alodine expiration?

I just purchased my second gallon of alodine and noticed that the new (to me) alodine changes the aluminum color much faster than the year-old stuff does now. This got me to thinking about the expiration of alodine... is there one? And what causes the alodine to not, uh, do the allodine thing as effeciently? Is it sunlight? Air? Cold? Heat? Time? Thanks for your time. -Jim, 40603

keywords: allodine, alodine, expire, alidine, aladine, 1201, primer, prime,

Sunlight is a big one. Put it out in the sun and it seems to go bad pretty quickly.

Personally, I bought a couple of pounds of the powder and mix my own. When you buy the pre-mixed gallons, you're paying a lot of money, including shipping, for water.

PJ Seipel
RV-10 #40032