SeaCraft 20 '74 hull, post soda, now I...

[cmoore]

...have many blisters removed and after drying (how long should it dry?) I plan to fill in the holes where the gelcoat is missing and I'm looking for sage advise.

Thinking of using Epiglass epoxy resin as described in the Interlux Interprotect Pro Bulletin. The picture also has an example of a large area of missing gelcoat. I see ~20 of those and will address those one way but I have ~1,000 of these pencil eraser head size holes. What suggestions do folks have?

I plan to eventually apply Interlux Interprotect 2000 and Micron Extra on top of that.
Thanks

[Islandtrader]

Those really aren't blisters per se. When I had my hull blasted it looked the same way. What that is is a void under the gel coat. I just used epoxy filler and the faired them out. Put a barrier coat on then primed and painted.

Check out post # 28 and 86 on my rebuild thread...the picture shows my hull looking the same and what it looked like after putting on the protect.

[flyingfrizzle]

I agree with Islandtrader on this one, There may be some blisters but yours looks like air bubbles in the lay up when they glassed the hull in the mold. The gel hides most of that stuff if they don't roll the air bubbles out well but they will show up one day. The give away is the amount of them in the step area. That area is prone to getting air in it when laying up due to the curves. They appear uniform down that step area. Most blisters bubble outward cause the moisture swells the fibers and will be spongy. They may of made it easier for water to get into the fibers so check it well but you may be lucky and not have much damage. I would check down the notched areas on each step. You probably will find the most of them in those areas. Epiglass epoxy resin is good stuff be man it is expensive. Any epoxy based product will work well. I use the interlux watertight epoxy filler and have good luck with it doing what you are trying to do. It is thinner than most fillers and goes in the small spots well, almost like a glaze. It will fill easier and hold better if you tapper and feather the holes out some before applying.

[cmoore]

...about 12 in prep and another 8 in painting. Both responses above were right on. With only one exception all failed areas were dry.

After soda blasting I washed the hull with vinegar, water and a stiff brush. I then used Interlux Watertite (longer cure) which needs to be ordered as no one stocks it applying that on damaged areas that would be seen and over the transom area where a prior depth finder caused damage. For the other damaged areas I use West Marine putty and I used that as a final skim. I really adhered to cleaning before applying filler.

Think I filled 80-90% of the over 1,000 damaged areas passing on small stuff. I chipped away on most all cracked gelcoat. I probably could have done a lot less but just could not resist. The sanding was a major effort and Friday ended when I just could not hold the sander up anymore. Did the final wash down, brush and rinse (hull dried more quickly than expected). Spent 10hrs Friday and 2hrs Saturday.

Applied 2 coats of Interlux Interprotect 2000 and one coat of Interlux Micron Extra in an afternoon. Came back 18 hours (and many ibu's) later I applied a second coat of Micron Extra. Spent 7hrs Saturday and 1 hr on Sunday.

A gallon of Interprotect was too much for 2 coats on a SC20. If I had more energy I'd have done a third coat (and still would have had extra). If you use this great stuff I suggest you think through the mixing and containers on paper first. And I was lucky with the weather. Temps in the upper 60's and humidity in the low 50's.

Once on the trailer I will sand and Interprotect the areas under the stands with their second coat and apply Micron Extra to that area and apply a third coat to the bow, transom, etc...

After 41 years it was time for this butt lift. I will take more close up photos and compare them at the end of the season to see the real results of time and use.