Finishing routed edge of MDF

The Artful Codger | Posted in Peter Gedrys on July 24, 2006 11:14am

We’re still putting the house back together after being flooded by Hurricane Ivan almost two years ago. I’m trying to stretch the insurance money as far as I can. The original baseboards (480 linear feet) were pine 1×6’s. I’d like to save some money by using MDF. I let my wife see a sample with a routed Roman ogee, which she likes. She’s doing the finishing and planning to paint them white over a primer. The problem is that the routed surface gets fuzzy when the primer is applied and is difficult to sand because of the shape.

Would an oil-based primer and paint work better than the water-based she was using? Could it be that my router bit is dull? Is there some other way we can avoid raising the “grain” of the MDF?

Thanks for any advice.

Replies

The Artful Codger | Jul 24, 2006 11:17pm | #1

This was supposed to go to ALL --

We're still putting the house back together after being flooded by Hurricane Ivan almost two years ago. I'm trying to stretch the insurance money as far as I can. The original baseboards (480 linear feet) were pine 1x6's. I'd like to save some money by using MDF. I let my wife see a sample with a routed Roman ogee, which she likes. She's doing the finishing and planning to paint them white over a primer. The problem is that the routed surface gets fuzzy when the primer is applied and is difficult to sand because of the shape.

Would an oil-based primer and paint work better than the water-based she was using? Could it be that my router bit is dull? Is there some other way we can avoid raising the "grain" of the MDF?

Thanks for any advice.

bruce277 | Jul 24, 2006 11:41pm | #2
Artful,

IMHO, the fact thet you're using a water-based paint, is the reason you're having raised grain.

This is similar to using water based dye. Usually, you spray the stock slightly wait till the grain raises and sand it. Because you're using a profiled edge, this makes the job extremely difficult and time consuming.

Try a test using the same stock, scrap MDF and any similar oil-based paint, make sure its the same brand. I bet it will work.

Best Bruce

The Artful Codger | Jul 25, 2006 02:18am | #3
That was my guess. I'll let you know how the oil-based paint works.

I have a .22 rifle that I refinished the stock on by wetting, steaming, and sanding with 400-grit paper, going through the cycle until the grain wouldn't raise any more, maybe a dozen times. Then I oiled it. It's still slick as glass.

Thanks for the help.