Spray painting the edge of routed ACM before applying vinyl?

Krylon Fusion works well for this. We've done it many times. If you are spraying an inch or two onto the face it needs a light scuff with a scotchbrite pad.

 

Overnight should be good, The solvents in Krylon are pretty "hot" so they evaporate pretty quick. I don't use a primer. A test piece is always the safest way to proceed.

 

We do the same, works fine

 

If you mask the graphic before you install it you can paint after installation and then peel the mask. When you do it this way you can trim against the ACM and don't have to worry about scraping the paint.

Typically signs like this aren't inexpensive and it's worth it to use a cast vinyl and lam. If the vinyl and or lam shrink over time it will create a bad impression.

 

P.S

The difference between the cost of cast vs. quality calendared vinyl is minor, especially compared to your labor or your reputation.