Phosphoric acid is also a main ingredient in Naval Jelly. This is also available at hardware stores and has the advantage of being viscous, like jelly. So, you can put it on and it stays put, like the studs pointing up on the horizontal wheel.
True. Naval Jelly does work well for removing rust and preventing rust.
There are a couple reasons why I did not use it.
First, it is very slow acting compared to the liquid solution. This is because the phosphoric acid is not "mobile" in the suspension. I would have taken weeks to do the same action on these bolts.
Second, I was in the position of having to treat these wheels out of doors in the sun/rain/come-what-may. Naval jelly will melt and run when exposed to heat or sun. Rain would have washed it away. I also didn't want to leave phosphoric acid in any form sitting out on my property and exposed for any longer than a few hours.
Third, it is difficult to know exactly what concentration of phosphoric acid is actually in the Naval Jelly. Most of the producers list the phosphoric acid content as being anywhere from 10 - 30%. That is a huge range. So, it is difficult to know what concentration of phosphoric acid you are in fact using, which also plays a role in knowing how long to leave it sit on the steel. Using 30% could remove the rust in days, but 10% might take weeks.
Fourth, if you are having to use a lot of Naval Jelly, disposal can be a pain in the butt. In small amounts you can just wash it off on the lawn. For the number of wheels I was cleaning it would have killed my lawn. Washing it off on a concrete surface is not advisable either. Phosphoric acid is used to etch concrete. By using the liquid I could carefully collect the residue for disposal, or for reuse (which I intend to do because I got more of these wheels).
Lastly, Naval Jelly is crazy expensive compared to buying bulk concentrated phosphoric acid.