The authoritative public forum
  for Metal Finishing since 1989
  

  -----

Etchant for Aluminium

Greetings all,

I have a group of H. S. students who need to etch al. plate to create a leather press plate. They have used ashphaltum stop-off but have found that it floats off in hydrochloric solution. What etchant should we use? Any advise would be appreciated muchly.

Dave Hunt
Pinehurst School - Auckland, NZ
2001

---

2001

There are a couple of letters on this site, including recent ones, that discuss the etching of aluminum both with acid and with alkaline solutions.

But I think your first problem is getting a better maskant, rather than trying to find an etchant that won't attack the maskant you are using. There are all kinds of good etch resists/stop offs, but for something instantly available, and perhaps good enough, you might try common electrician's black tape.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

The safest material that you can use is a saturated solution of bicarbonate of soda from your local grocery store. Use at a warm temperature. If this is not fast enough to suit you, add lye, one teaspoon at a time until you get the etch rate that you are looking for.

James Watts
- Navarre, Florida
2001