Some treasure I found
When I pass through towns on business or when shopping for normal household and workshop needs I stop in charity shops because for upcycling, recycling and just plain good finds at a low cost you can’t beat them. In a nearby town I happened into one and wandered the mass of mixed goods. I found a nice Victorian chest of drawers in mahogany I had been looking for and then my eyes passed over an old plastic door knob that was little unusual. I bought it for 50p. The chest of drawers cost me a lot more. I’d been looking for door knobs since I mentioned the twin use you could put a plane-iron screwdriver to a few days ago (See here for more). In a matter of half an hour you can take a knob like this and upcycle it, which is what I did. Here’s how.
Firstly, I knew I had some ferrules so I could size the diameter I needed as a capture ring around the main stem I would use for the screw-driving part. I know some plastics to be brittle and would not on its own hold up to the torque needed for cinching the setscrews tight on plane irons. Keeping the square shaft inside meant the plastic would not be relied on at all as I could cut a slither from the metal shaft to receive the plate steel that would drive the setscrew. This plastic knob was extremely brittle but I could see attractive possibilities too.
I used a mixture of rasps and files to reduce the diameter until the ferrule started to fit. Additional filing worked just fine and soon the ferrule fitted in diameter and also seated against the sawn shoulder line too.
I cut two parallel cuts side by side to remove a section from both the plastic and the square shaft to receive the steel plate, leaving enough protrusion for the plate to register in the slotted screw head. With judicious cutting the steel plate can be sized to sit below the rim of the ferrule so that the brass rim encloses the setscrew and turn one way or the other registers the plate in the slot.
Mix some epoxy glue to hold the square shaft in place in the handle. Most plastic handles are hollow and the top can often be removed. If not you must run the epoxy in the shaft before inserting the shaft. This will force the glue back up and around the shaft. I used 5 minute epoxy so it was already gripping by this point.
Tomorrow, when the shellac has cured and is hardened off I will buff it out and apply some furniture wax.
Take care with the plastic doorknobs you choose; some bakelite plastic might contain some level of asbestos. Whereas some bakelite items were made using asbestos––those associated with electronics for electric components needing heat resistance for instance––others used perfectly safe wood fibres as a filler. Whereas it is likely that no plastic is altogether safe, it’s probably a good idea to avoid bakelite as you have no way of knowing the content in manufacture.