by Phil DeMayo <flip1948@[EMAIL PROTECTED]
>
May 20, 2008 at 08:20 PM
On May 20, 8:17=EF=BF=BDpm, Frank Provasek <fr...@[EMAIL PROTECTED]
> wrote:
> A brief dipping is impossible to tell for sure. =EF=BF=BDMints clean
blank=
s in
> acid to brighten them after they are heated (annealed) to soften them
> before
> striking. =EF=BF=BDCoin dips like Jewel-Luster =EF=BF=BDare weak
sulfuric =
acid
> (stronger than lemon juice, not as stong as acid-stomach) and generaly
> will not
> harm a coin if used properly on a coin suitable for dipping (not
> copper, and not with heavy tarnish)
The active ingredient in these dips is acidified thiourea, usually
about 7%
Tarn-X contains no sulfuric acid (less than 1% citric acid, less than
1% Hydroxyacetic acid and 3-5% sulfamic acid).
E-Z-Est coin cleaner (formerly Jeweluster) does contain a couple
percent sulfuric acid in addition to the thiourea.
