Veneering MDF

Advice on a balanced veneer layup for an MDF-core countertop. November 26, 2008

I am adding veneering to my shop capabilities, and am relatively new to this craft. I am constructing a 2' x 8' countertop for a dry bar. The finished thickness needs to be about 1 1/2". It will have a hard maple front nosing 2" wide by the same 1.5" thick. The other three sides will butt up against other surfaces and not be exposed. Six feet of the counter will be supported by base cabinets with solid tops. The last two feet span over a wine cooler with support at the very end.

The veneer top will be 2-ply Wood-on-Wood quarter-sliced white maple. I have a backer veneer that is of 2-ply WoW plain-sliced maple. I would like to use 3/4" lightweight MDF for the substrate. The lightweight MDF is preferred to avoid the weight of regular MDF. (I work alone.)

My thought is to use, in order from the bottom, 1) backer veneer, 2) 2 sheets of 3/4" MDF, 3) good veneer. The adhesive will be Unibond 800. I know that a balanced panel should always be an odd number of plies. And 6 is not an odd number!

After vacuum veneering, the edges would be trimmed, the solid maple glued on, and a profile routed on the solid edge. Does anyone have any comments on this, either pro or con?

Forum Responses
(Veneer Forum)
From contributor E:
Assuming this top is going to be screwed to the cabinets, once it's screwed well, it should stay put. I would use one piece of MDF. Build it up like a laminate top. Not veneer the bottom. I put a coat of sealer on the bottom of veneered tops. Have never had a problem doing it this way.

From contributor J:
Your construction method is fine. The rule about odd numbers of plies has more to do with balancing opposing grain directions in veneer cores, which does not apply in this case.

Do use the balancing veneer on the bottom. You would be surprised what one l'il ol' veneer face can do to a sheet of MDF when it's the only one on there.

You might want to consider putting the nosing on the MDF before you apply the top veneer. There are two schools of thought on this, but this is what I prefer.

From contributor S:
I agree with contributor J on the edge. Biscuit the edge onto the MDF with epoxy, then veneer. You could even put a bull nose in the edge and let the veneer wrap around it in the bag.