Hello all,
I am starting to get my ducks in a row for my big upcoming spring painting project and needing some good sound advice which I can always count on you guy's. I talked to my local marine parts store about my paint issues "checking" and their advice was to go ahead and strip the old paint off. They said to go to my local auto parts store and purchase a product called Aircraft paint stripping? He said you roll it on let sit for a period of time and take a puddy knife and remove the bubbled up paint. Just a side note I am painting the flat surfaces above water line. Or should I sand with 220 grit? I will be posting pictures tonight so you can get a better idea of what my current paint looks like.
Thanks,
Rob

Stripping didn't work for me. I tried it on a small area. Somebody recommended some miracle remover. It melted and bubbled the paint alright. But you have to be there to scrape it at the optimum time and work fast because it just hardens right back on. It was a mess and I still had to sand.

I have two boats and two different paint problems. One has several coats of who knows what and the other has the original factory paint. I took the most conservative approach with the boat with factory paint. First I sent my paint, the flybridge and the side cowls out to professional auto painters. These pieces have the trim stripes. They did a great job. Then I sanded the decks and cabin sides starting with 80 and ended with 120/150. I had a lot of spiderweb like checking and a lot of "pinholes". I tried to sand past the rotten paint keeping the brown undercoat wherever possible. You have a lot of filler under that paint. Where it was sound I left it. Where It broke out I filled it with an epoxy compound. In some spots I sanded all the rotten paint off and still had pinholes and cracks. Here I used a polyester finishing putty, Evercoat Easy Sand. It worked great. Dries in 20 minutes and has built in etchant. Unfortunately I have to sand and reapply the topcoat because I left it out without cover over the winter. That was just like putting it underwater (DUH!) and the paint bubbled up on the horizontal surfaces.

The boat with multiple coats will require more horse power. I got a UNI-RAM sandblaster on EBAY. It has a vacum that recycles the media and you don't need a moonsuit to run it. I don't have a compressor which will drive it so I will have to buy or rent one. Any compressor which will run the blaster will also run air sanders. This boat could also use a bottom job. I only needed electric sanders for the boat with the factory paint.

And a reminder, that any place where you cut thru top bare metal has to be properly ethed and primed before overcoating. And, another reminder that bare aluminum must be treated (coated) with hours of being bared. Not days, not overnight -- 4-6 hours -- or the paint won't stick. One coat will then allow you all the time you need to go to the next step.

You can get epoxy to stick to bare aluminum if you put some on a piece of sandpaper, and wet sand it into the surface. You sand off the oxide and coat it before it can oxidize again. Works great with WEST epoxy, don't know about others.

I have done the same but used a stainless wire brush instead of sandpaper. That works too. Otherwise, I would etch it even for epoxy: the problem is that the oxide layer that forms comes right off, and your epoxy with it. If you drag your finger across a piece of bare aluminum, you get a black mark on your skin. That is oxide.