Had trouble with paint sticking on the last front lip I painted...I've done a decent bit of research and haven't found a really good way to prep a new urethane lip for paint. I don't know if I still had some mold release agent on there or what.

Tips and specific products used would help.

Thanks in advance.

 

Visually inspect the part for flaws.

Wash with hot soapy water.

If you can, bake the part, then wash again.

Wax/degrease.

Abrade.

Wax/degrease, then let it sit for a few minutes.

Wipe with a water based prep cleaner.

Test virgin solvent or MEK on a non visible area. If OK wipe with the selected solvent once the part is ready in the booth/ready for a tack rag. Let it sit for a few minutes then tack and apply adhesion promoter. Or skip this step if the solvent harms the substrate,(and I would be very suspicious if flexible urethane is effected). The strong solvent will dry the surface and should accept the paint well.

Use a quality paint line, and refer to the data sheet for each product. Use adhesion promoter then a sealer, then base.

 

what I simply do with all bumpers before painting, is wet sand with 600grit paper, let it all dry, clean with wax & grease remover/surface cleaner, spray some paint addhessive(Bulldog) as well as add a little to the paint itself so that it has some flex, then paint.