-- The Home Page of the Finishing Industry
Serious Education & the most FUN
you can have in metal finishing smiley

No popups, spam, registration or passwords
on this site
current topics
topic 10102

Can we do Iriditing of Aluminum in house?


Q. We have over 40,000 aluminum parts 2" diam. by 2" lg that will need to be Iridited. Is Iriditing something we can do if we buy the necessary chemicals? What are the short comings to doing this job ourselves? The prices we have got for Iriditing seem high to us. Can you give us any advice?

Fred Pfirrmann
- Glendale, Ohio


Iridite is a Macdermid trade name for a line of processes for Mil-DTL-5541 chromate conversion coating ("chem-filming") of aluminum. Alodine is a Henkel trade name for the same.

As the responders note, the biggest challenge to doing it in house is that chromating of aluminum, like electroplating, is an EPA "categorically regulated" process.


A. You probably do not want to do this in house.

Iridite has chrome in it and thus is hazardous waste.

Also, you would need many more tanks than just the Iridite. You would need pretreat cleaning & rinse tanks.

David A. Kraft
- Long Island City, New York


A. Doing an adequate job is not difficult if you follow the instructions. Waste treatment is the problem. There is considerable expense and a lot of paperwork that goes with it, not to mention having to go to school regularly for haz waste handling and shipment of haz materials (about $2000).

While not closed loop, it can be contained and treated, and shipped off twice a year, negating the expense of testing every time you go to sewer.

To do this, spend the money up front and put 4 rinse tanks back of each process tank and counter flow them with a bucket.

Initial cleaner requires heat, quite a bit. Costs more initially, but heater lasts a lot longer if you go with a derated heater. A double derated is better, but might not be worth the extra cost as well as it takes up twice as much space.

Iridite tank will require a tiny amount of heat in the winter. Final rinse tank will work better with a small amount of heat.

Big cost--hoods and exhaust system--Probably a scrubber in some locations.

15 years ago there were 20 to 30 shops around here that did Iridite type process. Now there are 4. That says a lot.

James Watts
- Navarre, Florida

"Surface Treatment & Finishing of Aluminium and Its Alloys"
by Wernick, Pinner & Sheasby

from Abe Books
info on Amazon


A. The training and waste treatment requirements of the Iridite process usually make it not cost-effective to do it yourself. One way to cut down on the cost of having a job shop do the coating is to have it processed in bulk rather than on a rack. This lowers the cost dramatically and provides an almost identical quality level. We specialize in such bulk processing, please contact us at

Jim Gorsich
Accurate Anodizing Inc.
supporting advertiser
Compton, California, USA
accurate anodizing banner

If you have a question in mind which seems off topic, please Search the Site

ADD a Comment to THIS thread START a NEW threadView CURRENT TOPICS

Disclaimer: It's not possible to 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 may be deliberately harmful.

  If you need a product/service, please check these Directories:

JobshopsCapital Equip. & Install'nChemicals & Consumables Consult'g, Train'g, SoftwareEnvironmental ComplianceTesting Svcs. & Devices

©1995-2018, Inc., Pine Beach, NJ   -   About   -  Privacy Policy
How Google uses data when you visit this site.