Instructables

Step 8: Etch

Picture of Etch
Use your favorite etchant--just make sure you give some thought to future disposal and consider a green process such as Peroxide/Cupric Chloride etching process (it is literally green, too). And, if you want to dig into the nitty-gritty details of the chemistry involved, this page is for you.
Hi. First off, your Instructable was very informative and useful; thanks for all the work that obviously went into producing it. I've been testing some of the same (or very similar, I believe) etch-resist film you have, with the idea of etching a brass plaque after exposing it through a pair of identical laser-printed transparencies (for better contrast). After two or three failed attempts, I found that throwing the whole thing in a zip-lock bag and zipping it shut on the nozzle of my shop-vac worked pretty nicely to keep everything tight together, and after seeing some sort of banding or striping in the exposure when I tried a fluorescent black-light tube about 10" above the target, I ended up just tossing it out the back door into the sunlight for about 10 minutes and that seemed to work pretty well. I may have to experiment more with exposure time, but it's starting to get pretty close.

The point where everything went to heck was when I tried using this technique to salt-water etch the developed brass plaque.  The resist film pretty much boiled off the surface of the brass after a few minutes, seeming to start around the exposed brass areas left after developing, and bubbling out from there.  So...  am I to conclude that this particular film is not suitable for salt-water electro-etching?  Is  there possibly a different kind that might be?  The article on electro-etching uses a CNC-cut vinyl decal as the etch resist, so I'm sure it's a lot thicker than the film I'm using.  Do you think that's the issue, or does the salt water break down this film?  If so, what's the least toxic etchant you might recommend that would work well with both brass and this film?  Any suggestions would be most appreciated.  Thanks!

-Bill
osgeld5 years ago
that link just goes to a blog page that changes constantly, how about changing it to link to the article
incoherent (author)  osgeld5 years ago
Thanks for the heads-up, I've got it fixed now. Regards, --incoherent