Thread: Etching
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Ed Huntress Ed Huntress is offline
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Default Etching


"Jedd Haas" wrote in message
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In article ,
"Ed Huntress" wrote:

"Joseph Gwinn" wrote in message
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In article ,
"Ed Huntress" wrote:

"Joseph Gwinn" wrote in message
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In article ,

Ferric chloride is not volatile (won't evaporate), is easier to
control
and is safer, and for those reasons is a standard etchant for steel.

Joe Gwinn

How does it bite, compared to nitric? Does it undercut? Do you have to
etch
in multiple bites?

I've never used Nitric Acid for etching, so I cannot offer a
comparison.

I've etched carbon steel (1095) and high-carbon stainless steel (like
440C) with wax resist and a cotton swab soaked with concentrated ferric
chloride solution at room temperature, sweeping over the area to be
etched manually. I don't recall how deep it went, but it was not
superficial. I recall it taking ten or twenty minutes total, but I was
talking as I did it, so I wasn't keeping score.

Joe Gwinn


Thanks. If anyone has compared it with nitric acid, I'd really like to
know.


I've used nitric and ferric chloride for etching copper printmaking
plates. The main difference is that the nitric dissolves the metal and
it's mostly gone, while the ferric leaves residue in the bite. For that
reason, it's helpful to etch upside down in ferric so the residue falls
away. (Prop up non-etching areas of the plate on some small plastic
blocks; you might also want to rinse your plate and brush off residue
from time to time.)

For copper, the best etchant is dutch mordant (hydrochloric acid +
potassium chlorate). Unfortunately, it's both difficult to obtain and
rather dangerous. The ferric is the least dangerous of the three. The
ferric also has a rougher bite than the nitric. The results can also
vary quite a bit depending on the acid strength, both the original
dilution amount, and the amount of etching time you've used it for.

Also, regarding the resist, check out some printmaking suppliers. The
"hard ground" they sell is a brush-on resist that's thin and easy to
draw on, it's also easy to remove with solvent. Try Graphic Chemical and
Ink in Chicago. The hard ground will be easier to use than beeswax,
particularly if your design has any fine detail.

--
Jedd Haas - Artist - New Orleans, LA
http://www.gallerytungsten.com
http://www.epsno.com


Thanks, Jedd (and Don). Have either of you ever tried it on steel?

I've used it on copper circuit boards but this is the only place I've heard
of it being used for steel. I've done some etching in steel with nitric
acid, a couple of decades ago, and I learned that you have to use several
bites to prevent severe undercutting.

I'm curious both about the speed of ferric chloride in steel, and the way it
cuts -- undercutting or not.

--
Ed Huntress