Q:

I recently purchased several sheets of 12-in. by 24-in. crotch mahogany veneer. It arrived in a crumpled, wavy condition. The surface is not split or broken. How can I ever get this stuff flattened out?

Hadley, via Ask The Experts, None

A:

There are several methods for flattening veneer, and many involve soaking the sheets in a homemade solution or with a premixed product called GF-20, made by Borden. These solutions bind weak fibers in the veneer, making the veneer flexible enough to flatten under weight without cracking.

For minor, isolated instances of flattening, a household iron will do. Set the iron to the steam setting at about 150°F to 212°F. Then apply gentle pressure as you iron both sides of the veneer. The steam will increase the veneer moisture content making it flexible enough to flatten.

Mist veneer with homebrew solution
If the veneer is too wavy for an iron, I will spray the sheet with a mixture of water, alcohol, and glycerin, sometimes called a veneer bath. My bath is about 6 parts water, 3 parts alcohol, and 1 part glycerin. The solution will soften the veneer and keep it flexible during glue up. A common spray bottle is the right delivery tool. All it takes is a light misting on both sides to soften the veneer just before glue up.

Dealing with stubborn veneers
If the veneer is excessively wavy you will need to thoroughly soak each sheet in a veneer bath and then press the veneer between two boards until dry. For this case, Tage Frid formulated a classic recipe similar to mine above: 3 parts water, 2 parts plastic-resin glue, 1-1/2 parts glycerin, 1 part alcohol, and 1 part flour.

After the veneer has soaked in the solution for about 30 minutes, press each sheet individually between two sheets of plywood with about 10 lb. of weight applied. Also place ample layers of newspaper on each side of the veneer to absorb the water. The soy-ink print on modern newspapers may transfer to the veneer, so I like to use plain newsprint where it touches the veneer.

As the solution dries, you will have to change the paper two or three times to allow the water to slowly evaporate out of pressed veneer sheets.

Once flat and dry, the sheets should be kept between boards or heavy cardboard weighted with bricks until used. In fact, I use this storage setup for all my veneers.

Quick Tip: The cheapest place to buy glycerin is a feed store as it is given to rumen animals with colic. You can also buy it at a health-food store, but you will pay more for the same thing.

Find more answers or ask Ernie Conover a question in Ask The Experts.

Photos: Karen Wales

Fine Woodworking Recommended Products

AnchorSeal Log and Lumber End-Grain Sealer

Good for both sealing the end grain of freshly cut logs and boards, this wax prevents end-grain checking and saves material

Buy at Amazon

Bahco 6-Inch Card Scraper

The size and thickness are what matter here. A consistent performer, this Bahco scraper is found in many shops we visit.

Buy at Amazon

DeWalt 735X Planer

At high speed, the planer works fast and leaves a smooth surface. But the slower, finish speed produces an almost glass-smooth surface. Knife changes are easy.

Buy at Amazon