Monday, January 11, 2010

What if I acid washed an area?

Ask a Pro


Q. - My wife and I have used your products before and were very pleased with the results. We're now finishing the other side of our basement and have everything already ordered and in hand to start staining. We had some water down there a couple of times that caused some rust stains in a couple of spots on the floor. I asked around at local paint shops and big box hardware stores and the consensus answer was muriatic acid to get the rust off of the concrete, so that's what we did.

It was diluted as per the instructions on the container, and it did remove the rust, but it also appears to have 'eaten' away at the top layer of the concrete where it was applied, as this is much more rough to the touch and you can see what's probably sand.

We're planning on staining tonight and I'm really not too concerned about it, but I wanted to check with you to see if there were any dangers in proceeding with staining these areas. Thank you.


Hello Kyle,

There are no dangers, though the acid wash is the worst possible thing you could have done when using concrete stain. However, the good news is that Concrete Camouflage brand of concrete stains will still perform in such a situation when most others will not. Yet it may not take the stain quite as well in that area now. Therefore you will likely need to go heavy in that area and/or plan on letting it dry completely and give it a feathered in second coat.
Also, the roughness will cause the concrete sealer to soak in much more than the rest of the floor, which could cause a dry looking area. So lightly spot seal that area with a coat or two first, and then seal the entire floor, including over those areas. Once you get enough sealer on, and once you get a couple coats of floor wax on, that area should smooth out and be not near as noticeable.