[justCNCit]

Hi, I was thinking of making a few parts out of MDF for my machine. However, it would be really nice if I could paint them, both for cosmetic and function. I was thinking of using acrylic to smooth out the surface and make it more like a plastic.

Since this stuff seems to absorb moisture, are there any suggestions out there? thanks.

[mcphill]

You need to seal it first, and it sucks up paint like a sponge. Coat with Binz or Kilz first to close off the pores, then primer and finally topcoat.

[CarveOne]

Hi, I was thinking of making a few parts out of MDF for my machine. However, it would be really nice if I could paint them, both for cosmetic and function. I was thinking of using acrylic to smooth out the surface and make it more like a plastic.

Since this stuff seems to absorb moisture, are there any suggestions out there? thanks.

I would recommend a coat or two of Kilz brand oil based white primer first. It has no water in it that would cause the MDF to swell up and get knarly looking. It is very smelly stuff though. Then you can use oil base paint over it, or use latex base paint. Oil base primer will withstand water in the latex paint long enough for the latex to dry.

When I paneled my work shop walls with sheets of 7/16" OSB I searched for painting contractor forums with recommendations for painting OSB. Oil base primer first, then latex paint final coats. Just to be sure, I used two coats of oil base primer. The flakes of wood on the surface of the OSB laid flat and didn't curl up.

CarveOne