Getting a Good Bond with Paper-Backed Veneer

Quick tips on adhesive choice, prepping the paper surface, and using cauls for more even pressure to achieve better adhesion. May 30, 2011

Question
I'm veneering a bunch of wenge veneer with a 10 mil paper back onto plywood. When I did this in the past with contact cement, I had no problem until the last time. The veneer was perfectly flat in my shop for weeks with a CV finish on top, even after install. A couple of months later the veneer doesn't appear to have moved (edges are smooth, can't feel or see movement), but there are lots of small peaks as if the wood had been crushed together. This time I decided to use epoxy (West Systems), left it in the bag overnight, and to my surprise I could peel it off (with difficulty, but in big chunks). And yes, the epoxy was mixed correctly - the cup remnants were hard as a rock.

I then tried TBII Extended glue and it seems to work the best of all after letting it cure for a couple more hours out of the bag. I'm still a little leery though. I thought for sure epoxy would bond. Is there something in the paperback resin that would prevent proper adhesion? It has me a bit worried about the yellow glue, but it seems to be working. Should I be worried in the long run?

Forum Responses
(Veneer Forum)
From contributor T:
Never use contact cement, unless it is phenolic backed veneer (like Lamin-Art's Veneer Art). If I use paper backed, I always sand and clean the paper side for good measure. I am sure it depends on the exact environment, but I have had success with TB II. I prefer the Titebond cold press myself, along with MDF as the substrate.

The original panel you cemented may have had an issue with the CV dissolving the contact cement? Was it solvent or water based contact cement?



From contributor J:
I ran into the same problem a few years ago. West Systems epoxy, paper backed veneer and MDF substrate on a curved part. I started using cauls on everything, and the problem went away. In this case I bought some 1/4" kerfed MDF with the kerf side up, which was perfect because it made its own bleeder network. Perfect bags after that.


From contributor P:

I use Unibond 800 UF glue with paperback veneer in my bag. Never a problem.


From John Van Brussel, forum technical advisor:
For better glue bonding, you can scuff sand the paper backing. This opens up the paper backing to allow for better glue penetration. For paper backed veneers you can use FSV (flexible sheet veneer) glue. This is a fast tack PVA specifically formulated for paper backed veneers.


From contributor C:
Urea resin is the best way I've found.