Bakelite Radio Cabinet Repair

As Antique Radio Enthusiasts turn more to online auctions sites to find vintage radios, we, as a group, are going to see more incidents of crack and broken Bakelite cabinets damaged during shipment. 

Gone are the days of great garage and yard sale vintage radio "finds", at least in my part of the country.

While most auction sites and shipping companies offer financial remediation, at the end of the day you are still left with a radio with a broken cabinet.

Here is an example of a recently acquired radio I received from an eBay seller. The radio was securely packed yet it was still damaged in shipment. The divider piece, labeled "Consoltone" completely snapped off and there were small Bakelite pieces that fell out of the back of the cabinet. It is important to collect all of these pieces and you will need then for the repair.  

Here is a picture of the jagged crack on the side of the radio. I hope I can find all of the Bakelite pieces so I can glue them back in place. 

What is Bakelite?

​Bakelite is an early form of plastic, developed by American chemist Leo Baekekand in 1907. It was one of the first plastics to be made from all synthetic or man-made compounds. 

Molded Bakelite forms in a condensation reaction of phenol and formaldehyde, with a wood or asbestos fiber as a filler, under high pressure and heat.  Bakelite only needs a few minutes to cure. The result is a hard plastic material.
 
Bakelite enabled electronic manufactures to produce low cost radios for the masses as it allowed them to mass produce identical molded cabinets quickly and with much less labor that traditional wooden ones. 

Step 1 Clean Cabinet

You need to throughly clean the radio cabinet once all of the electronics have been removed.  I use a bucket filled with water and dish washing detergent. A toothbrush and vegetable scrubber work great for getting the dirt out of small crevices. I then rinse the cabinet off with water and dry with chamois lint free towels. I let the cabinet dry overnight before performing the next step. 

Step 2 Initial Gluing 

I used Loctite Super Glue, a Cyanoacrylate based adhesive, to glue all of the broken Bakelite pieces back in place. Super Glue adheres well to the porous Bakelite material. Here is a picture of the Zenith Consoltone cabinet show the divider missing. 

Pictured below is the cabinet with the divider glued firmly in place. The Loctite Super Glue does give a few seconds to reposition the work before it dries, holding the piece securely in place.

For long cracks, I apply a thin coating of Loctite Super Glue to the all mating surfaces then hold the pieces together. I then apply clear packing tape over the glued joints to hold them in place during the drying process. I leave the packing tape in place for at least 24 hours.

After 24 hours, when I am sure the glue holding the mating surface is dry, I apply another bead of Loctite Super Glue to the crack from the inside of the Bakelite cabinet. 

Step 3 Reenforcement

I reenforce the bonding power of the Loctite Super Glue with a bead of JB Weld over the crack on the inside of the cabinet. Some Antique Radio Enthusiasts prefer Fiberglass Mat impregnated with Cyanoacrylate based adhesive. I chose JB Weld because it has a fairly long set time, making it easy to work with and clean up. In addition, it can be sanded and painted making the repair less visible to the naked eye.

I also apply a JB Weld to act as a filler when small Bakelite pieces are missing. Below is a picture of the recently glued divider with JB Weld applied at the mating joints.

Step 4 Sanding the Seams

I use a orbital sander to sand the all the seams that were filled in with JB Weld. Here is a picture of the seams sanded on the divider. 

Here is a picture of the seams sanded on the exterior of the cabinet.

Finally, here is the seam sanded on the interior of the cabinet.

Step 5 Initial Wet Sanding

I cover all vintage decals on the inside of the cabinet with plastic prior to doing any wet sanding.

I use 600 Grit wet sandpaper to completely sand the exterior of the cabinet, removing any surface impurities or stuff like paint flecks.

​I find a lot of vintage radios with paint flecks on them, as they were used as entertainment while performing chores like painting the house, before they met their demise.

I make sure I use plenty of water on the surface while sanding. 

Step 6 Primer Coat

First I mask off the large openings in the cabinet and apply a "paint prep" degreaser to the exterior surface. Then, I apply a liberal amount of Rust-Oleum Automotive Filler Primer to the surface. I chose filler primer as the exterior of the radio cabinet had many imperfections and scratches. 

Step 7 Wet Sanding the Primer

After allowing the primer to dry for at least 24 hours, I wet sand the primer on the exterior of the cabinet with 600 Grit sandpaper.

I attach a sanding block to the sandpaper when sanding over the glued joints in order make the transition less noticeable.

On this radio cabinet, I had to perform several cycles of applying a new primer coat to trouble areas then wet sanding again to get the surface ready for paint. 

Here is a picture of the radio cabinet ready for paint!

Step 8 Final Paint

As with applying primer, I mask off the large openings in the cabinet and apply a "paint prep" degreaser to the exterior surface prior to paint. 

Here are some important tips when painting a radio cabinet:

1. Test the color of the spray paint before applying to the enclosure. I typically spray some on a paint stirrer then let dry to see the final color. I purchased Rust-Oleum Painter's Touch Kona Brown spray paint because the cap lid most closely matched the Bakelite color of cabinet. It turned out that the actual paint was much lighter in color than the cap lid!

2. Attach a Spray Grip to the spray can,  such as the Rust-Oleum Model 243546. It will cut down on hand fatigue and "trigger finger" when applying paint (or primer).

3. Always have a paper towel handy to wipe excess paint from the surface of the spray nozzle. This will prevent paint spatter on the applied surface. I wipe the nozzle every four to five spray passes.   

4. Lay the radio cabinet on its back with as little surface touching as possible. I use paint stirrers to raise the cabinet off of the cardboard underneath it. You can paint the majority of the surface exterior with the radio cabinet on its back. 

5. If possible, paint outdoors in direct sunlight with the cabinet raised about waist level. This will give you easy access to all of the surfaces that need painted and allow you to carefully inspect your work in the bright light.

6. Do not try to paint the entire radio cabinet at once. First apply a light dusting of paint on the surface and then gradually apply more coats, taking five minute breaks between coats, until the radio cabinet is completely painted. This will prevent drips and sags in the paint job.

The Finished Product

The paint job turned out better than expected. The only downside is that I didn't take my own advice and test the paint before applying. The brown is much lighter in color than the original Bakelite.

I have decided to keep the radio cabinet's new light brown color.  All that needs to be done is reinstall the electronics and the radio will be ready to go!