Webbing type adhesives and veneer

Ar canister spary systems appropriate for use with sheet veneer? September 25, 2002

I'm looking for feedback on using canister spray contact adhesive systems like F200 from Formica or Sta-Put, for use with bubble-free veneer or Phenolic backed veneer. Other backed veneers are not a consideration. Application is only to glue veneer to large curved walls where other methods are not feasible.

Forum Responses
I don't recommend webbing contact adhesive for any sheet veneer product. But if you must use that type of adhesive, use the phenolic backed sheet veneer. Apply as close as possible to 100% coverage on both surfaces. Leave open at least 45 minutes before applying the two surfaces together. Then apply as much pressure as possible with a wood scraper.

Locke Wilde, forum technical advisor

Locke, why don't you recommend webbing type adhesives on sheet veneer?

I know 10 and 20 mil paper back will telegraph the glue pattern, and will offer no barrier to finishing products. I'm curious about its use with sheet veneers with suitable backs for contact adhesive. Bubble-free paper backed veneer has alternate layers of paper and melamine resins, the resins offering the proper adhesive barrier, or so its suppliers claim. What is it about the adhesive you feel is not good with this type of sheet veneer - adhesion, telegraphing, or barrier to finishing products? Which contact adhesive would you recommend? Is there a sprayable adhesive that lays down flat that is a canister system? If not, what is a good spray adhesive using the typical pot setup?

Most canister adhesives come out in a heaver web pattern than conventional spray adhesives do with a gun that you can regulate. The problem with the web type adhesive is the buildup. When you start doing a box coat pattern to apply your adhesive, the overlaps can build up too much in some areas, while in other areas you still need to apply more adhesive to get 100% coverage on your two substrates. Well, if you look at this happening on the back of the sheet veneer and also happening on your substrate, the build you get in some areas is too much adhesive. The pressure from a wood scraper won't even take out the limbs and unevenness.

Yes, you are correct that the thicker backers help mask this problem somewhat. The reason is that they are more ridge and more forgiving. They hide more imperfections in substrates and your glue line, but they will fail. They are not totally blister free, check free, or free from any other problem that is caused by improper installation. I have seen failures in all sheet veneer backers over the years. But the largest reason for failure in sheet veneer is at the glue line - either not enough adhesive, not enough pressure or wrong adhesive and wrong pressure for the job.

If the canisters work for you, then go for it. They don't work for me because I don't want to limit myself to using only thick backers on my faces of veneer. Thick backers won't allow me to bend 90 degree corners and 1/8" radius or 1/4" end grain bends. I don't think that veneering should be applied just to flat surfaces.

Locke Wilde, forum technical advisor