Upcycled Door Knob Makes a Plane-iron Screwdriver

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 marked the inside of the ferrule onto the plastic as shown.

I got my distance from the end of the knob using my thumb and finger as a guide. Running the pencil line around the outside gave me a cutline.

In my case the depth was under an ⅛” and I used a fine model saw to cut the shoulder line where the ferrule would seat.

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 a section of steel plate for the actual driver part with a hacksaw.

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.

I used superglue as a temporary hold and to seal the gap around the shaft in the plastic knob. You must cut the shaft to a suitable length.

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.

I polished the brass ferrule on a buffing mop on an electric grinding machine but you can just use a strip of leather charged with buffing compound.

The ferrule was snug enough but a little epoxy on the inside of the ferrule secured all the elements together.

I used three coats of shellac to brighten up the plastic and that works as it does on wood.

The sizes are all taken from the setscrew. I allowed and extra 1/8″ in diameter as there is no need for any dead sizing.

 

Tomorrow, when the shellac has cured and is hardened off I will buff it out and apply some furniture wax.

Warning:

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.

6 Comments

  1. Glenn Malone on 19 December 2016 at 11:15 pm

    Hi Paul,
    Could you explain how you remove the sliver of metal from the metal shaft please? This will be a nice little project between Christmas and New Year.



    • Paul Sellers on 20 December 2016 at 8:30 am

      Well, if you look closely I just sawed through to the threaded hole used to secure the knob to the bar. I think there is so little metal there that you could use the set of the teeth to side-swipe the waste though.



  2. Jeremy on 20 December 2016 at 12:52 am

    Ha! I thought to myself when I saw the stocking stuffer post you would come up with a self made verison. It’s fantastic. We don’t have cool knobs like that in the US that I’m aware of.



  3. Paul Sellers on 20 December 2016 at 4:32 pm

    Yes, but many other plastics will work just fine and we know that wood would generally be best.



  4. John on 22 December 2016 at 3:06 am

    My son has those hexagon knobs in his pre war house with a need for five sets, I made an exact copy from oak. First planed to hexagon then turned on my lathe to get rounded end and concave to opposite end……..also made deco face plate from oak cut to 1/8″ thick…..stained to give exact match.



  5. Steve on 1 August 2018 at 10:57 am

    Good idea Paul. I made one out of some brass tube and a brass door knob.