Somewhat OT - Transformer oil

I did do a bit of research into this when I realised that I needed to top up my old BOC Oxford set. I discovered that the machines were originally filled with 'Diala B' from Shell and this is a high dielectric strength low vapour pressure mineral oil - the spec sheet is available on the net if you want to Google for it (545 hits for 'Diala

+B oil' (no quotes)). As far as I can tell it has never been anywhere near a polychlorinated bi-phenyl. Why anyone would ever want to tip nasty crud like that into a poor harmless little Oxford set is beyond me.

I was offered some Diala B by a Birmingham based welding supplies outfit. Morris Lubricants of Shrewsbury said "Diala B? Oh, yes, that'd be our Transformer Oil...", available in 25-litre drums at a price.

The primary purpose of the oil in an Oxford set is to cool the set, not to insulate it, so the high dielectric strength of Diala B is just a bonus as far as I can see. You could probably fill it with chip fat without adverse effects if you felt that way inclined.

Safe? Well, I doubt I'd want to drink any, but I'd be happy to get my spanner out of the bottom of the welder by hand if I had to, if I turned it off first.

TTFN

Pete

I don't think anyone here has ever suggested that they've done so, or have I missed something?

Cheers Tim

Just to add what Peter Scales has already said, the Shell Diala oil conforms to BS148 which covers mineral insulating oils.

There are no PCB's (PolyChlorinated Biphenyls) in this oil, and PCB production was halted in 1970 by all accounts:-

PCB's were made for high-voltage insulation purposes, and as far as I can see they were never used in low-voltage equipment. Most of this stuff was taken out in the 1970's, certainly by the early 1980's you couldn't lay your hands on anything near to it.

If anyone has anything else in the way of info I'd like to see it, just to add to the knowledge base.

Peter

-- Peter & Rita Forbes Email Address: snipped-for-privacy@easynet.co.uk Web Pages for Engine Preservation:

Back in the salad days of my youth, I worked for a high voltage capacitor maker, and we used Diala B for impregnation of the lower spec capacitors. I can categorically state that having spent six years working with the stuff, Diala is NOT PCB, nor does it contain any PCB and never did. It is a common or garden mineral oil.

The most widely used PCB that I'm aware of in the capacitor field (used until early 70s) had the trade name Araclor. If you're offered a barrel of this, politely decline.

Regards, Arthur G