by Stan Watkins
As presented at the Southeast Antique Wireless Association Annual Meet 3/24/2000
Note: This page is not completely finished. Some topics lack detail and the organization is still a little awkward. A number of people asked for this information, so I'm putting it up as-is.
Veneer problems encountered on Radio Cabinets:
- Loose veneer at edges
- Chipped veneer at edges
- missing pieces
- delaminated grills or panels
- Buckled and bubbled veneer
- Gouges
Repair options:
- Re-glue loose veneer
- Fill defect with wood putty
- Patch veneer
- Replace entire section of veneer
Re-gluing - The first step in most veneer repairs. If no wood is missing, this is the only step. Often, the veneer surrounding a missing piece is loose and it must be re-glued before the missing wood is replaced.
Filling - The simplest method is filling the damaged area with wood putty. This type of repair is good on very small gouges and chips. When a gouge or chip is 1/4 inch or smaller and is not in a very noticeable position, filling with wood putty provides a quick and unobtrusive repair. The wood putty must be the same color as the finished wood.
Patching veneer - Patching is usually the best option if done properly. With this type of repair, the existing original veneer is retained and only the missing wood is replaced. A good veneer patch will not stick out as an obvious repair. I patch any damage that covers less than 1/2 of the damaged panel.
Replacing sheets of veneer - Re-veneering is difficult and removes much of the original surface of the cabinet. In some cases, this is the only option. These cases include large sections of missing veneer, large sections of burnt wood, and cabinets that are missing large portions. When done properly though, a re-veneered surface will look as good as an original surface. The most commonly re-veneered section of radio cabinets is the arch on a cathedral radio.
Now we know the repairs methods available and how to select the one for our repair. So how does one accomplish the repair successfully? Read on...
Re-gluing Loose Veneer
The three main considerations on re-gluing are:
- Choosing the type of glue.
Hide glue or yellow woodworkers glue both give good results. I use the yellow woodworkers glue.
- Applying the glue. The best tool to apply glue between loose veneer and substrate is a hypodermic needle, especially the big ones used by vets on horses. Some industrial supply houses sell hypodermics that will work well. Slit the veneer along the grain with a craft knife in the middle of the bubbled area. Inject glue all around the loose area. Squeeze out extra glue before clamping or heating.Glue may need thinning. .
- Clamping the repair
When possible, use C clamps with boards and paper to hold repairs together. Do not let repair slide while clamping. I have even used tiny brads to secure pieces.
Use iron to hold veneer down and dry glue, especially for bubbled areas
Heavy weights for area than cannot be clamped. Consider disassembling cabinet if possible.
Another option - cut a small diamond in the middle of unclamped area. Drill hole, use bolt and wood to clamp area. Re-glue veneer diamond when other repairs are finished.
Patching veneer and re-veneering both involve selecting the proper veneer, so I'll cover that topic next.
Veneer comes in two basic types - Standard Veneer and Flexible Veneer. Standard veneer is approximately 1/40 to 1/32" thick. Standard veneer is made by slicing a log into thin sheets. Standard veneers are usually 3 to 12 inches wide and 3 to 10 feet long. Flexible veneer is approximately .1/64" thick and is made with a paper backing to give it strength. You can purchase it in widths of up to 48 inches and lengths up to 12 feet since the manufacturer joins narrow pieces to make a large sheet. Flexible veneer will conform to curved surfaces without heating or steaming and is very easy to cut. It is sold ready to finish and needs no sanding. Flexible veneer will not work for patching since it is much thinner than the veneer used on antique radios. The veneer on many old radios is 1/16 to 1/20th" thick. Flexible veneer is good when re-veneering a surface on a cabinet, especially if the surface is curved - such as the arch on a cathedral style radio. Standard veneer is the type to use for patching damaged veneer. Most of the common veneer types are still available in the thicker sheets and will work well for repairs to Antique radio cabinets. Constantines sells a variety of standard and flexible veneers. They also offer the old style thick veneer as used on older furniture.
Selecting the type of veneer to use
Patching: Use standard veneer, measure the thickness to determine if you need the old style thick veneer (1/16 to 1/20") or the newer standard veneer (1/32 to 1/40") One of the best sources for veneer is old furniture or radio cabinets. Cabinets that are beyond practical restoration are good sources for veneer. Old cabinets are more likely to have the proper type, thickness and cut of veneer you need for patching. I save some of the layers of substrate (the wood below the veneer) to repair missing pieces of substrate when patching..
