 'under-stuff' and the Awlgrip; incipient peel at burst blisters and at scratches; blisters where the separation was under the under-stuff. The understuff appears to be a thick layer of some sort of filler or sanding primer. More annoying is that the blue Awlgrip above has some of the same sort of blistering, but no peeling at scratches. The deeper, under the 'under-stuff', blisters are not gooey or smelly but they do apparently ooze something; there is occasionally staining.

The bottom shows maybe two or three (total!) possible blisters or weeping. The weeping places are not large nor blistering per se. The bottom was once upon a time sandblasted and coated with some sort of gooey, soft barrier coat.

So! Can you really have osmotic blistering above the waterline? As much as 8" above the waterline?

I plan to paint the bottom tomorrow and have the boat splashed for the season, but I might as well fret about upcoming repair procedures. I suppose the 'gold plated' cure would be to have the whole hull peeled and laminated in vinyl ester, faired, Awlgripped above and bottom painted below. I'd have the ballast keel glassed to the hull to obviate further fretting about the keelbolts that are encapsulated in the bottom of the watertank, too.

That's it, I quit! I've had my G & T and I'm off to a shower, dinner, and the sights and sounds of cosmopolitan Rock Hall!

[Chris Campbell]

Art Karpf has said that the early NE 38's had some trouble with porous gelcoat which resulted in some blistering, but that the later boats haven't had anything worth noticing, and that even the early boats were spot-repairable. Of course everyone has their own opinion about blisters, I've only got mine, and the ones that I've heard that I agree with, so take with the proverbial grain of salt.

Weatherbird had been peeled and resurfaced due to the previous owner worrying about blistering - she did have a lovely bottom as a result, but I expect that it would have been just as nice with spot repair - and probably stronger. Removing and replacing laminate can't ever be as strong as the original, since there is no hope of a primary bond anymore, so to keep the strength it'd need to be thicker (and heavier, although I don't know how much difference that would make in the overall scheme of things).

Weatherbird also had some topsides blisters - but they were tiny - maybe 1/16"-1/8" at the largest, and just in the paint layers. Speculation amongst those I discussed it with was that it was due to the topcoat going on too soon over the primer - after the repaint they didn't return, so it was probably the case.

At any rate, my opinion would be to gouge 'em out, fill with appropriate filler (underwater or topsides), and repaint. I'm with the majority on this forum on the usefulness of barrier coat, and wouldn't use it.

How did your bootstripe come out? Does it look nice despite the surface you had when you started?

[Quetzalsailor]

One coat, brush painted, Brightside Polyurethane. Certainly not wonderful but lots better.

[Chris Campbell]

She looks smashing!