On Jan 16, 1:28*pm, "SonomaProducts.com" wrote:
If you have seen any of my posts before, you'll know that I usually
think I know it all but apparently I don't and now I have a few
questions. My domain consists of solid wood and the ocassional ply for
all my finished goods type production. I use MDF all the time for
fixtures, etc. but have never incorporated it in a finished piece.

I am building a fireplace surround and mantel for my new home. It
seems best to build some of the parts from MDF. It will be painted.

Q's.

1. Is MDF paintable? It ssems the moisture will screw it up. Is there
some priming method required?

2. I seem to recall a variant that has a paper coating. Is that
required?

3. What about edge prep if you are using the papered version.

4. I will have a scenario where I want to use butt joints. I want to
sort of puttey the end grain (or edge) and fill the gap of the butt
joint and sand it out smooth so it won't show once painted. Could I
just use like sheet rock taping compound or is there something better?

BW

What we have done, with good success, is to fill the edges of MDF and
plywood, which are very absorbent, with lacquer-based automotive
putty. One brand we use is called Green Stuff. It is the last filler/
putty automotive guys use before they spray on the primer. It dries
quickly and sands beautifully.