To any and all: I want to do some etching on copper, silver and
perhaps brass. I have heard that ferric chloride with citric acid is
a safe method to etch on metal. I have breathing issues and do not
want to compromise my breathing. I was assured that ferric chloride
is more of a safe product than others out there. Does anyone have
experience using this product and/or the combination of the two
products? How safe is ferric chloride? Is there a safer alternative?
Where might I get ferric chloride and how much do I need for small
projects which might include bracelets and earrings? Additionally,in
looking for a safe product with less caustic quality for a flux, I
bought a small container of Firescoff. Do I need to use any other
products (other fluxes) with it? Do I need to use my vinegar/salt
pickle when I am finished soldering?
I’ve been using ferric chloride with citric acid etchant solution for
quite while and found it a safe way of etching brass. Of course I
would advise you to use a mask, safety glasses and rubber gloves. Is
important to remember although ferric chloride it is safe, it is a
“corrosive poison” so avoid contact with eyes and skin and use with
adequate ventilation. You can find all you need at
Ferric chloride is a relatively easy process for etching copper. It
will etch copper all by itself, the citric acid is added so that you
don’t have to constantly stir/shake or bubble the ferric chloride
solution to remove the build up on the copper surface. You can
purchase Ferric chloride at Radio Shack, a bottle costs about $10
usd, it is used to etch circuit boards.
Unfortunately you’ll need nitric acid to etch silver.
From the MSDS (http://www.ganoksin.com/gnkurl/1i9), [ferric
chloride] is toxic to lungs, mucous membranes. But this is for
the chemical itself. The reaction isn't violent or fuming in any
sense, but dust from dried ferric chloride is harmful to your
lungs. Since your lungs are already compromised, I would wear a
good respirator and not leave it to chance. Goggle and gloves are
also in order.
The solution does become highly acidic after the reaction, so
you should have some baking soda on hand to neutralize any
spills, especially on your skin or clothing.
I recommend you look into electro etching. The electrolyte solutions
are reusable and last forever. Ferric Chloride gets saturated with
copper salts and needs to be disposed of through a hazardous waste
handler. There is a wealth of on nontoxicprint: http://www.ganoksin.com/gnkurl/1ii, and if you are more kit oriented
a friend of mine has had good results with Sherri Haab’s E3 kit: Etching – Gingerline
Hi Barbara: Copper can definitely be etched away with ferric
chloride. Citric acid, vinegar, and salt are unnecessary. In my
previous days as an electronics hobbyist I have made electronic
circuits by using ferric chloride to etch awayexcess copper from
copper-clad circuit board stock. Ferric chloride can be found in
some Radio Shack storesor on Radio Shack online, at concentrations
that are usuallysafe enough for common use. Definitely do not drink,
and handle with latex gloves. Keepaway from metal. You can generally
re-use the solution several times before needing to dispose of it.
To dispose, mix onecup spent solution to one gallon fresh water
before flushingdown toilet. Ferric chloride should be effective with
most copper compoundssuch as brass. I myself have not etched silver,
but have read that only ferric nitrate is effective for that. It is
much harder to obtaindue to increased regulation of most chemical
supply houses,but some other member can steer you in the right
direction.
I have used ferric chloride for etching copper circuit boards. You
start with a copper plated fibreglass sheet, apply a resist, drop it
in ferric chloride and after a while you have a circuit board just
like the one inside your phone (almost). This should be a similar
process to what you are looking for.
Where to get it - assuming that you are in the US, try Radio Shack
in what remains of their components section. From memory it is not
too expensive. Otherwise a store which sells electronics stuff to
hobbyists
If you want more on using it, there will be plenty of
on the web for circuit board etching.
Regarding adding citric acid. No idea. I would try it straight
before cocktailing. If you want it to act faster, heat it slightly.
Regarding safety. Don’t drink it, but I do not think it is too
dangerous. I do not remember my bottle coming with a 90 page list of
warnings. I don’t remember it bubbling or making gasses. I think that
the ferric chloride just changes to copper chloride. I think the
instructions on my bottle said to dispose of it by pouring it down
the sink.
The biggest safety issue I know of with ferric choride is it stains
like something which will mean you will cop endless amounts of flack
from your significant other if you spill it on anything you ever plan
on using again. Get yourself some surgical gloves. It didn’t seem to
damage my skin, but took several days for it to wear off.
Hi Barbara, In answer to your etching question - Ferric Chloride is
used for copper and Ferric Nitrate is used for Silver. Both are acids
and are toxic but safer to use then Nitric Acid - and should be
covered when etching and used in a well ventilated room. When using
Ferric Chloride with Citric Acid, which is called the Edinburgh Etch,
you must first mix up the Citric Acid solution - 3 parts water to 1
part powder - then blend 1 part citric acid solution into 4 parts of
ferric chloride solution. The Edinburgh Etch technique is said to
etch copper faster than using ferric chloride alone. Ferric Chloride
solution must be neutralized with washing soda or baking soda, sealed
in a bottle and disposed of through Hazardous waste authorities in
your area. Ferric Chloride solution is neutralized with sodium
chloride and disposed through waste authorities. You can order these
acids through Salt Lake Metals, or the Science Company. Hope this
helps.
I am not an expert etcher, so I won’t try to answer your questions
directly. Instead I will refer you to Relief Etching for Jewelers
and Enamelists by Coral Shaffer which has helped me a great deal. The
book is fairly brief, and to the point. She discusses what works, how
it works, and the health concerns of various methods.
Ferric chloride is a corrosive salt solution that effectively etches
copper. We used to etch the metal in straight ferric chloride with
the image side floating upside down so that the salts would fall out
of the incised lines as they were corroded or etched. If the salts
are allowed to clog the lines they effectively slow down or stop the
etching process. That explains why we etched upside down. Since it
was discovered that adding citric acid to the solution causes the
copper salts to be held in suspension in the liquid, clogged lines
are not a problem and the image etches quicker and cleaner. Proping
your metal on edge rather than laying it flat on the bottom of your
container is the preferred method… Once you have made your etching
solution, keep it covered and, with the exception of evaporation, it
should remain effective for a year or more with moderate personal
use.
When ready to dispose of it you will need to add baking soda untithe
solution no longer fizzes. Label the solution "contains copper"
before turning it in to your hazardous wast disposal agent. The
danger is the copper, not the neutralized ferric chloride. Copper
kills fish. Don’t pour it into the water system… The non-toxic
printmaking movement hailed ferric chloride for not having dangerous
fumes, but they did not look at it from a metals perspective. The
fumes may not be hazardous to you, but they are corrosive to metals.
Keep a tight lid on your container. I have used the same Tupperware
containerfor etching and storing Edinburgh Etch solution for over
ten years, just changing the solution. Google non-toxic printmaking
for more and the recipes for Edinburgh Etch (ferric
chloride with citric acid) which vary for copper, zinc, and steel.
M. Quinnan Whittle
Copperplate Etchings and Jewelry