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What concentration and temp for Caustic Soda Etch

I am using caustic soda ⇦liquid caustic soda in bulk on Amazon [affil link] for my Aluminum Etch and need to know where I can find the concentration amount and the temperature range to operate my tank. At the moment, I am using 4 to 8 oz/gal at a temp range of 140 - 170 Degrees F. however, this was the setting that our old QM set. I need to know where I can find this information. GP17G and/or BAC 5786 do not provide information for Caustic Soda

Bob Pitts
Plating Quality Manager - Babylon, New York
February 1, 2008

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First of two simultaneous responses --

4 to 6 ounces per gallon is OK. 140 F is tops, do not go higher. At 170 F you cannot transfer to the rinse tank without streaking. You would be much better off buying a proprietary etch compound that contains chelators and sukrfactants.

Robert H Probert
Robert H Probert Technical Services

Garner, North Carolina

February 7, 2008

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Second of two simultaneous responses --

Bob

What works for us may not work for you. You have reasonable starting parameters. Adjust the parameters to achieve the results you are after, be it material removal or degree of appearance. Keep an eye on your aluminum content, though.

Willie Alexander
- Colorado Springs, Colorado
February 7, 2008