Also look for MacDirmid Iridite 14-2. It's basically the same product [Think Coke versus Pepsi] I would suggest trying to buy either one in powdered form. Vastly cheaper per liquid gallon when purchased that way. I bought a 10 pound container of Iridite 14-2 years ago. I sold the excess to other builders. Dorado Kote is another similar product.
My experience is that you get much, much better results if you dip the parts in the Alodine/Iridite, as opposed to trying to brush or sponge it on. This can be done quite safely with a little care. I've got photos of how I did this on my project and on a buddy's RV-9A project. Send me a PM with your email address if interested.
Link below shows some info on 10 pounds of the Iridite 14-2 powder. I can't remember off the top of my head where I got mine. I believe it was 1 or 2 states away from me.
For what it is worth, I’d like to suggest using the Sanchem system as an alternative to Alodine. The system is easily disposed of safely, it is water-based and nontoxic. I believe that many if not all European car manufacturers are using the system. I used it on my RV eight when I was building it in. https://www.sanchem.com/aluminum-pretreatment-conversion-coatings.html