PoorInRichfield

On my last custom frame paint project for a steal frame, I used a metal primer + color + 2k clear and let the paint dry for several days between each paint type (i.e., painted primer, let it dry for a few days. Painted color, let it dry for a few days. Then painted 2K clear and let it dry for a few days before polishing it.) I originally thought it was necessary to allow each layer to dry thoroughly, however, I noticed that the finished product, while it looked good, still chipped pretty easily.

I later read that one shouldn't allow the paint to cure completely between each layer. I.e., applying a color layer an hour or so after the primer and the 2K clear an hour or so after the color will allow the different layers to chemically bond to each other, creating a more durable finish. Perhaps the 3rd option is to let each paint layer dry for a few days and light sand between each layer, but that sounds like a lot more work.

I'm about to paint another frame and I'm considering trying the latter technique of not letting each paint layer dry for more than an hour or so in hopes of having a more durable finish in the end. Thoughts?

Sample from my previous custom paint job...

guy153

My (very limited) understanding is that colour layers that are all 1k should be reapplied either when not completely dry, like after half an hour or so, or when totally dry, like a few days, but nothing in between. If putting a 2k clear on, wait for it to fully dry, because the 2k will seal it all in and may prevent it drying. If the colour layers are also 2k then probably it can all go on with short intervals. But I really don't have much clue so am just putting this out there in the hope people will correct it.

Andrew R Stewart 

Every paint formulation I have used for bikes had its own recoat time. Many are like guy says, suggesting a recoat after set up but before fully dry or after fully dry (and then a fine wet/dry sanding can help adhesion IME). Also, as he mentions, applying a top coat that cures/dries quicker than the under layers do could lead to issues as the under layers are still wanting to off gas.

However some paints suggest only short recoat times. The, new kind to me, clear (and hardener) I just picked up mentions only about 10-15 minutes between coats and nothing about longer amounts of time between coats. Andy

squirtdad

IME most paint products have recoat times listed....and temp ranges for painting, that is what I followed.

what type of paint are you using for color? real automotive paint is much more durable than auto store/home depot rattlecan