Many of the procedures and repairs described in Technical Tips involve high voltages, and semi-toxic paints, varnishes, strippers, solvents and the use of high temperatures. Work on a proper bench and in a well ventilated area.(The Editors)

By Glen Zook

When using real batteries with vintage radios, the set may work while the battery is at its peak power, but start to oscillate when the battery has less than full power. This condition is often due to the battery’s internal resistance which increases very rapidly as the battery nears the end of its useful life. The increased battery resistance allows positive feedback to occur across one or more of the receiver circuits. You can usually get a few more howl-less hours from your set by connecting a 0.02 microfarad mica or ceramic capacitor across the battery terminals.

By Herb Braums

Remove the old finish with liquid stripper using steel wool or a stiff brush (not a wire brush). Do not use scrapers that tend to leave scratches. Allow the stripped cabinet to dry for at least a day. Fill the small holes and other defects with a wood filler. Allow the filler to dry, then sand the cabinet by hand, first using a medium sandpaper and, then, a very fine sandpaper. Do not use a power sander or sanding block, as typically the wood curves slightly upward near the edges and it is easy to sand through the veneer. Always sand in the direction of the grain. After sanding remove all dust.

The stripped cabinet will now be much lighter in color than before restoration, and should be stained to improve appearances. Some parts of the cabinet may be beautiful mahogany or walnut veneers. These woods will reveal themselves clearly when the cabinet is wet with thinner. The fine woods are best left unstained. A clear yellow stain, such as MinWax Golden Oak may be used, however to give the wood a mellow tone. Dark stains should be avoided because they give a course, grainy appearance. Parts of the cabinet with fine woods should be stained and have a coat of finish applied to protect them before other parts of the cabinet are worked on.

Some parts of the cabinet may be made of plain, light colored woods. These often have prominent irregular grain patterns that do not stain well. To make these areas presentable stain these areas with a muddy, pigmented stain, such as MinWax Special Walnut. The opaque pigments will darken the wood effectively and tone down the unsightly grain patterns. Two coats of stain are usually necessary.

Some parts of the cabinet may not look good even after staining. These usually include the edges and base of the cabinet and the inside of the speaker grill. I paint these areas with a dark brown enamel paint obtained by mixing black with brown. This paint can also be used to accent lines and various pieces of trim.

For the final finish I use a satin polyurethane finish, applying it with a brush. Many woodworkers prefer a natural finish like shellac, varnish, or tung oil. Tung oil is particularly beautiful when several coats have been hand-rubbed onto a vintage radio cabinet. Avoid glossy finishes, they tend to be too shiny and show brush strokes.

Before starting be sure that all stained and painted finishes have dried for at least a day. Sand the wood very lightly to smooth it, but take care not to remove the paint or the stain. Remove all dust. Lay the cabinet down so that the working surface is horizontal. Brush the finish on so that is covers the wood completely, then go over it again holding the brush so that it touches the wet surface very lightly. This makes the coat even and removes air bubbles. Avoid slopping on a thick coat of finish, the excess will run and form sag marks.

Let the finish dry undisturbed for a day or more. Sand the first coat carefully with a fine sand paper and apply a second coat. Be particularly careful here to apply the liquid sparingly so that it is not absorbed into the wood too quickly and have a tendency to run forming sag marks. You will find it easier to do all of the staining and finishing on one side of the cabinet at a time. Be sure to immediately wipe up any stain, paint, or finish that runs onto a previously treated surface.

Often the old lacquer finish on a radio cabinet is stripped off and a tedious refinishing task is attacked when a simple restoration process could provide more authentic results with a fraction of the labor. A finish may be clouded and cracked but is restorable if it is intact, and has only light surface scratches (no gouges).

Materials required include liberal quantities of lacquer thinner and several sheets of 400 grit wet/dry sandpaper.

Using a soft clean cloth soaked in lacquer thinner, rub a section of the finish repeatedly until it begins to become slightly tack to touch. Then sand that section with the 400 grit paper. Repeat the process 3 or 4 times, and then move onto another section, until the whole cabinet has been sanded. Finally rub down the finish with a 0000 grade steel wool and a little lemon oil or furniture polish.

The results will be dramatic in most cases, and cabinets that are already in good condition can even be improved by using this method. It will remove most small surface scratches and imperfections and give the cabinet a hand rubbed finish and a color that is always authentic.

Using One Grand ( for most plastics and bakelite) or Blue Magic (Do not use this abrasive polish on Bakelite).

For cleaning bakelite only water repeatedly applied with cotton balls is recommended. Do not use ordinary house chemical cleaner. Use WD-40 or paint thinner in stubborn cases.

Always try the cleaner on a small hidden area before proceeding.

Use only hard epoxies such as Metal Mend or Epoxy Steel of bakelite. These are always gray in color when mixed. Avoid clear epoxies when working with bakelite. A product like Plastic-Zap can be applied to bakelite filings and placed in molds to harden.

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