Experiment before you commit

Having only recently added the vacuum press to my tool set, there are still many things for me to learn about that type of work. One of the most important aspects of veneering is the glue. Standard wood glue, PVA (Polyvinyl Acetate), is not ideal for veneering for several reasons.

PVA glue has too short and open time, cures too soft which allows the veneers or laminations to move (called "creep"), softens under heat (like direct sunlight) and is water soluble. Some wood workers do use PVA and are happy with the results, but I don't see the point is risking it when a little experimenting will prevent later problems.

There are a number of other glues that a available. But since long term stability is the
most important aspect, that is the first thing I look for in a glue. This means using 2-part glues, either epoxy or urea-formaldehyde resin glues. For this project I opted to use a pre-catalyzed water activated glue called Ultra-CAT by Better Bond. I chose this glue because it cures hard, has a long open time, and is more environmentally friendly than other similar glues which require a chemical catalyst.

The down side of 2 part glues is that they have to mixed in carefully measured proportions. Since I'd never used this glue before I made the wise decision to do a test panel from scraps. The instructions for the glue listed several mixing solutions using a combination of volume and weight measurements, which was confusing. To further complicate things, the instructions listed weights in hundredths of a pound, but my digital scale uses ounces, so I had to do a lot of conversion. In the future I'll probably work out my own ratios so I'm not locked in to the handful of specific amounts listed by the manufacturer.

My first attempt to mix the glue was a failure. While trying to make a smaller amount than listed by the manufacture and convert the weights and volumes to my scale I messed up the ratios and ended up with a glue so watery that it was virtually unusable. Not being familiar with the glue I still used this soup to make a small panel. The end result was unacceptable, the veneer peeled right off the panel.

So I made a second attempt and got better results. Since the glue needs 4-6 hours in the press and another 4-6 hours after to cure, these two tests took 2 days to complete. Time well spent when you consider the final product will involve over $1000 of veneers and be the focal point of the entire kitchen.

With the ratios worked out, I glued up both end panels for the island yesterday. The final product is out of the bag and cured. Ready to used.