I saw an article that says to not let Alodine sit for more than four
hours after application. One question is, does the group agree with
that? Second, if you don't get primer painted by that time, do you try
to wash it off, reapply, what?


The proper application of alodine is after application and set up time to wash
off the excess with clean water. You are not supposed to simply apply it and
let it dry. Alodine is a chemical conversion process and not a coating.
Having applied the alodine and washed off the excess after the appropriate time
nothing need be done until priming. The part can be stored indefinitely. I
have been told that leaving alodine to dry on the part will promote corrosion
eventually but have not seen this in literature.

I was taught that alodine will leave an almost microscopic film or sheen on the
metal that if the metal changes color to a deep gold or brown than it was left
on too long. I was also taught that zinc chromate primer was supposed to be
applied so thin that you could read newsprint through it or read the printed
labeling on the sheet metal. I have rarely seen zinc chromate applied so.

John Dupre'