yiffzer

Hey all,

I'm new to painting and am at the moment refreshing a Cannondale SR frame with a brand new hammered copper color. At this point, the final top coat (fourth layer) is drying. The clear coat will occur next. I'll be using UPOL's #1 Clear paint to apply the clear coat. Their technical data is here: https://images.myautoproducts.com/ima...UP0796_TDS.pdf. However, my confusion stems from being required to sand it before applying the clear coat. My concern is that I've seen what 1500 grit sanding does to the paint. It leaves a rather terrible spotty mark that is irreparable even with water sprayed over the area. I'm unsure how clear coat would restore the original top coat sheen. At this time, I feel that it's best to just let the top coat dry, scrub it with terry cloth to gently "roughen" the surface, apply decals, and then clear coat it.

Anyone who has done clear coating on a bike, please confirm whether I should really be sanding the paint down or is letting it dry sufficient?

obed7

I am not a paining expert, but I have painted a few bikes for fun. I did as the instructions show and it worked fine.
After completing the clear coat. I actually did 3 coats of clear, I used polishing compound and the finish looks deep, like you are looking into a pool.

dsaul

The instructions say to "abrade solid colored base coats". A hammered finish is not a solid color and I would not sand it. The clear should be applied before the base has completely cured, in order to obtain a chemical bond to the base. The instructions say to apply within 20 minutes over solvent based base coats. I would do a test piece before spraying it on your frame, to see how the clear affects the hammered finish.

02Giant 

What was the hammertone finish application process?

yiffzer

Technical data sheet: https://www.rustoleum.com/~/media/Di...Brush_TDS.ashx. That's been done -- applied two coats maximum separated by approximately 30 min. I've done four coats so far in total in roughly one week and a half.

So it sounds like to me... once it's dry in roughly a week, I should sand the surface lightly, do a final [light] coat of top coat, and then add clear on top within a few minutes. Flash off for 5-10 minutes, then do the second, medium coat of clear. Leave as is. From there, I will apply the decal. One thing I'm not clear is how long we wait for the clear to cure before re-applying another clear coat to seal in all decals.

easyupbug 

+1 in general, but it would be worth checking with the paint manufacturer if in doubt. I have used several automotive two part Urethane systems as well as typical enamels and abrading was not recommended for anything other than a solid color base coats.