Re-painted workshop floor

[Frank S]

I tried to wash and paint the double car in my house before we moved in, but the original owner had two oil leaking cars in the garage and I'v tried everything to get the oil out to a clean surface. I only want to do the model shop area, a 20 by 15' area for better lite finding the small model parts I drop! I'll just not end up doing it now because I have way to many tools to move to do it,even if I could get oil spots clean!

Ok tere are several ways to eradicate an oil spot, none are going to be super fast if the oil spot had years of recontamination
A strong Alkaline detergent and scalding hot water scrubbed and scrubbed will bring out most oil spots.
The KBS kleen is what I use to remove oil on engine blocks or transmissions. it works great on concrete as well the stuff is pricey though However for best results with it you mix at about 10 to one in scalding hot water scrub it in blot it up reapply a couple of times then on the last application cover the wet area with kitty litter and lay a plastic sheet over that leave it for a few days then sweep it away.
Another way also much cheaper is to use Dawn Green or blue dishwashing detergent. scrub it in with 4 to 1 scalding hot water as in the process before then cover with kitty litter and plastic leave it a couple of weeks undisturbed.
Another way is after the detergent scrubbing is to pour acetone over the area and cover with kitty litter and plastic NOT RECCOMENDED in a closed confined area or near any possibility of sparks or flames
the last method detergent scrub and spend $35.00 for a 30 lb bag of U-haul oil sponge. spread and cover with plastic as before
The U-Haul oil sponge has oil eating microbes which will convert the oil into CO2 and water, there are no chemicals in the product
Cheap ground clay like is supplied for cleaning shop floors will do a good job of absorbing the oil over time but you need a catalyst such as Safety-clean solvent or something like the KBS Klean detergent
There is always the Amway concrete cleaner if they still make it. It was a great product but again pricey