The metal surface has micro fissures, cracks, and porosities even after mechanical rust removal. The acid is supposed to neutralize the remaining rust you can't even see. Nasty stuff? Sure but it's in almost every soda. That's why you can use Coca Cola as rust remover.^
Phosphoric acid? That's some nasty stuff. What I do is remove the rust with abrasives, wipe down with acetone, and then primer.
Wrong acid. You're thinking of citric acid. Much more milder and friendly than phosphoric acid.The metal surface has micro fissures, cracks, and porosities even after mechanical rust removal. The acid is supposed to neutralize the remaining rust you can't even see. Nasty stuff? Sure but it's in almost every soda. That's why you can use Coca Cola as rust remover.
Wrong acid. You're thinking of citric acid. Much more milder and friendly than phosphoric acid.
If that makes you feel better it's fine by me."The two most common acids used in soft drinks are citric acid and phosphoric acid. Citric acid is found in citrus-flavored soft drinks like Sprite, Crush, and Mountain Dew. Phosphoric acid is found in darker sodas like colas and is the more harmful acid of the two."
Lakes Pediatric Dentistry
We're both right.