Veneer Glue Options
Pros tell which glue types they like for vacuum-bag veneering work. July 28, 2006
Question
I'm new to vacuum pressing, having done hammer veneering before. What is the best glue to use in a vacuum press for flat panels?
Thanks for any help.
Forum Responses
(Veneer Forum)
From contributor A:
Titebond's cold press glue is excellent and specifically designed for vacuum and caul press applications. For laminated bent forming, or if you need more open time, epoxy is an alternative but requires considerable prep work to make sure it doesn't stick to everything.
From contributor B:
Don't overlook ureas - they have some really great properties and most people who get seriously into pressing veneer use them. For your situation, look at Unibond 800 which is sold by Vacuum Pressing Systems.
From John Van Brussel, technical advisor, Veneer Forum:
Veneer Systems supplies powdered plastic resin glue which is similar to Unibond 800. Our product is a pre catalyzed resin powder which you add water to. The advantages being lower cost, cheaper freight cost and longer shelf life over Unibond 800. If you are doing lighter colored woods you can tint the glue with TiPure to make it a lighter glue line.
From contributor C:
Powdered plastic resin is difficult to mix (too many persistent lumps) and you may have problems using a glue with water in it in some applications. I am a big fan of Unibond instead of PPR. For small, less critical jobs - interiors of cases, backs etc. - I like to use Titebond Extend type II. As with all PVA's, get it under pressure quickly to avoid dry spots. Sometimes I will roll the perimeter of the veneer before placing on the core also.
The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).
Comment from contributor H:
Unibond 800 works well, but it I quit using it because of the color it imparts on maple and cherry. It is sort of a greenish tint that is not pleasant. There is a warning on the product about this. Also, many epoxies will not cure in a vacuum. The catalyst separates from the resin and it will not cure. The biggest problem with using water-based glues like Titebond, which is what I use, is that the moisture in the glue will cause the veneer to expand a bit (or a lot) before the glue tacks, sometimes causing buckling.
