Replies

1. 
   nazard | Nov 08, 2006 04:18pm | #1

   Drywall mud.  Just rub it in with your fingers.  Let it dry then sand and finish.  I use a gray Skotch-Brite pad for rubbing non-flat surfaces.

2. 
   nikkiwood | Nov 08, 2006 05:16pm | #2

   ditto for the finger smear of drywall mud; I then prime it (the edge) twice before moving on to the regular paint.

   ********************************************************
   "It is what we learn after we think we know it all, that counts."

   John Wooden 1910-

3. 
   BilWil | Nov 08, 2006 06:12pm | #3

   It depends on how smooth you want the edges to be when all is said and done.

   The dry wall mud approach is a good one, using ordinary white glue as a sizing works for some, others just sand and prime the edges with oil base.  A shellac based primer is a good choice because it dries quickly, doesn't have any water to swell the MDF fibers and accepts both water base and oil base finish coats.

   If I'm concerned that the machined portions of the MDF are as smooth as I can make them, for example MDF raised panels for cabinet doors, I prime with 1 to 2 pound shellac, sand with 120 after the shellac is dry, rub on dry wall mud , sand with 220, another coat of shellac, sand with 220, prime and paint.

1. 
   Telco_joe | Nov 08, 2006 06:42pm | #4

   Golly! I have not worked with shelac since I was in my high school shop class.

   What is 1 to 2 pound shelac? I hope you can buy it in a can!

1. 
   Rich14 | Nov 08, 2006 07:59pm | #5

   Joe,

   You'll find that a lot of us here are very partial toward shellac. You can buy Zinser's shellac in 2 lb cut at almost any hardware type store.

   A 1 lb cut of shellac is one lb disolved in 1 gallon of denatured alcohol. Or any other ratio that results in the same concentration. A 2 lb cut is 2 lbs of shellac in 1 gallon of alcohol. If you dilute a 2 lb cut with an equal volume of denatured alcohol, you have a 1 lb cut.

   Rich

   Edited 11/8/2006 12:02 pm ET by Rich14

1. 
   Telco_joe | Nov 08, 2006 09:14pm | #6

   Thanks Rich.

   I knew it had to the mixture, but again it has been a long time.

   Thanks heavens for the 'Cut and Paste' and the download to PDA's. My memory is short.

   The Zinser's approach seems to be the best way to go for now. I certainly like the absence of water that causes the MDF to swell.