Lye as an aluminum cleaner?

In article ,
Orval Fairbairn wrote:

In article ,
Michael Horowitz wrote:

I've taken my aileron apart and notice corrosion on the thin aluminum
parts, so I'm reading around about cleaning prior to alodining. I've
taken a stainless steel brush to the surface and removed most of the
corrosion, but it's really a PITA.

Someone suggested using lye as a cleaner. Anyone have any experience
using supermarket lye in that role? - Mike

Yes -- lye is used as an etch prior to alodyning. I would, however, use
a mild phosphoric acid solution first to remove the corrosion.

The aluminum should be left in the lye solution (NOT Drano, as it
contains potassium hydroxide, in addition to the sodium hydroxide) for
no more than 5 minutes -- just enough to etch the aluminum.

The handbooks recommend a sodium hydroxide solution heated to 120 F for
best results.

Sorry -- I neglected to state that you have to rinse the metal
thoroughly after the lye etch, and before the alodine.

"Orval Fairbairn" wrote in message
news
In article ,
Orval Fairbairn wrote:

In article ,
Michael Horowitz wrote:

...
Yes -- lye is used as an etch prior to alodyning. I would, however, use
a mild phosphoric acid solution first to remove the corrosion.

The aluminum should be left in the lye solution (NOT Drano, as it
contains potassium hydroxide, in addition to the sodium hydroxide) for
no more than 5 minutes -- just enough to etch the aluminum.

The handbooks recommend a sodium hydroxide solution heated to 120 F for
best results.

Sorry -- I neglected to state that you have to rinse the metal
thoroughly after the lye etch, and before the alodine.

Well, I guess you learn something every day.

--
Geoff
The Sea Hawk at Wow Way d0t Com
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You can say that again. I printed that text out for my keeper file.
Excellent information. Thank you.

Don...