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-   -   Varnish on old transformer (http://www.diyaudio.com/forums/tubes-valves/123217-varnish-old-transformer.html)

duderduderini 17th May 2008 11:23 AM

Varnish on old transformer
 
Hey Guys
I just bought 2 240 volt to 110 Volt transformers so that I can run a balanced 240 V out to my equipment by connecting one winding of each to the other etc etc to get 240 V out.
These transfromers made by A and R australia in the 60's. Brand new as in I cracked the wooden crate and then removed the bitumised paper wrapper and the the other wrapper.. so in effect pristine.
My question is though that the varnish odour is quite strong... and I am wondering what the likelihood is that this varnish contains PCB's. It will be a pity to ditch them if they are as the balanced isolated AC works for my ears.
So do I worry and ditch them or just take a deep breath?
Thanks
Nick

Eli Duttman 17th May 2008 11:42 AM

PCBs are not highly volatile. What you are smelling rates to be some solvent, not PCBs.

Protect the trafos from dust and let them air out for a few days, in a well ventilated space. Then, put them to work!

duderduderini 17th May 2008 11:54 AM

Thanks
 
Thanks for that.. They are great trannys rated at 9 amps. I have already back to backed my sound system... With the Balanced ac music is certianly better.
Cheers

Rod Coleman 17th May 2008 01:47 PM

Trafo Oil
 
The PCB (nasty) oil used in trafos is very mobile (runny), and I don't believe it was used in open trafos. The black steel enclosed type with ceramic terminals are most suspect for PCB content.

RaphTube 18th May 2008 09:08 PM

PCB??
 
Hey, I have a couple of the old black jobs you're talking about with the ceramic terminals. What is PCB? I've never heard of it before. -sounds very nasty. should I be worried?

Colt45 18th May 2008 09:52 PM

I thought they were only used in big huge transformers, something the electric company would use... not small consumer trafos.

Rod Coleman 18th May 2008 10:08 PM

Polychlorinated biphenyls Oil
 
PCB oil was used in chokes, transformers, and oil-capacitors - and it is very likely that ex-military purchases of sealed items of good valve amplifier utility will include this toxic material.

Even small caps down to 2uF/600V used it, and old-design flourescent lighting units also adopted oil caps of this kind. Air forces liked it particularly, since it's nonflammable.

The old black enamelled steel-enclosed trafos are usually well-made, and don't present much of a safety hazard, unless physically damaged.

Making sure they don't leak is the main precaution, so use a fuse on primary and secondary to be sure they don't overheat and spew oil from some rupture of the housing.

Don't landfill dud items of this kind, turn it in to a proper handling agent. Check the precautions for handling the event that leakage does occur:

http://www.hse.gov.uk/pubns/msa19.htm

the nature of the PCBs:

http://en.wikipedia.org/wiki/Polychlorinated_biphenyl

nhuwar 18th May 2008 10:17 PM

pcb's was used as a nonflammable replacement for hydrocarbon dielectric oil. It was not used in varnish or shellac. It was used in enclosed transformers and capacitors. It was not nor could it be used in open frame transformers.

The smell was probably napthane.

Nick

duderduderini 19th May 2008 06:18 AM

definitely not pcb
 
Hey there.
Being a civilian type step down unit, it is an open transformer in a steel case of course. The smell has dissipated greatly over the last few days but it certianly isnt what i would call a pleasant smell...
Hopefully it will have completely gone in the next few days.
Thanks for all the help
Nick

Nordic 19th May 2008 09:27 AM

It is probably just from being packed that well in storage....

Even new transformers I have custom wound at the factory stink to high hell for the first few weeks...


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