I have a quick question. On a project car I am working on some spots were surface rusted (in pits) and I used Phorphoric Acid to remove it. I kept it wet and wiped off the residue before it dried. I then used water on it, to neutralize the acid and it of course surface rusted again basically instantly.

I got to thinking if it wasn't surface rust, but rather was iron in the water I used, causing the rust.

I then got to wondering if I could use something like distilled, purified or deionized water on it. With the deionized water especially the minerals are stripped out which I would think should be better.

Also, if one cannot remember where exactly on a panel the acid was used/dripped at on a vehicle, how should they neutralize it? My thought was to use a light coat on the entire panel I used the acid on and then remove it with water. I figure it is better to be "safe that sorry" and not guess wrong the exact section of a panel I used it on.


Thanks

I usually wash the panel with Dawn dish soap, rinse well,
and dry with a towel as quick as possible.
After dry, I go over it with sandpaper to remove the surface rust.
Then tack and get some epoxy on it as soon as possible.

delta1 wrote:I have a quick question. On a project car I am working on some spots were surface rusted (in pits) and I used Phorphoric Acid to remove it. I kept it wet and wiped off the residue before it dried. I then used water on it, to neutralize the acid and it of course surface rusted again basically instantly.
Thanks

Rewet the panel with acid, and allow it work a few minutes, then rewet and while the acid is wet and active, wash with dawn soap and water then quickly rinse and dry. You can't allow the acid to even start drying on the metal.

Sanding the panel will remove the flash rust, except in the pits, and epoxy will take care of the rest.