Help with acid spots on concrete floor

[ncfireman1918]

Apparently I did something kind of boneheaded. I am swapping an engine in my 1965 Chevy II, and while it is out, I've been doing some cleaning up and painting. I picked up some Purple Power DeRuster at the parts store, with the intention of using it on some of my lightly rusted parts that are not visible when the car is together. The product worked like a champ, the problem is where the overspray hit my concrete floor in the garage. I now have white marks everywhere the liquid hit the floor. Looking at the MSDS, I assume that is some light acid etch from the phosphoric acid in the spray, or something along those lines. Would have been nice to see a mention of the acid somewhere on the jug. I guess I should assume any rust converter would contain acid. Does anyone have any thoughts on what might remove these spots, or at least make them less noticable? The floor is bare concrete, as I had planned to put epoxy down when we built the house last year, but the timing didn't allow it. I am planning to put down either VCT or RaceDeck at some point, so it will eventually be covered, but I have to live with it until then. Thanks!

Chris

 

[LegacyIndustrial]

Try mixing some baking soda and water, agitate with bristle brush and rinse.
Should help.

 

[theoldwizard1]

Try mixing some baking soda and water, agitate with bristle brush until it stops foaming and rinse.
Should help.

If it was a spill that seeped into the concrete, you may have to repeat or allow to dry over night.

 

[ncfireman1918]

Sweet. I'll give it a shot. Anything has to be better than the spots I have now. The wife is gonna kill me if I make a permanent mess of my one year old garage floor.

 

[AlphaGarage]

Not familiar with the product, but if it does have a light acid or bleach you may be up a short creek. The chem not just only removed some dirt & crude, but it may have interacted with elements of the concrete and actually lightened or changed their coloring. If that's the case possibly the only way to make them less obvious is to likewise lighten the surrounding area, or darken the spots with some kind of coloring, literally rubbing graphite, shoe polish, oil, dirt or whatever makes them blend in.

But start with the easy solutions, try a cleaning with Simple green, try the baking soda etc...

 

[Edger]

A customer asked us to use phosphoric acid to etch their floors once and it did a very poor job of the hard concrete. I found it very hard to remove the residue with high pressure water too. Good luck, those stains are very difficult to remove, you are gonna have to face the missus!