-----

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
(Ted can offer longterm or instant help)
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

---