I recently had a garage built and would like to put a finish on the concrete slab. I Do not want oil or anything else to get absorbed into the concrete, and I would like to hide some little cracks that have popped up too. I've looked at the hardware store and found a few things that want the concrete to be prepped with acid. What is that about? I also want to cover up the cracks that have popped up. Any suggestions on what to use??? Thanks for the Help.