Solvent for dissolving asphalt tar?

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
Reply to
Jon Danniken
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In order of decreasing speed (i.e., fastest first): naptha paint thinner kerosene, diesel
Not all that much difference, though. Go with the cheapest.
Bob
PS acetone would be faster than any of these, but way more expensive. And just as volatile/dangerous as gas.
Reply to
Bob Engelhardt
Umm - Spell Checker told me it was "naphtha", but I didn't believe it. Well, it's right & pronounced naf-tha or nap-tha. Learn & learn.
Bob
Reply to
Bob Engelhardt
Hi, Jon. Are you sure it is asphalt tar? Older transformers I have worked on were potted in coal tar. Asphalt tar will cold flow and will really warm flow and make a mess when your transformer gets warm. Coal tar will not flow until it gets to a rather high temperature. It also doesn't dissolve in anything very easily. I am not sure if this makes any difference to you, but you may be able to Goggle a better solvent for coal tar.
Old radio batteries as well as older auto storage batteries used coal tar for sealing. It is also now considered a carcinogen and you can't get it anymore.
Good question, though.
Paul, KD7HB
Reply to
co_farmer
wrote
Well, I'm not entirely too sure, but it melts at about 250F-300F, and smells like the stuff the roofers use to seal cracks with. .
Jon
Reply to
Jon Danniken
So, you could empty the goo with a drip pan lined with aluminum foil and an oven that will hold 300F for twenty minutes. I have at least one tar brick in the adhesives drawer that I got that way...
Reply to
whit3rd
I guess you are not married.

John
Reply to
John
Gotta quite drinking beer when I read these! I had to clean up the keyboard.
John wrote:
Reply to
RoyJ
Use diesel and prepare to be amazed.
Reply to
jusme
Coleman fuel is more volatile than gasoline.
Reply to
clare at snyder.on.ca
Outside interests are a wonderful thing. Bridge Monday night, concert band Tuesday... I just have to make sure the smell is gone before she makes it home.
Reply to
Joe Pfeiffer
Stoddard solvent.
Note the word *solvent*.
That's its intended purpose.
Harold
Reply to
Harold and Susan Vordos
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
Reply to
William Noble
Sure no science, just age and experience. It seems that things closer together on the cracking tower dissolve or combine easier than things far apart on the tower. Diesel would be my first choice - closer to the tars and asphalts on the tower.
Reply to
DanG
That works? Damn...fascinating! Thanks!
Gunner, who learns something cool everyday.
Reply to
Gunner Asch
It is well to remember that there is no single compound that is "gasoline." Over the years it has changed from a totally petrolium distilate with possibly a littleTEL to a witches brew.
I also used to use gasoline to clean parts, but had some a few months ago that took skin off my hands and nearly removed some of the nails.
I don't thnk the major danger is the volitility, which based on hard starting may even be less than the old (real) "gasoline," but the (toxic?) fumes and danger to your hide.
With naptha/paint thinner/varsol you at least know what you are getting.
Unka' George [George McDuffee] ============ Merchants have no country. The mere spot they stand on does not constitute so strong an attachment as that from which they draw their gains.
Thomas Jefferson (1743-1826), U.S. president. Letter, 17 March 1814.
Reply to
F. George McDuffee
Some of us have a stove/oven in our shops for this very reason... to stay married . I've even got m' own washer/dryer in here too.
Snarl
Reply to
snarl
Use the oven and he might not be....
Reply to
Wes
Aviation gas... They cant screw with that too much. The last time they did was when they went to 100LL. It doesn't leave a smell after it evaporates, just a little lead and it takes the oils out o your skin.
John
Reply to
john
I've discovered over the years that you can substitute lots of solvent ($$) for taking advantage of how the solvents work. What I mean is that when I have a thick goo I need to dissolve, I put a rag soaked in solvent on top of/around the goo, and wrap the rag in plastic or some other way to seal it up from excessive vapor loss. Go away for a little while (you'll learn how much eventually) and when you come back it's a whole lot easier to get off than before. In fact, I have a tub that has a bunch of old towels in the bottom of it. When I need to clean/strip painted items, I put parts in the tub on the towels, previously soaked in acetone or other favorite solvent, then close the tub up for awhile. Come back the next time I feel like working on it, and the paint falls off in sheets with little or no effort. Works the same way for any other stuff that can be affected by a solvent. You can work hard, or you can work smart. Me, I'm a bit lazy.
Reply to
Carl McIver

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