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How to etch copper tubing


I’m wanting to etch copper tubing for jewelry without the etchant going inside the tube and weakening/ thinning the tube. Can anyone explain how to do this, please? I’m assuming drill holes at one end and hang in the ferric chloride solution. But can I use silicone one the end in the liquid? If so, what kind of silicone can go in ferric chloride?

Thank you, Brenda Muntz

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My info is from book learning not experience, so take it with a grain of salt…can you coat the inside with your resist?


tape the ends – like a drum skin.


I’m thinking you could plug the ends of the tubing, maybe with wax or something like it.

Janet Kofoed


What if you just soldered the ends closed, with a soldered L and a loop at each end. After etching, just cut the ends off.

Yes, you can solder something close without a relief hole, just don’t heat it twice.

Karen Christians
Western Avenue Studios #506
Lowell, MA 01851
781 367 4992


For copper you could do a salt-water & electricity etch. Your cathode would wrap around the tube without touching. I have a PDF book written on the subject. I still need more photos before I can publish.


Yeah, but it would etch the inside too. You still need to protect



I would think you can use any type of silicone, if that’s what you really want to use. I think you’d be fine with just some tape actually. Tape the end off and just make sure you cover the tape with the resist and you should be fine. And I agree with beadbryant, use the right resist and you shouldnt have an issue just coating the inside.

You could drill a hole at one end, or maybe tightly wrap it if you want to avoid the holes.


Actually, tape will not work well unless it’s got a really strong
adhesive. I’ve used masking and other tapes as a resist and the
etchant gets underneath it because the adhesive loosens due to the



I never tried with tape, but I figured if it was covered well with the resist, it would be fine. I’ve done a fair amount of ferric chloride etching, but always use the same hard acrylic resist.


What is the diameter of the tubing? Can you seal the ends with PVC caps and PVC adhesive, or even copper caps? It wouldn’t have to be a solid, rather permanent seal as long as it kept the liquid out of the tubing. I do etching from time to time. You might even try a plastic Saran-like wrap and rubber bands.
Dick Stromberg Ah Mexico! Where “C” on a faucet means HOT, and “M” on a restroom means THE LADIES ROOM.


If you simply plug the ends, either with tape or a resist, the tubing will want to float because of the air trapped inside.
Whether you’re creating the image to be etched using one of the heat set films or old fashioned asphaltum and a scribe, the thing to do is to dunk the tubing into a thin, paint on resist so that it is coated on the inside, leaving the ends open.
Then you can either scribe through by hand on the outside or remove the resist on the outside so you can use a heat setting resist film.
The resist on the interior will come off afterwards with a bath of appropriate solvent.


If I understand correctly- or at least in my experience, the salt water & electricity etching is line of sight .
In other words the inside of the tubing could not be etched & the salt water alone is not enough of a chemical to harm it.

On a side note to FSGmetal - I’d love to see your PDF book. I’m always looking to learn something new and learn new tips on etching.
Live Oak Studios


Salt-water & electricity etching is NOT line of sight. It will
etch the inside of the tube if you do not protect it. I’ve been
doing this kind of etching for years now and have seen this happen.

As you can see in this picture:

The back (except for the square where my logo is) was protected with
tape and it still etched a little.  This is what I was talking about
previously w.r.t. tape not being a good resist.  And this shows that
electrolytic etching will etch ALL SIDES of a piece if it is not

I have a somewhat outdated tutorial here on this process:

It's outdated because I no longer use toner transfer for my resist,
because I kept getting too many pits.  I now use UV film.



I just remembered something that is probably resistant to ferric chloride, if indeed this is what you are using.


This is a wonder material that replaces jet set for many of my fabrication processes, like a handle for setting stones.

Karen Christians
Western Avenue Studios #506
Lowell, MA 01851
781 367 4992


I do have thermo loc I can use. I agree tape is not secure. Unless electric tape? Would a cork stand up to FC?


Epoxy is supposed to stand up to chemicals. Tape on paper and cover with epoxy or resin?


I have successfully etched copper tubing. I cover the opening with contact paper, cut larger than the holes. Then, fasten it securely with mailing tape, going around the paper several times to make it secure. Then, in addition, put more tape over the contact paper. This has worked for me. Alma


Wax works fine, in my experience. If floating is a problem (seems unlikely
to me) fill the tube with sand before sealing the ends by jabbing them into
sticky wax.



I had to do a little research before I could reply Mike- as that hasn’t been my experience.

From what I read yesterday , you’re absolutely right , electro etching in salt water is not " line of sight" in some instances - basically it can depend on the size of the container you are etching in.

Looking at your page, you use a 5 gallon bucket , where I use a small plastic storage container.
In the 5 gallon bucket, if I understand correctly, it allows the voltage to create a large “field” to surround your entire part. Where in my small plastic container , there
is not enough space around your part to allow a large field of voltage to develop.
Hence our varying results.

Learn something new everyday !
Guess I’ll have to try it out.

Live Oak Studios