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  for Metal Finishing since 1989
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Acid Types in Autophoretic Process

In the Autophoretic process, a "mild acid" is used to etch the surfaces to be coated? Does anyone know what type of acid is commonly used and in what dilution?

Kevin Arcoraci
- Columbus, Indiana

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Hey Kevin,

Are you using this material in your process lines?

If so, then write this down:

M S D S

Now, take this to the management and let them know that you know what this means and you need answers. NOW!

Tom Baker
wastewater treatment specialist - Warminster, Pennsylvania

WELL SAID TOM

John Tuohy
- Ireland

We do not use an autophoretic process at our facility, however, we supply rubber parts to customers that have to "endure" this process. I just wanted to make sure that our compounds were compatible with the fluids involved with the autophoretic process.

Kevin Arcoraci [returning]
- Columbus, Indiana, USA

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Hi, Kevin. It's hard to say exactly what steps proceed the autophoretic process, but probably phosphatizing which uses phosphoric acid -- indeed a fairly mild mineral acid. Rubbers, PVCs and polyolefins are probably resistant.

Sorry for the earlier misdirected responses, but at least this way the readers can see an example of why we ask that folks post their 'real world situation' rather than 'abstract questions' :-)

Good luck.

Regards,

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

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Hi Kevin

The acid used inside the Autophoretic bath is HF with fluoride activity = 250-300 mA

On the other hand, some autophoretic processes use acid pickling (HCl,H2SO4 ,..)

July 10, 2011