Blisters

[Hull376]

I know blistering hasn't been much of problem with Ariels/Commanders, or so Bill's manual says. But here's my experience. I've been re-doing 376 for the past year. I stripped off all the accumulated bottom paint and looked closely at the gel coat. I saw some very fine cracks, mostly on the keel as it angles up to the bow. I got out the grinder to "investigate" and see how deep they went, and did find some evidence of blisters as I removed gel coat. There were a few spots where the laminate had some pock marks-- clearly where the resin had dissolved. It wasn't too bad, was restricted to only a few areas. The fix was to remove some of the gel coat and then coat the bottom with several coats of vinylester (supposedly seals better than epoxy--- we'll see). Got a nice finish. Just because you don't see anything obvious doesn't mean something isn't going on!

[Tony G]

Kent,
Wow! That's eye candy. New topsides Too?
Tony G

[Hull376]

Oh yea!

[ebb]

Incredibily FAIR topsides. I hope 338 ends up like that!

Have you any photos of the bad stuff in the turn of the keel?

[Hull376]

Ebb,

Picture you requested. This is about a foot long section of the keel right where it curves toward the bow. None of the pitting was evident at the surface--- just some very faint spider cracks. The grinder revealed these sinister pin holes. The vinylester filled it in nicely- I put on about 5 coats with a roller. The hull was completely dry.

[ebb]

Capt Kent,
I guess we've learned that spider cracks are a gelcoat phenonmenon. The pinholes could possibly have been made by the sputtering of the gelcoat gun.

You were satisfied that the rather LARGE pinholes did not go very deep? Ob viously.

338 has had some gelcoat removed but not in that area - going to sherlock with a clean glass soon as I get down there again! Sounds like it is right in front of where the lead keel ends. Can't be significant. And you are past all that!!!!

[ebb]

338 has similar pocks.
Where we removed the gelcoat the mat looks absolutely solid.
IMCO it was a manufacturing phenomenon.

BUT in talking with the yard guy here, who has a Triton and plenty of local knowledge about them, blisters are not uncommon in Triton hulls but never in any quantity. He pointed out that that uncoated bilge where there is constant water is the culprit. Can imagine that the polyester hull from the waterline on down has water in it. And the bilge constantly. 338 was diagnosed by the surveyor with a few blisters, but they disappeared by the time the bottom was stripped.

Can also imagine that spraying gelcoat into the onepiece mold and following with mat in the tight areas of the keel and bilge was problematic to say the least. Where the gelcoat and mat meet that is revealed in our grinding the surface is uneven and pobbled. I think it must have been a toxic nightmare getting these hulls laminated 40 years ago.

It looks like A/Cs are pretty lucky in the underwater gelcoat department.
Has anybody else had blisters?


I pryed a large abalone sized piece of primative bondo off the bottom of 338. It bared the mat and roving that had not been pressed down sufficiently into the nold. 338's rudder shoe when taken off revealed that it was held on by one pin, because the heel was mostly crystalized poly because the fabric had not been poked down in.

[marymandara]

On Triton 397, we have dealt with several hundred of those little pockmarks.
I knocked off the old bottom paint and smoothed out the hull using my beloved 7" vertical polisher (thanks, Uniflite!) and a DA with a 6" pad...all this with 60 grit. Found that just as Bill suggests, the gelcoat was thinner in the aft end of the keel, although the pinholes were prevalent everywhere...looks like the outer layer of roving did not get wetted thoroughly enough. lost of little thin "scratches" about 3/8" long proved to be the top of a pinhole when pushed on with a screwdriver...so they all got chipped open, too.
I also found a couple of significant blisters in the process that were not visible or notably protruding under the paint---mainly in the area of the ballast cavity, which contained a significant amount of water!
Dave

[skylark]

Some friends of mine owned Commander number 25, which had severe blistering on the starboard topsides. When they sold it, they had the problem fixed at quite a cost. I owned Commander #216 for quite a few years and never had any problems.