Copper Etching Discussion

[Laura B]

Originally Posted by houptdavid

Kim Thank you

It is the "you can flush it away" part. While yes IN some places you can still do this, in others you cannot and need to be informed of this even in trace quantities.

Excellent point, and each consumer should make it their business to find out what can and cannot be disposed of in their own county.

While I personally like the idea of using a less toxic substance for my etching than most of the current offerings, if/when the time comes to dispose of any substance I will do what I always do which is go to the web page of my local waste disposal depot and find out what is permissible in my county.

[tgslampwork]

Fair enough - but it should not be lost on folks that SF is (was?) also looking into making circumcisions illegal and it seems everything causes cancer in California Must follow local ordinances and laws, but I'm hardly ready to use SF's laws as a guideline as to the dangers of the solution in the concentration for etching.

And I'm a flaming liberal.

[tgslampwork]

Oh, and David - this thread really is a great service to the community! Having everything in one place is a dream. I can't tell you how many times I've googled looking for various articles and such. Thanks a ton!

[houptdavid]

It took me a while to find this to answer a question about the Salt solution and Rectifier/battery

From thenakedscientists.com:

When you pass an electric current through a solution, ions (charged particles) migrate towards the electrode of the opposite charge.

In a salt solution (NaCl) the dominant species of ions are sodium (Na+) and chloride (Cl-), because only a tiny amount of water (H2O) is ionised (to H+ and OH-) at pH 7, and that's why pure water is very difficult to electrolyse (and why teachers add acid to help the process).

So when you apply a current to the solution using copper electrodes, the chloride ions (Cl-), termed anions, will move towards the positive electrode (the anode), whilst the positively-charged sodium ions (the cations) will migrate towards the negative electrode (the cathode). The migrating ions carry charge through the solution and hence help to complete the circuit.

At the anode 2 chloride ions (Cl-) will each surrender an electron to the anode (which likes electrons because it is positively charged) to form a molecule of chlorine gas, which you see fizzing off :

2Cl-(aq) -> Cl2(g) + 2e-

At the same time, the copper (Cu) forming the electrode will also try to donate electrons :

Cu(s) -> 2e- + Cu2+(aq). When the copper (Cu) gives up 2 electrons it forms a copper ion (Cu2+) which then goes into solution, turning the electrolyte blue / green, as you have observed.

At the negative electode (cathode) hydrogen ions (H+) from water pick up electrons to form hydrogen :

2H+(aq) + 2e- -> H2(g)

...and the copper ions (Cu2+) which were mobilised from the anode also pick up electrons to form metallic copper which is deposited on the cathode :

Cu2+(aq) + 2e- -> Cu(s).

So the slight amount of sludge you end up with is copper chloride. During the electrolysis process, you bubbled off hydrogen and chlorine gas. Copper chloride is none too friendly, either.
************************************************** ***********************************
Copper chloride= cupric chloride CuCl2

[Barrie]

You totally ROCK David! Thank you for putting this together - wonder how we go about making it a sticky???? I want to add to the resist list - nail polish is fantastic (you can thin it down to a great consistency for painting fine lines), and Testors enamel paint is another great one.

[houptdavid]

Barrie Thanks I added it to the list. I have know idea?

[Venessa]

I've used StazOn ink and stamps as a resist with the muriatic acid/hydrogen peroxide method, and it worked well-although I would have preferred a deeper etch. I am going to try the salt solution with a battery charger-hopefully today. I tried yesterday, and discovered that the 'copper' wire I was given was just a copper colored aluminum...thought it felt a bit soft when I cut it

[houptdavid]

Venessa
The cupric chloride (peroxide/HCL) solution needs a fish tank bubbler to work and about at least 2-3 hrs in the tank.

[Beadbug]

I have used the following with great results.

Rectifier and salt solution

Muratic acid / Hydrogen proxide

Resists
scotch tape, sharpie markers, Stayz on ink

[Venessa]

here is a link to what I did with the acid/peroxide-I like the initial results, but really want to play further and see what else I can do. also-wore this one to work the other day and people were asking how much-any ideas? I'm horrible at pricing!


ETA: guess it helps if I put the link...
http://www.facebook.com/album.php?ai...9&l=a6f0fac1b1

[Kevin Marshall]

In pure etching, a metal plate is covered with a waxy country, which is resistant to scratches then acid.The artist started with a sharp needle etching where he wants to coach is willing to work in order to expose the bare metal. Échoppe, instrument tilted oval section is also used for "swelling" lines.The plate immersed in an acid bath, technically called the mordant (bite) or etchant, or acid washed over it.The acid "bites" the metal where it is exposed, leaving behind lines sunk into the pot. The rest of the country is then removed from the plate. The disc is inked all over, and then the ink wiped off the surface, leaving only the ink lines engraved.

[Holaday]

Thank you for the excellent list and links. I found lots of great things related to patinas when I followed the link you provided.

I use PnP because I like the photography part of the option. I have excellent results using a pancake griddle set at 350 and a folded soft paper towel to burnish the PnP to the hot metal.

I used ferric chloride for years but don't like the stains and the ammonia required to neutralize it. Recently had a workshop with Carol Webb where she demonstrated sodium persulfate for etching copper. Much cleaner and easier to clean-up. http://www.opencircuits.com/Chemical_Etchants

I was very pleased with my 16 gauge nickel plates that I have since used to roller print copper. Etch was slow, but clean. Could speed it up with more heat and a bubbler I think.

