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Electro etch copper using salt water

Jewelry Discussion
#1

I’m trying to learn how to electro etch copper using salt water and
an alkaline lantern battery. The first battery died after maybe 90
min of on and off again charge. The piece did etch some, with
striations, and not real deep. Took the battery back to exchange for
a another new battery tested to be fully charged when bought. I
hooked all up again in the same salt water I had used, now with
copper in it. Absolutely NO reaction ofbubbling. Tested the wires and
still showing juice, battery down to around 65% now.

How can a battery show a charge, power being drained, and yet no
reaction? The pieces are roughly 1 1/2" prices of copper.

I’m stumped and need some advice.

Thank you
Brenda

#2

Hi Brenda

I did copper electro etch with salt water in a workshop. The salt
contenthas to be high, where no more water will dissolve in the
water. Second, we used a cotton ball attached to a alligator clip
and appliedthe salt water, swabbing the copper piece. Salt water
etching is not very deep and uses up batteries like crazy. I did not
find the process useful for my needs. I use chemical etch.

Gene

#3

I tried the salt water etch and was dissatisfied with the results. I
have gone back to ferric chloride, beefed up with some citric acid.
Iused to get the citric acid crystals, but don’t bother with it any
more. I just squeeze in some lemon juice and it works just fine. I
get nice deep etching on copper, which I then use to roller print
the texture onto my silver. Alma

#4

I have used ferric chloride for etching copper, brass, and nickel in
the past. A few years ago I switched to salt water and electro
etching for a number of reasons. To begin with, I tried the battery
option but was not satisfied with results. After much research, I
now use a small power source and find it works very well. I etch
large (3"x6") heavy yellow brass plates for roll printing cuffs,
etc., and achieve a nice deep etch for the purpose. I also direct
etch copper.

I highly recommend reading Coral Shaffer’s book “Relief Etching for
Jewelers and Enamelists”. It is packed with on a variety
of methods and related safety issues.

If you are getting disappointing results when others are having
success with the salt water etching, most likely there is some part
of your process at fault. With so many variables, it will take some
effort to find the problem(s). Don’t give up too soon. it does work.

Carol

#5

Brenda -

I’ve done salt water electro-etching with good results, although I
only use this method for silver etching, preferring to stick with my
ferric chloride for copper. I use a rectifier for power instead of a
battery and it works great. I already owned one of these for
electroplating, so didn’t have to buy a new piece of equipment. If
you’re only doing a piece of jewelry here and there, it may be an
unrealistic expense. It is a much less costly method than silver
nitrate for silver etching, though and won’t lose potency over a
short period of time as the nitrate does.

Sandra Graves
St Paul MN

#6

I too prefer a ferric chloride etch, but I have never used citric
acid to beef it up, though I’ve heard it’s better: the Edinburgh
etch, I think? Couldn’t find citric acid crystals, and - like an
idiot - never thought about using lemon juice (duh!) Would bottled
lemon juice work, does anybody know? Or would the sulphides used for
preserving the juice interfere?

Janet

#7

You can get citric acid at the grocery store or Wal-Mart. It is used
for canning tomatoes. I got mine at the local health food store, but
that is just because I happened to see it on the shelf while I was
there for something else.

#8

I don’t know about using bottled lemon juice. I just grab a lemon
and give it a squeeze. If you think it needs more of aboost, just
add some more juice. Alma

#9

Regarding sourcing citric acid: I’ve found citric acid crystals at a
local brewers/wine makers supply store. Here it comes in 1#, 5#, and
25# quantities.

John
Keep Calm and Hammer On…

#10

For electro and chemical etching, check out

She has different methods of etching, one is using uv film. There is
a comparison of methods, uv gives deeper and most detailed etch.

There are video demonstrations. I saw the comparison pieces in
person, electro etch with uv film is far superior if you need really
detailed designs.

#11

I’m still working with learning electro etching. I’m encouraged to
hear that others find it successful. I’m figuring my mistakes as I go
and like the feedback here. Batteries and Bulbs did replace the
battery, tho reluctantly. The last time I tried I got current. I
realized my error was rather dumb. I had the piece ready for ferric
chloride etching, so i had packing tape all over the back. Duh! So
wire did not contact the copper piece.

I"m going to set up and try again and again.

thank you
brenda muntz

#12

Most stores that have a bulk section have citric acid.

Also, Hispanic grocers have it in the inexpensive spice section.

Laney
Silentgoddess

#13

Hello Orchidland,

I have used citric acid pickle for many years. I bought the stuff
online from a website that provides ingredients for soap and bath
bombs. 10# lasts avery long time!

Judy in Kansas, who has just enjoyed her 50th High School reunion.
At first, it looked like a crowd of old people, but before long each
one became a remembered classmate. My advice - make the effort to
join those reunions. Tomorrow is promised to no one, and someone
wants to see you again.

#14

I have been teaching galvanic etching for several years now and am
having great success in my classrooms. We use a copper sulfate bath
for etching copper and copper alloys and copper nitrate for etching
silver. Other than having to occasionally strain the sludge from the
bottom of the container (I use a coffee filter in a funnel) and
rarely adding some copper sulfate or nitrate (when needed) I can use
the same bath for years and countless etchings.

I also find batteries expensive and find them environmentally a
problem, so I have use a small 30V 5A rectifier. These are available
on ebay for about $65. For the attachment to the anode, you can tape
copper wire on to the back, solder it on or drill holes in the
corners of your work and make hooks on the ends of the wire to hang
the piece. We usually use a full sheet of copper for the cathode and
just bend over one end to hang on to the edge of the container.

The etchings my students are able to get are amazing. Very clean and
can be very deep. We use PnP, vinyl, paint pens, stickers, paint,
fingernail polish, and stamps as resists. Some hold up better than
others, but we have gotten all to work.

I have attached the checklist I laminate and use at each station in
the classroom – just to make sure everything is is taken care of
properly! This might help with some of the issues some of you are
having with galvanic etching.

Deb

#15

Deb – where do you teach your classes?

Betsy