Fw: Help Brighten Bronze

[w gottesman]

----- Original Message ----- From: w gottesman To: sundial@rrz.uni-koeln.de Sent: Thursday, September 05, 2002 11:33 PM Subject: Help Brighten Bronze Hi all. I need to brighten the dark patina on my large bronze focusing dial for a photoshoot.    I do not want to use anything abrasive, especially because I do not want to accidentally scratch the mirrors or abrade the cast bronze surface.  I have tried Tarn-X and muriatic acid.  Both brightened the dial surface very quickly, but just a few minutes later the surface would darken intensely, despite copious rinsing and even trying a light wash with baking soda.  Household ammonia was worthless.  Nevr-Dull cottony material works OK but slowly, and I go through the stuff pretty quickly.  It has a mineral spirit/wax base, but I don't know what the actual reducing chemical is.  If I knew, I could try to make a recipe that might suit my needs a little better. Does anyone on the list have a favorite non-abrasive method for brightening bronze (or brass)? Bill Gottesman