I'd like to get the window cranks rechromed on my 58 Ford, but I can't figure out how to get the plastic knobs off without destroying them. Is it possible to take these off and put them back on?? I thought about buying new ones, prob be cheaper, but they're not available with the white knobs like I have. I don't have a picture of the cranks to post.
Put a pot of water on the stove. Heat it slowly, holding just the plastic knob in the water. As it heats up, try to pull it off the handle. If it's still tight, put just the knob back in the continuously heating water. As the water heats, you'll find the temp that the knob releases from its pin. Be careful here. If you heat up the knob too hot, it will discolor to a chalky look, so it's important to keep trying to ease it loose as the water heats. All this will happen at a temperature lower than boiling....but hot. Don't scald yourself. Try it once on a non-critical part. The plastic is much softer and more heat sensitive than the steel pin so it expands under the heat allowing its release.
The pins usually pull out cleanly. leaving the original bore. For reassembly tap the knob with a bottoming, coarse thread square-ended tap and use a truss head or socket head screw of some kind in its place. I just did this on door pull knobs off an old Firestone heater. They were riveted on place and I wanted to plate the doors, so they had to come off. I've done it often with Ford choke, throttle, heater, defrost or overdrive knobs I was replacing. If you want to re use the original pin, buff up the knob to the desired finish, clean up the knob bore with a drill (carefully), put a dab of epoxy on the original pin and shove it back together. I've never tried to pull one apart that had been removed then epoxied. With the epoxy treatment, the knob might not want to come off.
Thanks for that, damn usefull info. The Tech editor should put this in the archives. Are ya listinin Tuck? BB