ink for resist

Ok, sort of strange request.

I have been doing some drawings for school...art classes. I draw them on copper sheet with a sharpie, or other perm marker. I then use ferric chloride to etch the copper. Treat the whole thing with liver of sulfer to blacken it, then remove the sharpie with acetone. Leaves a nice bright shiny copper with a black background. Really a neat effect.

I would like to find an ink that I can brush on, so I can do work that is more of a "Japanese brushwork" style (if anybody knows what that is. THe problem is, I can't seem to find an ink that will adhere to the copper, but is still fluid enough to brush. (want an ink that has a low viscosity).

I have tried most available art and drafting inks. The only solvent based liquid ink that i can think of is dykem, but it's more of a dye. I have to get a bottle to see if it resists the ferric chloride.

Any other thoughts or ideas?

-jacob

Some years ago, I had to etch some printed circuit board material and I used a resist purchased at Radio Shack. You might try that.

Also, as I recall, a coating called asphaltum (or something like that) is used as a resist for zinc plates used in intaglio printing which can be thinned. (I dated an art major when I was in college.)

On the below site are few ideas for working with resist.

http://www.artelino.com/articles/intaglio_printmaking.asp

Use a fine hair brush that will give the characters you want. For paint use plain old acrylic artist paints, thinned as needed. Then, bake it in the oven at about 200 degrees. Etch, and then clean with methylene chloride stripper.

might try nitrocellulose, thinned in acetone or
mek. most nail polish is nitro that i'm aware of,
as is good old fashioned lacquer paint. i've
used thinned nail polish to mask pc board traces
in
Fe chloride , and it worked extremely well , and
wiped right off with mek.
i don't think acrylic paint would do as well
on the bare copper, being water based/thinned .
good luck.

Have not tried acrylic paint, but I have used several types of varnish with good results. I don't know how far you could thin it for brushability before it got too thin to work.

The asphaltum type materials are more often used as an overall coating which you then scrape off where you want to etch. Kind of like the old multi-layer crayon pictures when you were in 1st grade. I don't know how controllable they are if you want to paint them on as the pattern, I never have tried that.

nail polish?

Have you tried india ink? That's traditionaly the ink used for Japanese sumi paintings.

I've never tried this technique for etching copper, but it sounds really interesting. Just wondering, where do you get ferric chloride from?

Andrew

I've tried asphaltum when chemical machining HSS in ferric chloride. I was using a dc supply to etch the HSS away. The asphaltum seemed to have an ongoing problem with pinholes as I kept getting spots where the HSS would etch despite being coated with asphaltum. The resist pen from Radio Shack works, but not 100%.

The spray coating photoresist seems to do OK and I have had some luck with laquer (nitrocellulose). The key seems to be that the resist must be waterproof and free of pores.

I get ferric chloride by the gallon from my local electronics supply store.

-Jacob

Perhaps your problem could be solved by giving the copper surface a bit more "tooth" before applying the inks. You might try some 320 or even 600 grit paper to rough it up a bit. Clean with alcohol to remove any oils and them try brushing the inks on.

You can polish or whatever to get the appearance you want after etching. You have to clean the ink off anyway.

Paul A.

I'll second the "tooth" factor. I used to make many pcbs with sharpie on copper and found that for "bulletproof" adhesion, scrub the copper with a cleanser like Comet and a tootbrush in a circular fasion. More modern abrasive cleaners with oxalic acid seem to do the job even better, no doubt due to some slight etching effects. Den