I decided to add some acid to my ultrasonic cleaner. "Concrete prep," it's dilute phosphoric acid. I used much less than the normal concentration. I'll report back on the results. Hopefully I can get it neutralized okay. They recommend painting within 48 hours, but that's not going to happen.
I'm pretty sure the recommendation for pickling is because they are addressing industrial users. Back in the steel days, Trek had an elaborate chemical setup which had a very dilute acid to remove flux, just like Harris recommends. It worked great. I'm reasonably sure it was phosphate based.
The electrician fell into that tank and thought he was going to dissolve. Well, his clothes were not going to survive a washing, but he was fine. That's the only time I ever used one of those chemical showers. The tank was heated and had a fairly thin plastic cover which wasn't strong enough to support a person's weight. The electrician thought it would support his weight.
Last edited by unterhausen; 05-03-19 at 09:21 AM.