I'll say it again, if you use any acid product to neutralize the rust you need to keep it wet and then rinse with water. Never let it dry, you will then have an acid film that will severely affect adhesion especially if you are applying epoxy over top. If it does dry simply wet it again with the product and rinse with water. Improper use of acid etch products is one of the biggest causes of paint failure with modern paint systems.
If you abrasive blast then epoxy you don't have to worry about using any sort of acid etch. With epoxy there is
zero need for it after blasting.
Check out this video demonstrating the adhesion of SPI (Southern Polyurethanes) Epoxy primer. And the lack of adhesion after improper treatment with an acid etch(Ospho).
https://www.youtube.com/watch?v=-yA8q4K-_Bo
Any questions about acid you can go to the SPI forum and speak directly with the President of the Company Barry Kives. He is an expert on this and all things paint related. SPI's Tech line is his Cell Phone. He personally answers any questions someone may have regarding use of a product. Super guy and the best epoxy primer on the market.
Called him once on a Sunday afternoon, I was stuck in the shop trying to finish a Corvette all over job. I had a question so I dialed him up. It rang 4 or 5 times I decided that I didn't want to bother him on a Sunday, as I knew the answer to my question just wanted a second opinion. So I hung up. 5 minutes later he
calls me back! At that point he didn't know me either. After that I was sold on the customer service provided by Mr. Kives and his employees and the superior products he offers. Case in point
Best of Show Pebble Beach 2015 an 1924 Isotta Fraschini was an all SPI car. Epoxy, Basecoat, and Clear, all SPI products.