Veneer on Moisture-Resistant MDF

Thoughts on applying wood veneer to exterior-rated MDF. March 13, 2009

I am making some mahogany veneered vanities in a high residential job. I want to use a moisture resistance substrate, and I was thinking of using "Extira" MDF. Does anyone have any suggestions?

Forum Responses
(Veneer Forum)
From contributor R:
Are you pressing the Extira yourself? If so I recommend using a Type 1 glue. If you don't use a water resistant glue line using Extira defeats the purpose. Also check with your glue supplier. I have used Extira before for this exact application with maple and found that the catalyst in the glue turns the veneer black. If it's only a few vanities why not just use solid mahogany?

From the original questioner:
Yes we would be pressing the veneer with a type 1 glue. This is a furniture style vanity, C-shaped made up of 3" wall thickness. I just would feel better having some type of moisture resistance substrate. I was originally going to use Medex (moisture resistance MDF) was thinking the "Extira" would be more MR than the Medex.

From contributor E:
I would just use ply (birch or luan) to glue-up the veneer on. I use Unibond 800 and can wash my panels down with water, without veneer or substrate problems. As long as the client isn't going to leave wet towels on their tops you shouldn't have any problems, given the proper finish. Why would you make the "wall" thickness 3in? 3/4" thick in a "C" shape would be very strong.

From the original questioner:
When I say 3" wall thickness, I mean I will frame up to appear to be 3" thick (has changed to 2-1/2").

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From contributor G:
I think you'd be ok with either. Extira claims more MR, but in my non-scientific, arbitrary sample testing, I can't say either outperformed. I'd be more concerned (as already pointed out) with glue-line and finish. I would fill pores to prevent soap/water/muck build-up-perhaps you've already solved that.