Learning how to veneer wood opens a whole new world of possibilities in woodworking for even experienced artisans. The nearly endless variety of exotic wood species available in veneer can’t be matched. Properly veneered surfaces are just as durable and attractive as solid wood. Even the simplest of projects can become prized heirlooms. Whether you prefer old-school hammer veneering or modern vacuum pressing techniques – it’s always a plus to learn a few new tips.
Preparing the Surfaces
No matter which type of substrate you use, it’s vital to properly prepare the surface to ensure the best bond. Most substrates require little more than a quick (80- or 100-grit) sanding. MDF especially is very smooth, so sanding will scuff off the factory finish.
Paper-backed veneer may also require sanding or a quick wipe with lacquer thinner to roughen the surface. Always test it first by putting a drop of water on the backing. If the water beads for about five seconds, the surface needs roughing.
Most raw veneers don’t need prepping, but some exotics have a high oil content. This can be reduced by wiping the surface with naphtha before starting the bonding process.
Use the Proper Glue
There’s a wide range of adhesives on the market, but choices should be made according to your level of expertise, the method and equipment you’re using and the type of substrate and veneer you’re working with.
• Cold press veneer glue is the ideal product because it dries quickly, very hard, doesn’t require measuring or mixing and it’s very tolerant of mistakes.
• Contact cements are easy to use, but are only appropriate for two-ply or paper backed veneers. Wood veneers with no backing should never be used with contact cement because it can cause cracks, delamination and seam separation.
• Yellow PVA glue isn’t a good choice for veneers. It never fully hardens, which allows the veneer to move during changes in humidity. Its thin consistency also allows it to bleed through and discolor veneers.
Even the finest veneer species can contain minute surface imperfections, splits or holes that need attention. The good news is that most of these problems are easily corrected. Here are a couple of examples.
Pin Holes: Burls especially can develop tiny holes during the drying process. Using a wood glue that closely matches the tone of the wood and a breather mesh in a vacuum press often fixes this defect because the mesh allows the glue to escape through the pin holes. Otherwise, a custom wood filler can be made by mixing veneer glue with fine sawdust.
Bubbles: Blisters or bubbles under veneer are caused by air, too much glue or inadequate pressure during pressing. If ironing doesn’t work, slit the middle of the bubble along the grain using a sharp utility knife and work some wood glue under both sides of the slit. Protect the surface with a cloth and iron the bubble on a medium to high setting. The heat will help speed glue drying time.
Staining and Finishing
Veneer will easily accept finishes and stains, with the options nearly endless. Ultimately, it’s up to you to decide which way to go. Most burls usually aren’t stained because the natural patterns and colors are already beautiful. One common exception to this unspoken rule applies to walnut burls. A medium or dark oil-based stain enhances the wood’s richness without affecting the tones.
Koa is another veneer not typically stained. The natural colors are vivid enough that it only requires a top coat of an oil-based polyurethane to enhance the pattern.
The myth about veneering being a difficult process is just that – a myth. The methods are easy, the materials and tools are available and the basics are straightforward. Besides, it’s another impressive way create beautiful wood pieces.