Re-Veneering: Flexible or standard will work well for re-veneering. Flexible veneer conforms well to curved surfaces and is much easier to use, especially for the novice woodworker. Some flexible veneers come with the glue already applied and require only heating to set the glue.
Identifying the wood type It's not easy to know what type of veneer you need for your repair. If you already have veneer scraps lying around, you can examine the color and grain to find one that matches. If you have to buy veneer for patching, purchase a veneer identification pack first. Constantines sells these for $5. Other wood supply stores sell sample packages which contain a variety of pieces large enough for many patches. Matching the color can be tricky. You need to know what the veneer will look like when finished. I use a little solvent to wet the original veneer and the patch to compare color. When I find a match, I look for a piece with grain patterns that closely match the original.
Veneer Patches
Before patching a damaged area, the surrounding wood and substrate must be stabilized. Loose veneer surrounding the damage and delaminated substrate must be re-glued. I make these repairs before I even out the shape of the damaged area. If a layer of substrate is missing, find a sheet of wood with the same thickness and patch it.
Once the damaged area is repaired enough to patch, you need to even out the edges of the damage in order to fit a patch. The edges of the patch should be as close to parallel to the grain as possible. Never cut straight across the grain for a patch. The end of a patch should be cut at a diagonal to the grain, preferably less than 45 degrees. This helps the patch blend in with the original wood. A patch with an edge perpendicular to the grain will show up readily.
Cutting the patch: One method of making sure the patch is exactly the same size as the area needing the patch is to cut them both at the same time. In this method, a patch is laid over the damaged area. The damaged area is evened out by cutting straight edges along the damage while the patching veneer is held in place on top. This ensures that the patch matches the damaged area. I find this method difficult since the patching veneer tends to slip during cutting.
I use the tracing method to make my patches the same size as the damaged area. First, I even the edges of the damaged area using a metal straight edge and a craft knife. I cut the damaged area parallel to the grain and use diagonal cuts on the end. I remove as little wood as possible when evening out the damaged area. When the damaged area is ready for the patch, I trace the shape by holding paper over the patch and rubbing a pencil across the edges of the damaged area. It's just like the tracings we did of leaves and other textures in Kindergarten! Next, I cut out the tracing, but not right on the edges, a little extra margin makes the traced edge easy to see. I glue the tracing to the top side of the veneer patch with a glue stick, making sure the grain is oriented correctly (I draw the grain direction on the tracing for reference). Using the metal straight edge and craft knife, I cut the patch to match the tracing. If the patch is fragile or small, I leave the paper in place until after the patch is glued to the cabinet. I use the yellow glue to fasten the patch to the cabinet. Either clamping or heating with an iron work well to secure the patch. When ironing, I make sure the patch does not slip. If the patch is on the edge of a panel, I apply gentle pressure in the opposite direction from the edge to keep the patch seated firmly. I clamp a patch, I sandwich the repair area between two flat boards. I insert paper between the patch and the wood to keep excess glue from fastening the patch to the clamping board. When clamping, be careful not to let the patch move.
Re-veneering
Either standard or flexible veneer will work well for re-veneering, but flexible veneer is the easier to use when re-veneering an entire panel. Flexible veneer comes in large sheets, all defects in the wood are filled. This type of veneer is ready to finish as sold and needs no sanding. The only disadvantage is that it costs more than standard veneer. Next, let's look at how to glue the veneer to the substrate.
Contact cement is easy to use, but it does not dry as hard as most wood glues and can be dissolved by solvents such as lacquer thinner. When using contact cement, coat the veneer and the substrate with a thin even coat of glue. The glue may need thinning with lacquer thinner to obtain the correct consistency. Apply the glue with a roller or brush. Let the glue dry until slightly tacky (5 to 10 minutes). The veneer must be applied in the exact position desired. Contact cement does not allow re-positioning. Start applying the veneer at one edge (or in the center if you keep the edges from touching) and carefully work it onto the panel, making sure no air is trapped between the veneer and substrate.
Yellow Glue is a little harder to use than contact cement, but it allows more time to position the veneer properly and dries hard. Yellow glue is not readily dissolved by lacquer thinner. When using yellow glue, coat only the substrate with glue. Apply the glue with a roller or brush, the roller is preferred for more even and quick coverage. The glue may need thinning with water. When the glue is applied, position the veneer on the panel. When the veneer is positioned, use a regular clothes iron on high heat to set the glue. Cover the veneer with a thin piece of cotton (an old bed sheet will work). Start heating the veneer at one edge and work across the piece. Remove excess glue at the edges with a damp cloth before it hardens.
©2000 Stan Watkins
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