Bringing New Life to an Old Tube Radio




Introduction: Bringing New Life to an Old Tube Radio

About: I love building things, and I'm a twin, we both are electrical engineers and inventors. Feel free to ask anything else

I recently purchased a 1950 Arvin AM/FM tube type radio from an antique store. the radio wasn't in too bad condition for its age and after testing it before i bought it, the radio sounded great and everything worked on it (except the FM side, but thats for a later instructable). so i splurged a whole $25 for it and brought it home. the next thing that I decided to do was make this radio have a more updated presentable look rather than the old vanilla color it had, so i went and got some Krylon spay paint because they are known for having good plastic material related paint.

materials i used to do this:
1 roll of masking tape
some newspaper
1 can of Krylon fusion hammered finish (dark grey in color)
1 can of Krylon metallic finish spray paint (bronze w/ metal flakes color)
some toothpaste for polishing
toilet paper for polishing

Step 1: Removing the Chassis

I removed the chassis which was held on underneath by 4 screws, and also the knobs on the front which just pop off with a screwdriver. there appears to have been some updating done to the chassis some time in the past too. it has a polarized power cord, a newer looking speaker, and tuning dial string which these things i know weren't original to the radio. im not sure if the tubes are original or not, they look really clean and light up well. the chassis has no rust or for that matter dust anywhere on it. the underside is all original caps and resisters and fabric wiring. the antenna on the back works great still.

Step 2: Prepping for Paint

now that the chassis and knobs are removed, its time to clean the exterior case and mask off any parts that i dont want to be painted right now. i taped off the plastic lens with the radio frequencies on it and also the brass metal trim on the middle of the radio. I also taped off the plastic speaker grill area to paint it another color. I will leave the huge plastic crack on it because i think it gives the radio character.

Step 3: Paint Exterior Case

after masking off the sections i didnt want to paint, i decided to use the Krylon fusion for plastic paint with the hammered finish look. it gives whatever is painted a look like it is a sheet of metal that has been formed by hammering it into shape. it has a nice realistic texture to it as well. i like it alot because now the radio looks like a metal case instead of that old weak plastic look. im leaving the brass trim and plastic lens covered for the next step which is the speaker grill and knobs.

Step 4: Painting the Rest

after letting the paint cure over night i taped off the rest of the case the next morning to ready the speaker grill for paint. the Krylon paint i used on the casing and for the speaker grill and knobs doesnt require sanding or much prepping to make it stick to the plastic so i was good to go! the paint color i chose for this is the brushed metallic satin finish to give it that older metal look but still be new looking. the knobs i will also paint the same color to have them pop out against the darker case finish. i faced them upside down to protect the brass front on them. since the shaft of the knobs will be inside the radio, i didnt feel a need to clean them up really nice.

Step 5: Results of the Paint Job

after i finished painting the remainder of the radio, i let it dry for a few hours before i removed all the tape and paper. the results came out good, no runs in the paint or blotchy missing pieces. the lens stayed clean and no over spray got on any other part of the radio. the next step was to polish that brass on the face and the front of the knobs. i just used some toothpaste to do this, it doesnt dry to the paint like polish or wax and its dummy proof. just a little bit on some toilet paper rubbing evenly on the metal will do nicely. after i rubbed it on i just wiped it off with a damp piece of toilet paper and it shined up like it was spankin new!

Step 6: Finished Product

after the painting, and the polishing, it is time to put it all back together. i cleaned up the dial face before putting it back in to get any dust off of it and poish the dial too. as you can see now the radio has more than just two colors of off white. the knobs and the speaker grill stand out alot more than before and especially the brass metal finish on it. after letting the paint cure for a few days, its now time to put this thing in the most obvious place in the house and use it! being in Las Vegas, there is some AM stations worth listening to if you like sports and radio disney. this radio is now ready for showing off, and also for football season!



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    10 Discussions

    I expect you will replace the paper capacitors one day and will likely vacuum dust from the blades of the tuner. Some things you wrote hint that you are probably aware of those things, even though you did not mention them.

    4 replies

    yes, although the caps appear fine, i know that they probably dont have their original values anymore so i really do need to change them out.

    I once bought an old Zenith Transoceanic multi-band radio. It worked fine the first time I turned it on. Then I had to replace a capacitor that failed. It worked again. Then another capacitor failed, and so it went until I had replaced all of the paper capacitors. As concerns values, I remember reading that the values of even new capacitors can be off as much as 100 percent.

    Yes, the old paper/wax capacitors do not stand up well to the heat produced in a tube radio. You are lucky they lasted this long.

    As for how far off they can be when replacing, it depends on where they are used...for the large electrolytic capacitors (looks like you have one, vertical round can mounted near the middle of the back) Phil B is correct, they can be replaced with capacitors as high as 100% higher than the originals (but not lower). I try to find ones that are as close as possible to the originals because it makes it easier to identify on schematics if anyone else is working on this radio in the future.

    The paper capacitors are a different story and should be replaced with capacitors within 20% of the original value (again higher than the original value, not lower). This is because the original caps were not manufactured as precise as modern ones...the margin of error was far from what it is now.

    Be careful on voltage ratings...these old radios will have 180 volts DC in some places, so I don't buy anything rated for less than 400V so I can use it anywhere in the radio. A modern cap with the same farad rating is likely not going to be designed to handle this kind of voltage.

    thanks for the info! that will help out alot in the future when i start really digging into this thing.

    You did a awesome job! Jobs that look that good people pay good money for here in Vegas.

    Cracks are easy to fix on these old plastic radios. I've had good luck using super glue. First, glue the crack shut. Then build up layers of super glue in the crack. When the crack has been overfilled slightly, sand it flush with the cabinet with 400 grit sandpaper. Apply paint and the crack disappears. Also, I've found it much easier to simply pop out the plastic lens that covers the dial than taping it off. Plus, while the lens is out, it is easy to polish out any scratches.

    2 replies

    actually, i didnt remove the lens, i just removed the dial and the dial background which were attached to the chassis. the lens was riveted to the plastic and i didnt want to break it off so i taped it.