"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
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.