Michael
You are right about warming the ferric chloride, it reminded me of a setup I
used to use in making prototype printed circiut boards. Using a small glass
aqaurium, and an aquarium heater and an air bubbler to keep the solution
agitated. I made many prototype printed circuit boards with that equipment.
In addition, the masks I generated were on drafting vellum using black tape
that can be purchased at a drafting supply house. Once this is done, the mask
can be photographically reduced by a shop that does printed circuit work, and
transferred to brass for etching. I had forgotten the trick of warming the
solution, and so I didn't even use this for the dials I etched! It would have
greatly improved the depth I had gotten. Oh well....
As for coloring lines that have already been etched or engraved, when I
engrave a sundial I use a fluid called Gravoxide. This will blacken the raw
brass very quickly, while not penetrating any brass that is covered with
laquer or some other type of mask. I have purchased Gravoxide from the Hermes
company, an outfit that sells engraving supplies. A 4 ounce bottle from them
was about $4.00 several years ago. I bought three just to meet their minimum
purchase amount, and have not yet finished the first bottle. The result is
very fine black lines on polished brass. One thing I have changed though is
that rather than using polished brass, I sandblast the brass instead. It's
much easier to do, and when new it really sparkles in the sunlight! Also, the
dial is much more readable on partly sunny days, as the contrast is much
better than the highly polished finish. I almost forgot, New Hermes Company
is located at 20 Cooper Square, New York, NY 10003. I reached them at (800)
8HERMES, if that helps.
Steve
