Gluing Veneer to Glass

Advanced tips for using silicone to glue veneer to glass, from a chemist who knows. October 20, 2005

Question
What kind of glue is best to attach thin paperbacked veneer to glass? I was thinking silicone. What do you guys think?

Forum Responses
(Adhesives Forum)
From contributor A:
I'd use polyurethane construction adhesive. Spread it out with an old fine-tooth backsaw blade used like a trowel. It sticks to everything except poly sheet-like vapor barrier or garbage bags. It does cure in a vacuum bag. My secret is out now for sure.



From contributor B:
As a former adhesive chemist, I formulated some interesting UV cured clear laminating resins for bonding funky stuff to glass. I now do this for a living, but my adhesives are proprietary. I will tell you this - if you are looking to bond veneer to glass so as to view the veneer through the glass, silicone is not a bad method. PUR's will bond to glass, but are not clear. They will disrupt the beautiful veneer.

The key is to get the silicone to cure without locking it in and preventing drying. This is hard to do when itís entrapped. I've successfully bonded ink-jet printed photos onto glass using silicone, as I knew that the silicone's solvent, acetic acid, would evaporate through the paper.

Veneer will do the same, but may not lay flat after you've rolled it on and clamped. You'll need a honeycombed clamping caul to allow drying while under clamp pressure. I almost guarantee this will work. You may need to thin the silicone with acetic acid (stop bath at photographic supply store) to get it to squeeze out better. You can roll the silicone or better yet, put it though a pinch roller. I'm biased towards silicone because it bonds to glass very well. PURS are not quite as good, but close. Do a test first. Epoxy does not work on glass - don't even waste your time, unless you use the special epoxies used to bond rear view mirrors to windshields.

Commercially available two part and UV glass laminating resins probably won't work due to oxygen in the wood inhibiting cure. UV glass glue, however, might work. These are different from UV laminating resins.

Loctite 352, found in McMaster Carr catalog, might work. I've glued small sections of plywood to glass using 352. It needs an artificial UV lamp to cure fast, or bright sunlight will also do the trick.

Also, I forgot to mention that paperbacked veneer will entrap the solvents in the silicone and it won't cure. Use raw veneer so that the acetic acid can escape through the pores. Finishing will be difficult, of course. You may need to seal with shellac as a first coat.
My first approach is still to bond to the glass, and use the glass as the viewing surface. Rather than a honeycombed clamping caul, a simple kerf-grooved panel would be fine.



From contributor C:
These are doors for an entertainment center. The glass is rectangular and the veneer was to be completely finished (NGR stain and topcoat) and then attached to the glass with the veneer on the outside, similar to an onlay. I didn't think about putting the veneer behind the glass.

I can also get a slightly thicker veneer without a paper back, more like a thin piece of plywood. I liked the thin paperbacked at first, but the thicker veneer, stained and clear lacquered and attached to the glass, might work better. If I lacquered it after the silicone set, would any residual affect the NGR stain or topcoat? What about using a dab of silicone at the corners and a few in the middle and washing the backside with silicone? Could I use a clip or some thin adhesive tape?



From contributor D:
There is a clear plastic (acrylic etc.) saturated veneer product available that is used for lamp shades and light panels that can be attached with contact cement, usually to Plexi-Glass. The veneer is an architectural grade AA product that requires no additional backer and is a product of Jacaranda, Inc.