Join Date: Jul 2008
Location: Hershey, PA / Middle River MD
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Bottom Paint Questions
I’m about 45% done removing the bottom paint off my new (used) 1981 Islander 30. I read a lot about it before I started but I’m stilling learning.
Under the bottom paint is a 5 coat West System barrier coat. About 20% of the paint was easy to remove with a scraper – almost flaked off due to poor adhesion. Another 30% was removed with a scraper with a lot of work. The rest is coming off with a random orbital sander using 80 grit paper. I’m about 20% done with that – it’s brutal. When I’m done sanding, I plan to apply two additional barrier coats.
I have several questions:
1. Do I need to remove ALL paint? There are some depressions or pits (small veins and depressions) that are holding a small amount of paint. Removing that paint will mean removing 1, 2, or 3 layers of barrier coat. Could/should I use chemical to remove the paint from some of these pits?
2. How to deal with thru hulls and screens.
3. There are several areas (bow and rudder) that have some previous repair filler. From the way it sands, it appears to be a fairly soft filler material. Should I glass over this before applying my new barrier coat?
4. What is the best way to sand the bottom of the keel? The 6” radius between the keel and the bottom?
5. What is the best way to sand but not too aggressively, the leading and trailing edges of the keel, rudder, and hull?
6. How to deal with the boot stripe. The barrier coat meets the boot stripe. The bottom paint overlaps the gel coat. I’m sanding the bottom paint off the both and trying hard not to damage the gel coat.
7. What causes bottom paint to flake off? I have looked at numerous boats in the marina. Most have cracks in the paint where the initial, of several layers, of paint have not adhered to the underlying surface. I had a lot of this – probably because the boat had been out of the water for 3 consecutive seasons. When I apply my first coat of bottom paint, I want to ENSURE it is going to have 100% adhesion over the entire bottom and that it will last. How can I best assure this happens?
I know this is a lot. Answers to any one or two items would be appreciated.