HINTS FOR APPLYING VENEER WITH CONTACT CEMENT
The use of a veneer press, either a vacuum, cold or hot press, using white or yellow glue, is the preferred method of applying wood veneer. If a press is not available, good contact cement may be used. Look for contact cement with the highest level of solids and follow the adhesive manufacturer instructions. (Flammable contact cement most often works better than nonflammable.)
- It is critical to the application to thoroughly stir the adhesives before each use, just as in painting. The solids and solvents must be mixed to form the best contact. Most people overlook this very important step. It is also critical to dry thoroughly — lightly touch to check if it is dry. If even the least bit sticky, allow to dry thoroughly. Store cans of finishes and contact cement off the floor during winter months.
ALSO, IT IS EXTREMELY CRITICAL to use maximum pressure when smoothing out the veneer. DO NOT USE A “J” ROLLER to smooth out flexible veneer. Instead, use a piece of scrap wood approximately 12″ long and 6″ wide as a veneer scraper. Lightly sand the 6″ edge to take the sharpness away and create a slight radius. The smaller the radius, the better as it will produce the greatest pressure. A 1/16″ radius will produce 4 times more pressure than a 1/4″ radius. Holding the scraper with both hands and using it like a wooden squeegee, smooth out the veneer from the center outward to the edges.
- While paper-backed veneer is intended for interior use, it can be used on an exterior surface only if an epoxy application is used. Call for details.
- Veneer must be bonded to a suitable substrate of a reliable quality. MDF (medium density fiberboard) is the most stable substrate, followed by industrial particle board, veneer-core plywood. The least stable substrate is hardwood.
- We do not recommend direct application to drywall, plaster walls, concrete walls or cardboard products, as delamination may occur. Veneer should be applied to MDF substrate to cover these surfaces. Installation over substrates that have been treated with a fire-retardant agent is not recommended.
- When veneering over bending plywood materials, we have found that laminating an 1/8” MDF over the surface makes it more stable (1/8” MDF can bend around a 2’ – 3’ radius).
- Prior to installation, the veneer should be allowed to “acclimatize” with the substrate in the same environment for about 48 hours. Make sure that both the surface to be covered and the back of the veneer are free of dust, dirt, oil, grease or any foreign matter.
- To avoid sealing in too much moisture, it is best to finish the veneer when the humidity is less than 51%, as it may shrink when placed in a climate-controlled environment.
- Wood veneers rely 100% on the adhesive. Ask your supplier which content cement contains the most solids. Even though it is more expensive, it is goes much farther and will be less costly in the long run. Both the veneer back and the substrate require 100% contact cement coverage. Often, a second coat is needed on the substrate, as the first coat may be partially absorbed. The first coat acts as a sealer, the second coat is the glue.
- Allow proper drying time (“flash time”) between coats. Normally there is a generous window of time. Glues should be completely dry before applying the veneer. Anything less creates the risk of a weak bond between the two glue lines. Rushing can lead to solvent pockets appearing as bubbles.
- When using contact cement, a pinch roller is preferred for pressing veneer on the substrate as the amount of pressure is very important to activate the glue. A flexible wood scraper may be used if a roller is not available. Do not use a J-roller, as it does not allow you to apply enough pressure directly onto the veneer. Also, to avoid bubbling when hand pressing your veneer on the boards, be sure to start in the middle of the board and work your way to the outer edges.
- After applying veneer, allow adhesive to dry 24 hours before applying any finish. Apply the finish in light, even coats. Two thin coats are always better than one heavy coat. Allow 24 hours drying time between stain and sealer to let stain totally dry.
- When finishing veneer with two-part catalyzed finishes, be careful not to make your finish too thick. Some finishes will crack or check when they are more than 4 mils thick. Check with a finish manufacturer. Vinyl sanding sealer is a good choice when sealing your furniture, as it has excellent moisture and is vapor resistance.
- Check finish instructions to make sure that you have the proper time and temperature for your veneer to dry. (Example: catalyst finish should dry at 68-75-degrees for six to eight hours.) It may be a good idea to take a short course on stains and finishes. Some companies offer these courses for little or no money. They can be most helpful. M.L. Campbell is one such company.
- Water-born stains and finishes are not recommended for finishing veneer, unless you seal the veneer with a vinyl or acrylic sanding sealer first.
- Do not apply veneer to a two-sided melamine coated board. Do not sand melamine from a two-sided melamine board to apply veneer, as bubbling could result. If the board comes from a manufacturer with one side melamine and the other side raw, you may apply the veneer to the raw side.