best grain filler ?

[worsley947]

Hello all you wise men,
Can you tell me which is the best wood filler for making mrmdf edges smooth so that I can paint them so they don't show as I am making a built in tv/shelving unit with only 2 small doors
thanks dave

 

[Silas Gull]

I have always been dubious about the way MDF edges 'hold on' to conventional fillers. I think it sucks on them so much that a y curing or drying is compromised.
I just use PVA and then Sand smooth.

 

[rafezetter]

PVA works OK, but I prefer to use liquid epoxy for large areas, the kind used for fibreglass matting - just drizzle it on and smooth it out, it'll get soaked up almost instantly. Put some on to wet it, then again to make sure there aren't any "dry" bits. Once it's gone hard - the edge of the MDF will be rock hard and a sand will bring it up smooth - for painting go to about 320grit, but no more or you'll have adhesion problems. Wipe off the dust with white spirit.

Best done with the edge horizontal and cover the side edges with masking tape and try to catch any drip runs.