I’ve heard quite a few horror stories from wood- workers about the first time they tried using contact cement. They typically involve having to rip off a whole sheet of plastic laminate or expensive veneer that was set down crooked. Despite these mishaps, using contact cement does not have to be a terrifying experience. As long as you keep a few points in mind.
HOW IT WORKS.
If you’ve never used contact cement, there are a couple things you should know about this adhesive. Contact cement works by sticking to itself. So it has to be applied to both surfaces being joined. And like the name implies, contact cement bonds on contact. Once the two adhesive-coated sur- faces touch each other, you’ll have a bear of a time trying to get them apart without ruining one or both of them. So it’s important not to rush the process.
USING CONTACT CEMENT.
The first thing to consider when using contact cement is safety, (see below). After taking the necessary safety precautions, the next step is to apply the adhesive to the workpieces. To do this, I use a disposable brush or roller because contact cement is difficult to clean out of a brush. Whether you use a brush or a roller, it’s important to lay the contact cement down with only one or two strokes. That’s because if you continue to brush over the same area, the contact cement starts sticking to itself and balls up.
TWO COATS.
The first coat of contact cement will soak into the surface of the work- pieces, so I usually apply two coats. Just make sure you let the first coat dry before applying the second one. Otherwise you’ll have a hard time spreading the second coat on smoothly. The most common mis- take is joining the two pieces together before the second coat has dried. Check the contact cement by feel. It should be slight- ly tacky, but it shouldn’t stick to your fingers. (It will also look dull.)
JOINING THE PIECES.
Joining the two pieces is the critical part of the operation, especially with a large project like the computer desk. In order to position the laminate over the desk, I placed several narrow strips of wood between the two pieces, see photo above. Then after positioning the laminate, I pulled the sticks at one by one, starting at the center. To make sure the two surfaces are tightly bond- ed, I go over them with a J- roller. The roller allows me to concentrate a lot of pressure on a small area. But if you don’t have a roller, you can use a hammer and a block of wood. Just move the block around the surface of the top, tap- ping on it to press the two pieces together.
Safety First.
Most contact cements contain vapors that are highly flammable and potentially
harmful to your health. So I take safety precautions seriously.
To start with, I only use contact cement outdoors or in a well-ventilated area. And I never use it in the presence of an open flame (like a gas water heater or furnace, for instance). Since the vapors are heavier than air, make sure they don’t travel down air vents and collect at a lower level of the house (like a basement) where they might ignite.
Finally, to protect myself from the vapors, I wear a respirator. Most respirators designed for paint mist or organic vapors also provide protection against
contact cement vapors.
Contact Cement Tools.
Like any job, it helps to have the right tools when working with con- tact cement. To start with, you’ll need a disposable metal container to hold the cement. (The solvents in contact cement will dissolve most plastic containers.)
For small projects, I use foam brushes for applying the contact cement. (Disposable bristle brush-
es tend to fall apart.) But for large surfaces like the computer desk, I use a disposable 3" trim roller. Then to roll out the air bubbles, I use a “J-roller,” see photo.
Finally, I always keep a can of contact cement thinner on hand for clean up. It can also be used (if you’re careful) to separate the two
pieces in case of a mishap.