A few of my students explored the battery/salt water option and were pleased with results. Together we are going to explore a variety of methods to hopefully find the best/least toxic/most affordable option. Legal disposal of the dissolved copper is an issue, so now we are looking into plating the copper onto something.

Carol Webb demonstrated the use of a citrus based heavy duty cleaner that worked very well to remove the PnP. No more acetone!

[animagusbc]

This might sound like a retarded question but where do you buy PnP Paper from? Any Suggestions? Sorry, Newbie Question

[Ari'elle]

Oy! Deja vu...

Originally Posted by animagusbc

This might sound like a retarded question but where do you buy PnP Paper from? Any Suggestions? Sorry, Newbie Question

[Ari'elle]

Here's some on ebay:
http://cgi.ebay.com/ws/eBayISAPI.dll...=STRK:MEWAX:IT

[houptdavid]

Originally Posted by Ari'elle

Oy! Deja vu...

[animagusbc]

Thanks for all the information. Just went out to my supply house and bought the etching solutions for Copper and Silver. PNP paper is coming and should be soon as it's in my neck of the woods. Can't wait to work on a piece now.

[houptdavid]

Heres another on using a laser printer/toner copier and photo paper
http://fullnet.com/~tomg/gooteepc.htm (added to the list)

[menty666]

I created a salt solution

Cut a small piece of copper, and wrote something on there with black sharpie to try to act as a resist.

With my battery charger I hooked the negative to a piece of copper wire, the positive lead to the copper to etch and put that into the solution, switched it on, and nothing.

I broke out the jumper cables, hooked negative to the copper wire, submerged that.
Hooked to the marine battery, hooked positive to the copper I wanted to etch, submerged that and it bubbled for a bit, turned an unhealthy looking yellow color, but other than some obvious discoloration, it didn't etch, per se. It's very likely I didn't leave it in there long enough. I used rubbing alcohol to remove the rest of the sharpie instead of acetone, but it didn't seem like the surface was raised at all from the surrounding copper.

Some questions...

Do I just need to let it bubble for longer? I didn't coat the back of the copper I was trying to etch, so I was very cautious not wanting to eat it all way.

What is the solution that's in the jar now? I'll likely need to know when it comes time to take it to hazardous disposal.

I dropped the rest of the negative copper wire into the solution. Not sure if I had created an acid or not, I didn't go digging around in there to find it, but do you have any suggestions for getting it back out? I could probably make some tweezers out of some copper wire if need be.

[papimom]

You need to leave the plate in longer. The solution definitely turns a hideous mungy pumpkin orange. Instead of Sharpies, I use Da-cor Permanent Color Pens as my resist.
Plate needs to be super clean to start. Pen design needs to dry completely.
Keep going, you are on the right track.
Joan

[menty666]

Thanks! I was actually just coming back in to give an update...it definitely did etch a tiny little bit, I can see now that it's dry.

So, definitely a good first attempt

Can I reuse the solution I have down there one more time or do I need a new one? It should still be super conductive, but if copper sloughed off into the mess that could be disruptive.

[Venessa]

You can use the solution repeatedly. I've not thrown any out yet, just add a bit more salt water when necessary. I had no luck when I used a battery charger, so I bought a lawnmower battery at WalMart for $20, and it works great! And, when it stops working, I just recharge it with the battery charger

[Laura B]

Originally Posted by papimom

You need to leave the plate in longer. The solution definitely turns a hideous mungy pumpkin orange. Instead of Sharpies, I use Da-cor Permanent Color Pens as my resist.
Plate needs to be super clean to start. Pen design needs to dry completely.Keep going, you are on the right track.
Joan

For these two steps I use: rubbling alchohol to remove any finger oil and a hair dryer to heat-set the resist ink.

[menty666]

Thanks folks I had cleaned the plates with alcohol prior, but my oldest minion may have touched the plate while I wasn't looking.

I'll give it another goo this weekend. Oh, and I'm glad to get some use from my marine battery in the off season.

Oh, btw...what do folks do to attach the lead to the plate to be etched? Just include a little extra as waste? I didn't want to actually dip my jumper cable lead since it's copper too

[Venessa]

Yep, I just use some copper wire to attach the plate to the battery.

[beadaddicts]

I'm using the ferric chloride method to do my etching, but as far as cleaning your metal before adding your resist, ditch the alcohol, and give it a few good scrubs with some 0000 steel wool instead. Works like a charm!!

[houptdavid]

Tom use a strip of scrap copper connected with packing tape to the back, also make your cathode the same size as what you are etching if you are using a plastic tank.

[Laura B]

Originally Posted by beadaddicts

I'm using the ferric chloride method to do my etching, but as far as cleaning your metal before adding your resist, ditch the alcohol, and give it a few good scrubs with some 0000 steel wool instead. Works like a charm!!

Interesting. I've had great results with my current method (600 grit sandpaper then alcohol).

I may experiment with steel wool rather than alcohol just to see if I find a difference.

Thanks for the tip.

[Laura B]

Originally Posted by menty666

...
Oh, btw...what do folks do to attach the lead to the plate to be etched? Just include a little extra as waste? I didn't want to actually dip my jumper cable lead since it's copper too

I tape an aluminum wire onto the back of my piece to be etched.

[Lizzydee]

thanks for all the helpful info!