I was curious I believe that sulfuric acid is "pickle" and used in
etching and is used in car batteries. Is the sulfuric acid out of
an old car battery too contaminated for use in jewelry?
Possibly not, but getting it out of the battery safely would be a
problem. I use battery acid as pickle, but I buy it from a local auto
parts store. Here in Memphis, a 6-qt container of 65-per-cent
sulfuric acid costs about $12 USD. I have had no more problem with
with diluting battery acid than with using Sparex or pool chemicals.
Diluted 4:1 with plain water, the result is 14.9-percent, and 5:1 is
12.14-per-cent. A standard mixture of Sparex is equal to about
12-per-cent acid. I usually mix mine a little on the "hot" side.
I do take a little more care with liquid acid. I typically wear
latex gloves, and a denim apron. My sleeves are rolled well up. I
wear safety glasses, so I usually don't use goggles or a face shield.
I dilute the acid near my sink, and have an open container of sodium
bi-carbonate nearby. I know that some on this forum would recommend a
full shoulder-to toe rubber apron, high rubber gloves, rubber boots
and a full face mask, and all work done under a fume hood to dilute
acid. I believe that the level of protection which I choose is
adequate and practical. Go to an automotive battery shop, and
observe the level of protection used by the mechanics. Sometimes they
will wear gloves and some type of eye protection, but usually not,
and usually no apron of any kind.
I will decant 65-per-cent acid into a beaker in the amount of
one-fifth (or one-fourth) the volume of my pickle pot. I then put
the remaining 4-fifths (or 3-fourths) water into the cold pickle pot.
I then slowly add the acid to the water in the pot. A quick stir with
a plastic spoon and the pickle is ready to be heated. All this taking
the reasonable precaution of working carefully. Clean up afterward
so no stray drop of acid can get on clothing later.
As an additional benefit, using 65-per-cent acid is cheaper than
either Sparex or pool chemicals, and doesn't have the "goo" that I
associate with Sparex.