No registration or passwords; no pop-up ads -- just aloha, fun, & answers.
(as an eBay Partner & Amazon Affiliate earns from qualifying purchases).
Home /
T.O.C.
Fun
FAQs
Good
Books
Ref.
Libr.
Advertise
 
Help
Wanted
Current
Q&A's
Site 🔍
Search
pub  Where the
world gathers for metal finishing
Q&As since 1989



-----

Recommended Chemicals For Aluminum Etch




April 21, 2011

Hi,

Currently I'm in the midst of my evaluation to etch aluminum. Fyi, I'm trying to etch a layer of aluminum deposits from aluminum base. Have tried with KOH, Nitric acid and phosphoric acid. Etch rate with KOH is too fast, that it etches the base material too much.
But, Nitric acid and phosphoric acid etch slowly and etch both aluminum deposition and aluminum substrate at almost the same rate.
What would you recommend to etch the aluminum deposits faster than the etching of aluminum substrate. Or at least to soften the aluminum deposition so I can easily remove it by abrasive blasting afterwards.

Peter Doherty
Engineer - Malaysia



Hi, Peter.

How were these aluminum deposits deposited? Were they deposited in such a way that the deposited aluminum is chemically different than the aluminum of the substrate? If the deposited aluminum is fundamentally different, like an aluminum oxide, you might try the chromic acid / phosphoric acid mix that is used to strip anodizing. It is described in letter 2776 . Good luck.

Regards,

Ted Mooney, finishing.com
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
April , 2011



April 26, 2011

Well,
If you are attempting to remove aluminium oxide the normal solution would be to employ a Hydrofluoric acid etch.
This is very nasty, dangerous stuff.
Your Enquiry is somewhat unspecific so maybe a further elaboration would help us to help you.
If you are not adequately qualified do not even try playing with Hydrofluoric.
Hope this helps,
Regards,
Bill

William Doherty
Trainer - Salamander Bay, Australia



April 26, 2011

Peter

If you are trying to remove flame spray / TWAS aluminum off aluminum, removing most of the deposit with blast prior to the chemical strip might be more effective.

I second the HF advisory.

Willie Alexander
- Colorado Springs, Colorado




(No "dead threads" here! If this page isn't currently on the Hotline your Q, A, or Comment will restore it)

Q, A, or Comment on THIS thread -or- Start a NEW Thread

Disclaimer: It's not possible to fully diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations might be harmful.

If you are seeking a product or service related to metal finishing, please check these Directories:

 
Jobshops
Capital
Equipment
Chemicals &
Consumables
Consult'g, Train'g
& Software


About/Contact  -  Privacy Policy  -  ©1995-2024 finishing.com, Pine Beach, New Jersey, USA  -  about "affil links"