Painting MDF

[TurtleCove]

My friend wants to paint some carvings I made out of MDF.
She will be using acrylic paints, not ink.
I'm concerned about the paint absorbing into the fibers, and looking poor.
I was thinking perhaps she should spray the board with a sanding sealer first, and then paint on top of that.
Thoughts?

[chebytrk]

Correct. That's what I do. I use sanding sealer so there is no "bleed" thru. Sometimes after sealer I'll re-sand a little and seal once more. After that I paint and all is good.

[lawrence]

yep, you nailed it- seal, then paint. (priming first with an oil based primer helps too)

I like shellac as a sealer

Lawrence

[Proctorw]

What brand or brands of Sanding Sealer is recommended? I need to sand some "fuzzies" and then I will be painting/staining some signs made of pine.

[Ton80]

I recently posted a topic on this and you can search it out but same basic advice was given. I experimented a bit and used a Latex primer, ModgePodge, and white glue. All seamed to work fine but I ended up using the Latex primer because it gave me a white base to paint on. You probably won't remove all the texture of carved MDF but you can definitely get good results if you are going to paint it. I didn't try the oil-based primer because I couldn't find it in a quart size and I wasn't spending the money on a gallon to buy the ounce that I actually needed for the test. I also didn't try the shellac because my local supplier had stuff that was well over 3 years old sitting on his shelves and it's all expired!

If you are going to stain - no sanding sealer until you have stained unless you're using a gel stain ;) Same goes with just about any sealer you would apply. Any type of absorbing stain ( minwax for the best known ) has to soak into the wood and a sealer will prevent this from happening.

[RobertP]

I use high fill automotive primer on all of my MDF projects, the stuff is great once it sets up, then it can be sanded as smooth as you want it

[mtylerfl]

I use high fill automotive primer on all of my MDF projects, the stuff is great once it sets up, then it can be sanded as smooth as you want it

Hi Robert,

Do you have a brand/name/type of the particular auto primer you use? ...and where it can be purchased (AutoZone, Pep Boys, whatever).

I used to use a Dupont-brand auto primer back in the day when I was scratch building radio control planes. I don't recall which one of the Dupont primers though. I used it for prepping fiberglassed foamcore wings. For that application, you sanded ALL of the primer off when dry...it only stayed in the "dips and crevices" and acted as a filler. Yielded a really nice, smooth surface for final painting.

[RobertP]

Here is what I use, you can get it pretty much any hardware store.

64516

[mtylerfl]

Thank you! That will be easy to find, sure enough!

[unitedcases]

Going to bump this one...for the edges of mdf, sanding sealer or latex primer as well?

[RobertP]

I use autobody glazing putty. I have also used drywall compound.

[unitedcases]

Need to be able to spray. Doing some cutouts in the shape of afghanistan.

[unitedcases]

I was thinking of using the white kilz primer sealer spray. I need a white base and all I am going to do after that is gloss it and lay a piece of vinyl on it and regloss it. Thoughts???

[RobertP]

What are going to use for your clear?

[unitedcases]

Got plenty of clear poly on hand. Probably just go with that.

[RobertP]

That should work, I would try a test piece to make sure you don't get any yellowing from the kilz, I had that happen once