you are doing this backwards - (are you unpotting an NST? if yes, check the
tesla list archives) - put transformer in freezer (or better yet liquid N2)
and get it really cold, then take it out and tap the tar with a hammer - it
will just shatter like glass - get most of it off that way, then use
solvent - others have suggested proper solvents



"Jon Danniken" wrote in message
...
Howdy,

I need to dissolve some asphalt potting tar off of a transformer (metal
content). In the past when I have done this, I have used gasoline, which
does work. The usual technique is to put the unit in a bucket of the
solvent and let it sit for a few days, brush off whatever is soft enough,
and repeat until a sufficient amount of tar is removed to allow access to
the innards.

Now, however, being somewhat more cautious, I am entertaining thoughts of
using a less volatile solvent, in the interest of safety. Ideally, I
won't be giving up too much solubility in the process

I have narrowed it down to a few choices, diesel, kerosene, naptha
(Coleman fuel), or paint thinner (mineral spirits). Diesel would be about
as cheap as gas, which is a plus, but I am unsure as to it's ability to
dissolve tar.

Any thoughts on which would be the best solvent for dissolving asphalt
tar?

Thanks,

Jon




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