Blister Repair and Bottom Paint

[wheresbob]

I continue reading and learning more everyday from this forum. I've got a bottomside question. I don't exactly understand the layers I've exposed on my hull and I'm not exactly sure how to proceed...was hoping you guys could lend some more sage advise :o

I plan to sand and fill the blisters that formed (before I bought the boat) on the port side hull and then take the boat to the professional painter for new, properly applied paint layers. My question is: Do I need to do more than sand the smooth pinkish layer? The concave pock marks will get filled, it's the smooth areas I don't know if anything should be done with or if the painter will handle it all (with an eppoxy barrier, for example)? Thanks in advance for your thoughts, and feel free to make fun of my ignorance! :o

[Bergalia]

First off Bob, we Scots always recommend woad as a bottom paint (see Braveheart)....

But from your very useful illustration I seems that you've got the right idea already. I take it that where you cut the blisters down there is still enough strength in the skin. A 'flexible' layer of filler - smoothed down, then covered with a resin should suffice. (Glass experts will weigh in later - so listen to them). Finally I'd give a light sanding overall to give a 'key' to the final coats.
Good luck.

[wheresbob]

Thanks Bergalia -
Glad to hear I may be on the right track - just hacking through it here. Wasn't sure what you meant by a light sanding to give a 'key' to the final coats? jt

PS - And I like to put woad on, too, but only on my neck and knees and where I sit on.

[Bergalia]

A light sanding - roughen the surface to allow the final coat - paint or gel - something to grip. Painting on a smooth surface is seldom satisfactory so a light sanding/scouring improves the adhesion.:)

[lazeyjack]

ok here comes the expert Bergs wuz talking abt:))
make sure the boat is DRY, finish the making good, really use 100 grit to establish your key, then 75 microns wet film thickness, 2o1 devoe(this sticks to (unknown surface) then 300 microns DFT number one devoe epoxy or SIMILAR, then BEFORE it gets hard, like so you can still mark with your thumbnail(use fingure if you have no thumbs) apply your antifoul
25microns is one thou, buy a wet film gauge, (plastic disposable) we use a nice ss one, which is guarded jealously, have fun

[tja]

Sand the bottom with 80 grit. Areas that need to be filled, use epoxy thinkened with micro baloons. Sand repaired areas to finish. Coat bottom with Interlux 2000- 2001 moisture barrior 5 to 6 coats. Then 2 coats VC17 antifouling. If you are able to do the repaires and prep the bottom then you can do the whole job ans save yourself the cost of paying someone else.
It isn't that hard if you plan it out well. Make sure that the surface is dryed completely before you make any repaires or apply any coatings. If the boat has been inside for some time that will be a plus. Preperation is 99 percent of the job. Good luck. Tom.

[nero]

Micro baloons below the water line? Thought it was coloidal silica for that.

[lazeyjack]

Micro baloons below the water line? Thought it was coloidal silica for that.

tim you can use micro, BUT then you must paint as per what I said, Micro is all we use down here from 1o dollar models to 100 mill yachts

[wheresbob]

Thanks everyone. I’m making progress then, having sanded the bottom of hull with 80 grit, and now I’m ready to fill in the blister pock marks. I’m a back yard hack, but I’m determined to make this boat right again (all 14’ feet of her!) and I appreciate everyone’s input and the forum because I’m learning enough to be dangerous! Thanks again. jt

[lazeyjack]

Thanks everyone. I’m making progress then, having sanded the bottom of hull with 80 grit, and now I’m ready to fill in the blister pock marks. I’m a back yard hack, but I’m determined to make this boat right again (all 14’ feet of her!) and I appreciate everyone’s input and the forum because I’m learning enough to be dangerous! Thanks again. jt

bob you made me larf, I thought you were talkin about an in the water megayacht!!