"butter board" finishing

I’m in the process of making a final model for a college project. I chose to use butter board (poress urethane foam) as its fairly curvy form which would have a been a pain to do with renshape, my prefered material.

I got the form mostly roughed out and am working on smaller details like button, etc, however I’m a bit hesitant about finishing this foam.

I was thinking I’d have to skim the model with a light bondo or joint compound however someone claimed to have finished butterboard with multiple coats of primer.

Whats the easiest way to go about this yet retain a very clean surface to paint?


i would say take some scrap and try each method you said and see what looks the best. maybe a latex spray paint? if your worried about paint eating it…will the heat of the bondo cause deformation? gotta test it out on scraps.

its not nearly as fragile as blue foam type materials. I know you can srap paint right onto it and bondo which I’m going to have to do atleast a bit to add fillets and blend some of the forms together.

  1. sand raw foam to 400 grt
  2. 1 coat high build primer (or 5 coats standard sandable primer)
  3. sand with 400 grt (wet sand optional but prefered)
  4. 1 light coat primer
  5. sand with 600 grt (wet sand prefered but optional)
  6. Final color coat

Key is to let dry completely between coats, and use the same brand paint start to finish.

cool, thanks, that was roughly what I had in plan, perhaps if I can find an automotive paint place in boston I can pick up some “real” filler primer to save some time.

autozone has it…(or they used to anyway)

I think the one next to coolidge corner is the closest if your at massart

oppps…packards corner