Best way to clean a concrete floor?
 

My garage will be empty later this week for the first time in 15 years and there are some paint overspray and oil/brake fluid stains that I'd like to clean as best as possible, I'm not expecting miracle's. I've heard Muriatic acid is the best thing for cleaning but I don't know, I won't be painting the floor or putting any covering on it. What did you use and how were your results?
Finn

I've used both a pressure washer and the diluted muriatic acid methods. Both worked well.

I'm sure you won't be able to get the oil based stains out completely. You might be able to get them cleaned to where they are just a shadow. For myself, I wouldn't want to use any type of HCl on the floor. It will leave a satiny finish that will attract dirt & stains even more.

Hcl^^^ intense.

I use a absorbent to attract the oil in my garage then hose it down and dry it. Simple organic/inorganic process.

I's spray the bad bits with engine degreaser then wash it down with sugar soap and a broom. Then rinse well.

There's a product granite installers use to extract oil from granite or stone surfaces. I can track down the product for you if you like, because I have to call my stone installer. I have used it once, with pretty good result. I am not sure how well will it work on concrete and engine oil but that what I would use?

Take a little powdered detergent such as Tide and apply it liberally to wet concrete. Scrub it in well with a stiff-bristled deck brush and allow it to work for a few minutes, then rinse clean. Works like a champ.

Try Dawn dishwashing soap on the oil stains ... just as good as any commercial degreaser.

Brake Kleen is a great spot degreaser.

Brake cleaner. You may want to use the non-chlorinated version. Scrub brush for real gooey/black spots.

Carter

Brake cleaner of Varsol and then cover the stain with a plastic sheet for a few days. Then acid or TSP on the entire floor.

+1 for using Dawn. Removes most grease and oil pretty well.

If there is a puddle, a little kitty litter will sop up most of the wetness. Sweep it back and forth until the puddle is gone. Then wet the area with water and scrub the stain with dawn and a bristle brush and rinse. Repeat until the stain is gone.

For the paint stains try either an abrasive or "goof off."

Attached or detached garage? Any open flames or heaters?

even a 10% muriatic to water solution will etch your concrete. I use muriatic acid full strength to dissolve splatters on walls/bricks when pouring pool decks and clean trowels and floats. just a drop on concrete will dissolve and discolor the top layer(cream) where that drop lands. your concrete will never look the same. I use the 10% to etch before doing any spray deck. you might could try some xylene on a test spot.

If you not going to do a coating, don't over think this. Just use soap and a scrub brush on a stick.
Rinse and go on with life.

I would coat it with boiled linseed oil and varsol after it's clean.

Kitty liter and scrub with a 2x4 in circular motion, you will be amazed ,the oil stains will all but disappear and the concrete will look like new. No need for soaps and acid.

Try a small area, with a 12" piece of 2x4 and scrub, you wont be disappointed. If you like the results, just drill a hole in the 2x4 and install a long broom handle and go to it. Will have to increase litter as the old stuff get dirty. This is what we used to do inmy auto shop in high school and I still do it today in my own shop

Don't use acid. Wish I heard that years ago. Got a nice rough patch where i was trying to take off a rust stain...

Krud Kutter full strength, several applications over a week period, rinsed with hot water. You may need to mix TSP in with the Krud Kutter, but I've used it for oil, brake fluid, transmission fluid, etc... Always works and is non toxic...

Sorry to hijack.

Will any of the above methods work on interlocking brick that had transmission fluid leaked onto from a broken line?