Coating aluminum

..Blueskies. wrote:
"Lou" wrote in message oups.com...

So, let me get this right,
acid bad
Alodine good.



Alodine is acid - chromic acid.



I hear the confusion, Lou. Yes, alodine is also acid, but what your
doing is using the acid in a CONTROLLED environment. You put the piece
in the alodine bath for only a short time. Leaving it there for
extended periods IS bad. It'll eat your part up.

After you get the surface coated with a good layer of whatever chromium
compound it is that the alodine leaves behind, you pull it out of the
solution and wash it with clean water. As soon as it is good and dry,
you put a coat of primer on it.

The post about bases is spot on, except that you don't find them in the
air much. Most of the acid in the rain is put there either by burning
coal or diesel fuel. As Morgans pointed out, the air around diesel
driven air carriers has given the Navy fits for decades.

--
This is by far the hardest lesson about freedom. It goes against
instinct, and morality, to just sit back and watch people make
mistakes. We want to help them, which means control them and their
decisions, but in doing so we actually hurt them (and ourselves)."