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Stripping EN from aluminum

I am trying to strip EN, mid-phos off of 6061-T3 aluminum. I tried a ammonia [on eBay or Amazon] base stripper that I bought, but it does not seem to be working. Can I use sulfuric acid anodically with a lead cathode to strip this part or can conc. nitric acid still work without harming the aluminum substrate ?

Mark Batich
plater - Atlanta, Georgia
2004

You can strip EN in red fuming nitric acid. Possibly with a slightly weaker strength, but that is a risk! The part has to be absolutely dry or you can kiss that portion of the surface goodbye.

James Watts
- Navarre, Florida
2004

Try stripping with nitric 50%. Don't live parts for long time after the plate strip.

Gabriel Schonwald
Bnei Berak, Israel
2004

The amount of water you can stand depends on the surface finish you need. My experience was on a burnished surface with extremely tight dimensional tolerances. Could not stand any water. Also, it will depend on the alloy. Virtually any mixture of nitric will work on 1xxx series aluminum. 7075 or 24xx aluminums have a high % of alloy material that will etch. So, IT DEPENDS!

James Watts
- Navarre, Florida
2004

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First of two simultaneous responses --

I tried conc. Nitric acid, with a dry and clean part. It worked great! I did not have any etching, but it did take about 1 hour to remove the coating.

Thanks,

Mark Batich
plater - Atlanta, Georgia
2004

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Second of two simultaneous responses --

You can strip Ni layer off by 2 methods are use electrical(sulfuric solution) or by chemical (50 % dilute nitric acid) last method is easier the first, but the first suitable for Al alloy.

Tawatchai Sujitranuruk
- Thailand
2004

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GREETINGS MR. BATICH,

IM VERY HAPPY TO SEE YOU ARE DOING WELL WITH YOUR DEGREE IN CHEMISTRY. I WISH YOU CONTINUING success.

J. CRAFT
- KNOXVILLE, TENNESSEE
2004