I'm thinking I might actually paint my bus next year. My bus is all aluminum with fiberglass front and rear. The clear coating is peeling in spots so I plan to sand at least some of the paint. What grit sandpaper would I start with for aluminum? For stripping a car they usually recommend 36 grit, but that seems a bit coarse to me for aluminum.
I'd start with 80 grit. Then 220 then 320. Good Luck, TomC
Are you thinking to strip the paint off down to the bare aluminium, or surface scuff the paint? I would do almost anything to only surface scuff the paint, so that you don't have to replace the factory undercoat and acid wash later. I would use maybe 200 grit and do it by hand, after cleaning with wax remover and reducer. the fiberglass is a different thing altogether, there I would tend to go down to the glass and rebuild it up. I have had good luck with cracks by grinding out the crack down to the fiberglass and filling with a slurry of resin mixed with micro-bubble fairing filler. Anytime you need to bond to fiberglass you need to grind with 80 grit to get teeth in the surface.
Brian
I'm not really sure how far down I need to go with the paint. None of the paint is actually peeling other than the clear coat. The paint is three different colors and I definitely need to at least remove the transitions between the colors. It looks like they painted white first and then painted green and gold on top. There is a definite ridge where the top colors end.
I used Alcuobond panels to cover my windows and those will need to be primed for sure.
I agree with TomC, I would use 220 and then go to 320. using a DA sander. Good luck
I have a Dewalt 5" diameter palm rotary sander that I swear by. You'd be surprised at how fast 220 will take anything off. Good luck, TomC
Interesting on the 220 grit. I used 80 grit on my roof with a 1/4 sheet palm sander to prep before applying the elastomeric. Only in a couple spots did I end up taking all the paint off. I suppose I really don't want to take all the paint off anyhow.
I just did mine. I used 220 with round palm sander. Just nock the shine off till you have a dull finish then you are ready for some GOOD primer. Then I used a single stage paint. No need for clear coat. $1500 in materials.