MDF edges?

[reible]

Hi,

I have a project to do that will require some MDF to be painted. In the past I have mixed glue and water and painted that on the edges, let it dry then light sanding and primer.

Since I no longer get many new woodworking magazines I wonder what if anything is the current thinking on doing the edges. I've done shellac but it seems to take more coats...

The pieces are going in a house with zero wood trim and will be near a mantel and flat screen TV so they will have to "blend" into the situation... I was however thinking of just a bit darker color for the edge to give it some depth (shadow effect) but very lightly so. Any thoughts on that?

Ed

[a1gutterman]

Hi,

I have a project to do that will require some MDF to be painted. In the past I have mixed glue and water and painted that on the edges, let it dry then light sanding and primer.

Since I no longer get many new woodworking magazines I wonder what if anything is the current thinking on doing the edges. I've done shellac but it seems to take more coats...

The pieces are going in a house with zero wood trim and will be near a mantel and flat screen TV so they will have to "blend" into the situation... I was however thinking of just a bit darker color for the edge to give it some depth (shadow effect) but very lightly so. Any thoughts on that?

EdI know that my wife thinks that the "shadow" on the edges of our wood trim make her think they are dirty. Just a thought. Maybe the edges could be lighter instead of darker. Maybe they wood knot look dirty to her then. Hmm.

As for mixing water with the glue, just remember that the MDF will suck up that water, and although there is no grain, the surface will become rough.

[reible]

I know that my wife thinks that the "shadow" on the edges of our wood trim make her think they are dirty. Just a thought. Maybe the edges could be lighter instead of darker. Maybe they wood knot look dirty to her then. Hmm.

As for mixing water with the glue, just remember that the MDF will suck up that water, and although there is no grain, the surface will become rough.

Thanks Tim

I guess I should mention it is 3 parts wood glue to 1 part water. I don't recall where I found/heard that some years back and tried it, and yes you do need to give it a light sanding after as I mentioned.

The shadow idea was shown on one of Norm's new shows on the kitchen rebuild. The homeowners mentioned it but they have it no where else in the house so I will relay the thoughts of your wife... and yours??. To me it is easier to make it all one color.

Ed

[tdubnik]

I am using sheetrock joint compound to fill the edges of MDF before snding and painting and it works pretty well but somewhat messy to apply.

[Gene Howe]

Hi Ed,
Both methods, dry wall mud, or glue, work. Of the two, I like the glue. I don't mix it, though. In one of Sommerfeld's videos, he suggests applying a thin coat to end grain of rails for doors so that they wouldn't soak up the assembly glue and starve the joint. That's when I started using it on MDF edges to be glued, also. For sanded and painted edges, I give it a light coat then, a second coat. That being said, on MDF raised panels, I just use oil based primer.

[Ed in Tampa]

My MDF must be different than your MDF. On mine I can sand it to as smooth finish as the top surface is. If I rout it the the edges look almost burnished.

I have never had to do anything special with my MDF edges if I was going to paint, tung oil them or coat them with Poly. The finish was thick enough so the result was basically the same top, edge, bottom.

[flyslinger]

Just another comment, you could do it a couple ways...if its not to big an area you could use spackle and if its alot of area I've use an mdf tape or maple tape and painted that.

[Gene Howe]

My MDF must be different than your MDF. On mine I can sand it to as smooth finish as the top surface is.

Many times, my experience has been the same. However, I have bought some from the BORG which did not perform as well. Especially 1/2", for some reason.
Recently, I learned that there are several different grades of MDF. Each one designed for certain applications. And different companies have different grading standards. i.e Asian vs US mfg. I've seen some whose faces were absolutely blemish free and others on/in which small specks of some matter (hopefully, wood) could be easily seen.
The MDF manufacturer's web sites I've visited, suggest priming with an oil based primer prior to applying a top coat. None has suggested treating edges any differently. That's just one of my many quirks.;)