Techtip18

SAVVA Technical Tip No. 18

Repairing Bakelite

Basic content extracted with thanks from CMC newsletter

I thought I would pass along this good tip concerning the patching/repairing
or making of replica Bakelite parts – try using Bowling Ball Compound. This is a
two part thick liquid – Varithane or Urethane, mixed at three parts compound to one catalyst.
It takes about 24 hours to become completely hard. If you want to colour it – say black or brown –
simply mix in some common pigment used for epoxies. Plastic or/and glass fibre. Suppliers usually
carry a wide variety of colours. If wear resistance is required – say to repair the broken check of
a slipring on a magneto – add some dry brick dust to the mix. This dust is called an “extender.”
If you have Diatomaceous or Fullers Earth handy it can be added to the mix instead of brick dust.
Brick dust can be obtained by drilling into a brick with a masonry drill and screening the dust
through a fine tea strainer.

One can even use this Bowling Ball compound to create replacement parts using silicone rubber moulds
with brass or steel threaded inserts where needed. Please note, parts to be repaired must be absolutely
clean prior to repairing. This process could be invaluable if you need a “one-off” part. Repairs or new
parts made from this compound are as tough as a bowling ball – enough said. There is a gentleman who
uses this process to make high tension magneto pick-ups for obsolete magnetos and his parts are as good
as the originals – if not better.

p.s from Eric McQuillian

It would be interesting to see how this product works on Bakelite products of 50 years ago i.e.
car window surrounds, cameras, radio cabinets, appliances etc.