Filler for mdf mouldings

[mikhamora9]

What is a good filler for covering nail holes in mdf crown amd baseboard? I've tried caulking on past projects, but that tends to leave a smudge, and doesn't generally take paint well. Which products do you use?

Thanks

 

[S. Pupp]

I use DAP Fast’N Final spackle. When it’s dry, I paint over it with a small water color paint brush. The results are adequate.

 

[Certificate of Excellence]

I use a solvent based filler like plastic wood. Water based paints/fillers/caulk will react to unfinished MDF which is what nail holes and seams effectively are. This prevents water based fillers from setting/curing correctly as the MDF holds onto the filler moisture. I have used solvent based paintable caulking to fill tiny holes as well but it does shrink over time, so for seam repair or larger holes, it will look good for a few years but can shrink and separate/divot leaving a future repair for you, so something to consider.

 

[S. Pupp]

I use a solvent based filler like plastic wood. Water based paints/fillers/caulk will react to unfinished MDF which is what nail holes and seams effectively are. This prevents water based fillers from setting/curing correctly as the MDF holds onto the filler moisture. I have used solvent based paintable caulking to fill tiny holes as well but it does shrink over time, so for seam repair or larger holes, it will look good for a few years but can shrink and separate/divot leaving a future repair for you, so something to consider.

That’s a very good point.

 

[Trash80toG4]

Interesting, I've never had a problem with MDF using the likes of spackle or latex paints,

I'd think the MDF moldings would suck the water out of the filler, drying it faster than air? The problem with moisture and MDF is that it bloats and loses structural integrity when it soaks up too much water.