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Iridite is smutty

I am using 25% by volume nitric acid as deox (I've even tried 50%) I still have to wipe the traces of smut off the aluminum parts in order to get smut free clear Iridite finish.

Adel Taghdi
Nepean, Ont.
1999

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First of two simultaneous responses--

1999

Hi Adel ,

i suggest that you try the following Deox it is in wide use on Al / alloy wheels as a Deox
30 % by volume of 70% Nitric Acid
20 % By Volume of 98% Sulfuric Acid
1 pound to the US gallon of Ammonium Bifluoride

Be careful with it but it definitely works especially on alloys with high copper & high silicon .

Best regards

John Tenison - Woods
- Victoria Australia

 

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Second of two simultaneous responses--

You didn't specify the alloy you are trying to chromate. There are several types of deoxidizers for the various types of Aluminum so you have to match the chemical to the alloy.

Jim Conner
Anoplex Software

Mabank, Texas USA

1999

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Hi

If the aluminum alloy is high in copper or silicon you could try Deoxidiser 7-17 which I have found to be most successful either as a deoxidiser or a desmut.

I am replying from the UK but there must be an equivalent material in the US.

Brian James Ormsby
- Southend on Sea
2005