Cleaning / Prepping new slab for acid stain

[Mr. Demeanor]

I have decided on acid stain and seal for my new garage. This is a concrete block building and the interior walls are stucco. Between the masonry/block crew and the stucco crew quite a bit of splatter is on the floor. Although most was scraped up, there is a lot of staining from the material.
What is the best way to prepare the surface? Do I need to sand and with what grit? I don't want to grind into the surface.

 

[Mr. Demeanor]

I did stop at my local equipment rental shop. I've have read that the surface should be prepped with 200 grit but they only had up to 100 grit which sounds very course.

 

[Shea]

If you are planning on using an acid stain you do not want to grind the concrete. Acid stains are reactive. They require the free lime and other minerals in the upper surface of the concrete to react with to impart their stain. If you grind, it will remove most of this material and the acid stain will be very weak. You will need to use a solvent or water based stain if you grind.

 

[SolarColumbia]

I would try cleaning the floor with something to get the staining out. Don't use anything acidic, though, as it will interfere with acid staining it.

 

[Tpsykes]

Look into acetone stains, you can layer multiple colors to give it a nice look and can still grind for prep. A very popular floor right now