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Anodizing: Need Complete Procedure

 

Sir we are the manufacturers of aluminium canisters which are used for packing pharmaceutical but the problem is that when we anodize the canister for 40 mins then the colour of the canister turns to dark grey and when we do it for 15 mins then the spot comes we need 6 - 12 microns on the canisters and we want matte finish and bright silver colour could you please assist me which chemicals that we should use and at which percentage and at what temperature.

I would be very grateful to you if you please explain me the complete procedure from the scratch with all the details. Your prompt reply will be appreciated. Anxiously waiting for your reply.

Thanks/Best regards,

Gaurav Verma
- India

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Gaurav, the "complete procedure from scratch with all the details" fills hundreds of pages in such volumes as The Technology of Anodizing Aluminum [on AbeBooks, on Amazon, on eBay" (affil links)]. Which chapters of that book would you like us to omit in our response? :-)

Seriously, we can probably help with very specific questions, but only books can give you tutorial learning with all the details.

But the matte finish you desire probably comes more from an etching step after the cleaner and before desmutting, not from the anodizing conditions. Good luck!

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

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We are into the field of manufacturing all types of furnaces and silicon carbide heating elements. We have a plan to diversify into other business. As we are not having much experience in the field of anodizing, could you please help us in detail?

Nagaraj G
- Bangalore, Karnataka, India
2002

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Please start by telling us in detail how to make furnaces and silicon carbide heating elements :-) There is more or less the same amount of detail involved in how to do anodizing :-)

Actually, start with some books about anodizing.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2002

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I am a student and I want to know what materials, etc. are needed for anodizing aluminium in a science lab.

Guy Davis
- Aylesbury, Bucks, England
2003

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A suitable type of aluminium (say 99.5% pure, or another suitable alloy) as your anode, lead sheet as the cathode, 10% sulfuric acid, a rectifier capable of delivering up to 100A/ft2 and a lot of ice to keep the electrolyte cold Trevor Crichton R&D practical scientist Chesham, Bucks, UK 2003 That would totally depend on what kind of anodizing of what material you want to do. A trip to the Library is a wonderful place to start. James Watts - Navarre, Florida 2003

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Your post did say aluminum. But, is this to be chromic or sulfuric or phosphoric anodizing? A trip to the library would still help. In sulfuric acid anodizing. Aluminum will work as well as the lead for the cathode. Your power source should go to at least 15 volts at full load. The 10% is by volume if you are using lab grade sulfuric. About 1:1 if you are using battery acid [affil links]. Caution, acid to water, not vice versa and it generates a huge amount of heat. The ice is in an outer double boiler, not in the acid. 72± 2 °F for decent product, mild agitation. Seal in boiling DI water.

James Watts
- Navarre, Florida
2003