So, not one of these ... ... one of these First, a soak for the threads in this stuff. Half-an-hour for this application is sufficient, not overnight or days - it’s thin oil and capilliary action in the threads gets to work pretty quickly when they’re not gummed-up or bonded with rust (they’re brass). Nevertheless, the bond is tight and I wasn’t messing about with anything puny to do the unscrewing - not for the faint-hearted. The slivers of viton sheet are packing for the pipe wrench jaws to prevent scoring of the brass spindle or bakelite knob. It’s a torque/leverage thing, but the heftier of the wrenches (the Knipex with the red handles) was best to grip the spindle, using this part of the jaws nearest the fulcrum. Thus. Enter the other wrench to grip the knob. ‘Lefty-loosey’ and the knob unscrewed. I was aware the packing washer was shot, hence the procedure to get at it. With the knob removed I used a white paint marker pen to pep up the lettering on it. The component’s off a Bialaddin MkI bowl fire I’m restoring. Nearing completion, I’ll feature it in the Lamp Reference Gallery soon. John
Add Without the flat on the spindle and in the bore of the control knob of later components, the ‘timing’ of the knob arrow with the ‘up’ or ‘down’ movement of the pricker eccentric relies solely on Bialaddin’s factory setting of where the screw-on knob comes to rest on the threads. I found that screwing the control knob on as tightly as it would go resulted in the correct timing.
Yeah they're a pain to get off. I normally just wrap some Teflon tape around the spindle to seal the gland if I can't get it off to replace the washer.
