[MR] Any Brass Etch'ers out there?

[rmhowe]

Siegfried Sebastian Faust wrote:
> 
> I'm trying to etch some brass, and having a few issues I'd like to talk to
> someone about.  Anyone on the list an experienced etch'er?
> 
> Thanks,
> Siegfried

Hi Siegfried, 

Clean your metal thoroughly with pumice and a toothbrush
until water will sheet across it. Being a bit of a cripple
I cheat a bit and use fine sandpaper instead. The metalsmith
teachers I know use pumice. As long as the water sheets -
no difference. Pumice may be had at the hardware store in
the paint department.

You can use asphaltum that you may obtain at a paint store.
When it dries scratch your designs through it with a metal
stylus. It will come off with paint thinner / turpentine when 
you are done.

Alternately you can paint the parts you do not want eaten
away with any enamel paint, say model paint in little jars
if you like, or even a spray can over a stencil.
I generally like paint better. I have asphaltum also.

Go to Radio Shack. Get some PC Board etching solution.
Works on Brass, Bronze, Copper.
It won't eat your hand. Follow the directions.

Submerse your item (remember to coat the back) in a plastic
or enamel tub, preferably at an angle, wave a light feather
over it frequently to displace the bubbles that are forming.

Wash thoroughly when finished.

You can use liver of sulphur or (black) spray paint to darken
the etched background. Use latex gloves and a face shield
or goggles. Use a light grade of sandpaper to take off the
higher areas, carefully leaving the back dark.

There are photographic processes involving a photochemical
solution from Kodak, which also requires a high, or long
exposure.

Julie Shea-Graw who teaches metalsmithing at Meredith College
in Raleigh has a photo-exposure method to make small silk screens
for jewelry work. The resist is still asphaltum. A set up would
cost you about $150 and I can't say it's all that spiffy.
It's for production work for small metalsmiths.
I think Rio Grande sells it. http://www.riogrande.com/

There is also a process involving ironing styrene from a high 
contrast transparency to the metal hinged on one side to the metal.
The metal sits on an upside down iron, and you pet it on with
a leather glove. I meant pet just like I said. The iron can be
clamped in a vise or held upside down with a board through the
handle. 

The styrene side must be down and it will transfer. You can lift 
up the hinged sheet to check your progress. This requires touch-up. 
The styrene from a xerox, but preferably a transparency
will melt onto your metal (or wood if you are a carver).
It's clean. The whole process is laid out in Tim McCreight's
Complete Metalsmith (usually less than $20). Remember to turn
off that iron. I think the setting is for linen but I could be
wrong.

Personally I would seal my work with a spray shellac.
A light coat from a distance at first. So any paint 
you leave in your grooves wouldn't run. This would keep it
brighter for a longer time. They make a special spray for
this called Stay-Brite. It might be a little more resistant
to the atmosphere. It's generally obtainable from woodworking
supply catalogs like http://www.rockler.com/  .

I have done -all- the above.

Silver and some other metals requires nitric acid.
Stick with the brass for a while.

Magnus