Cleared out/threw out a lot of junk, degreased floor a million times, rinsed a million times, powerwashed a million times, etched with muriatic acid, neutralized, rinsed a million more times. Have been prepping the floor for days off and on. Note that I pushed a lot of "good junk" to the back of the garage which is a slight step up from the parking surface. I will not be coating that surface with epoxy. Instead, I will lay down VCT. This garage is a huge project with many more things to be done after the flooring is complete (putting in 220V service, painting walls, rearranging big time, perhaps some wall cabinets, good lighting, and eventually a sink).
This is a 40 year-old slab that has seen its share of oil, paint, glues, and anything else you can imagine. After days of prep it is pretty darn clean. In several cases I had to mechanically chip away at dried drips that wouldn't come off any other way. These trouble spots included some epoxy drips that I used to refinish an old rifle. The others included gorilla glue (amazingly stubborn stuff), and oddly enough some oil-based paint drips. These trouble spots just laughed at my 2500 PSI pressure washer, degreaser brush agitation, and even the acid.
Still waiting for it to dry from working until 2am. Wish I had one of those propane torches that hooks up to a propane grill tank so I could gently "lick" the wet areas and dry them out. Tried a hand-held heat gun and it works great, but I might be out there for days because it is slow-goin'. Oh well, no sense in getting in a rush. The darker areas are where it's still wet:
