Removing knobs that have been glued on...

[RetroHacker]

I just picked up a GE console radio, 1940-ish. It's in pretty good shape, all considering, and it was obviously worked on at some point - the speaker is missing, replaced with a Realistic bookshelf speaker sitting in the cabinet. The wires leading to the speaker and to the antenna are modern plastic covered type, and the grille cloth has been replaced with burlap. The knobs look like generic plastic replacements, one of which has a chunk broken out of it. After removing the speaker and beam-o-scope antenna, I removed the bolts holding in the chassis, and went to pull the knobs off. They wouldn't come off. Checked for setscrews, but these are clearly push-on type knobs. The usual pulling, wiggleing, etc. would not budge these knobs. Someone had superglued the knobs onto the shafts!

So, I thought about it for a while, and came up with a solution. Here's how to do it, should you run into this.

Assuming that it is safe to put the pressure on the inside of the cabinet of your radio, remove the bolts holding the chassis in and slide the chassis all the way forward, exposing as much of ths knob shafts as possible.

Take a thin piece of cardboard (like the cardboard from a cereal box) and cut a comfortably sized rectangle, about the size of an index card. Then, cut a slot from the middle of long edge of the rectangle to the center of the cardboard, and cut a hole at that center point about the size of the control shaft. This will allow the cardboard to fit over the shaft and sit flat against the radio, the slot oriented to the left or right side. The purpose here is to protect the face of the radio from the next steps. You want to be sure that the slot you made will be oriented to the left or right (left if you're right handed, right if you're left handed). It might help to leave the bottom edge of this cardboard a little longer, or tape a penny to it to weight it down, to insure that it stays oriented how you want it.

Prop the back of the radio up a couple of inches with a book, so that it's tilting toward you. This puts gravity in your favor for the next step.

Take a Q-tip, and dip it into a bottle of acetone (nail polish remover). Carefully dab the q-tip to the control shaft, just behind the knob. You're trying to get a tiny amount of acetone to run down along the control shaft, and into the knob to dissolve the glue. Turn the knob to allow you to apply acetone to all areas behind the knob. It doesn't take much, in my case, I used about three "dips" into the bottle. The Q-tip won't be dripping with fluid either, just wet. You don't want actual drips of acetone - that would be too much. Be careful not to get any acetone onto the front of the radio, or the sides of the knob. In my case I didn't care too much about the knobs, they were damaged and non-original. I didn't actually wind up damaging them, however.

Pull firmly on the knob, wiggle it, and it shoud come off. Don't let the acetone sit too long and dry. Pull right away. I tried after one "dip", and it was still stuck. Two more did the trick.

As soon as you get the knob off, clean the shaft and wipe off any extra acetone. I rinsed the knobs out in the sink to clean them. I discarded my scrap of cardboard and made a new one for the second knob, since it was had gotten a bit of acetone soaked into it, since I used such thin cardboard (cut from a the package from a light bulb).

This method worked very well for me in this case, with no damage to the knobs or to the radio's finish. I would advise extreme caution using acetone anywhere near a radio - it dissolves plastic and removes paint. But that is exactly what you need to dissolve super glue. And be certain that the knob you're removing actually is a push-on knob that's been glued, not a knob with a setscrew.

-Ian

[crewbus]

Just wanted to thank you, Ive got a grundig that somebody was to lazy to just tighten the set screw on the volume knob so they superglued it on, the acetone worked great, I did'nt have enough room to get it on the shaft so I removed the set screw and put a drop down there, a couple of minutes of pulling and jiggling (man this sounds dirty) and it popped off,

Thank you!