oxford oil cooled oil

[oldbikedavey]

Moving things on a bit, I might decide to machine up some 3/8 BSW terminal knob cores today, and then cast polyurethane resin insulation / thumb grips on to them.
Got a chunk of brass that will do well enough for the conductive bit, and can replicate the original terminal form as a mould using either wax or whatever for the mould form.

 

[8ob]

3/8 BSW

Or plastic coat something like this Knob

Bob

 

[oldbikedavey]

All moving forwards, knob cores machined up from something cuprous, but not brass, on account of the chip form, which was distinctly coherent, spiral, and quite gummy.
Knurled the main axis, and will likely cast the hand - grip bit tomorrow.....

 

[oldbikedavey]

Or plastic coat something like this Knob

Bob

Nice thought, but the iron has a chunk more electrical resistance than anything cuprous.
WDS do a good line in Marlco broach replacements, though.....

 

[Dragnet]

New transformer oil is almost water-clear.
It discolours with heat, moisture absorption and metallic contaminants.
We've got through drums of Shell Diala (a high-voltage insulating oil) over the years; currently have an IBC with about 900L of the stuff awaiting disposal if anyone would like an egg-cup full...
A few years ago I dropped a few litres off at a forum member's place in Cornwall, as I happened to be passing
If anyone's really keen, there's an insulating oil dielectric strength tester currently for sale on the bay of evil.

That was me. I recall our conclusion was that if the oil's original it's PCB free, as the welder says on it 'fill with 4.5 gal Shell Diala', which doesn't have PCBs in. The welder's been in use for welding plates to some lintels yesterday, and for some carbon arc brazing. It's great to use, and your help was invaluable in keeping it going - I hope for many years to come!

OP - I know it's a while ago, but I had to weld a new bottom on mine as it was leaking, then I replaced the gaskets with new cork/rubber strips, and added bonded metal/rubber washers under the heads of the screws for added leak security. I made it a trolley as it's jolly heavy, and think it's a great welder. I have a BOC TIG setup that came with it, and I believe the previous owner had the Bantam hooked up as the power source in some way, but I haven't waded through the manual and investigated it yet.