rebuilding a Calumet C1 - need knob help

[Mark Fisher]

All the plastic knobs are broken and I need to replace them. The problem is they are seriously stuck on the studs (haven't tried the ones that look pinned on yet). I've even broken off the plastic (there is a brass insert unterneath) and tried a propane torch to loosen them up. Any thoughts?

 

[juan]

Go to the auto parts store and buy a spray can of "PB Blaster" - that should penetrate the threads. Spray, knock on the broken knobs with a hammer to set up vibrations, then let it sit overnight.

I've found knobs that will work at my local Ace Hardware.
juan

 

[wa1vgb]

You can remove those very easily with a cold chisel and hammer. Support on a vise or something solid. The brass will split.