The products I mentioned are used together such as PPG's SX579 and SX520.
When used properly are very effective at removing light surface rust but Are really meant to be used as a Metal treatment only and NOT a Rust remover, Heavy rust with pitting corrosion still needs to be removed by mechanical means such as sanding or media blasting.

The 579 cleans the metal and preps it for the 520, The 520 deposits a uniform layer of zinc phosphate on properly prepared steel surface perfect for Painting over and a added layer of Rust protection under Epoxy.

https://www.e-bodies.org/Resources/Mopa ... pec_36.pdf

https://ppgrefinish-na.uberflip.com/i/9 ... ide-2018/0?

chevman wrote:I'm not trying to discourage the use of phosphoric acid, users just need to learn all about it before using it. Its like most of the other products we use, learn to use it properly or you'll regret it.

You are 110% correct!
I went through a Lot of Duponts 5717 & 18 before I figured out how to use the stuff correctly, Theirs definitely a trick to using the stuff effectively.

If you don't use it properly it can and and will adversely effect Your paints adhesion!

Doright wrote:

chevman wrote:I'm not trying to discourage the use of phosphoric acid, users just need to learn all about it before using it. Its like most of the other products we use, learn to use it properly or you'll regret it.

You are 110% correct!
I went through a Lot of Duponts 5717 & 18 before I figured out how to use the stuff correctly, Theirs definitely a trick to using the stuff effectively.

If you don't use it properly it can and and will adversely effect Your paints adhesion!

True, my current understanding is the conditioner is a conversion coating, intended to give a better bond w/ the primer, much like alodine does to aluminum, nothing likes to stick to aluminum. apart from filiform....