Choosing Glues for Flexible Veneers

Different types of glues can be used, but each requires that the proper technique be followed - 1998

Q. I want to coat mahogany lumber core plywood AA2S with paper-backed flexible mahogany veneer for a two-face match using hot hide glue. Can you get me references for technique or suggest an alternate scheme?

A. There are a number of options available when applying backed veneers. The largest consideration is the type of equipment you have available.

If you have a small shop without a press your best bet is to use contact cement. This is really the best way to apply backed veneers without the aid of a press. The only drawback is that the bond is immediate. You won't have any time to position your pieces.

All other adhesives really require the use of a press. Presses vary from simple vacuum bag presses to complex multi-opening hot presses.

Vacuum bag presses are relatively inexpensive and can be used for a wide range of applications. When using a vacuum bag press with a backed veneer, most PVAs (white or yellow glues) will do a very good job. They allow for positioning of the veneer on the substrate and only require pressure for 30-60 minutes.

Hide glue could also be used in this situation but it wouldn't really give you any benefits over a PVA. It's probably is not a good choice for this application because it: has to be heated, smells bad, is not resitant to moisture, and offers no appreciable heat resistance.

For larger applications involving hot presses or multi-opening cold presses, a urea resin/catalyst system is ideal because of the bond quality developed.

Finally, as long as you are using backed veneers there are many adhesive options open to you. If you decide to use raw veneer, urea resin is the best choice.

Jeff Pitcher is Marketing Director for Custom-Pak Adhesives in Newark, Ohio.