Painting a garage floor????????
I just painted mine 3 weeks ago. I used epoxy-base concrete floor paint (flakes optional and I didn't use them). The kit came with a acid etching solution to treat the floor. I would highly recommend using an epoxy kit - if you don't, you'll wish you did later. Also, if the floor has exist dirt, paint, etc on it, you'll most definitely want to get it off. Use a scraper or putty knife for the easy stuff. You can use a sander for the tougher stuff like paint. Once you get it clean, treat it with the acid etch then paint. Follow the instructions of the kit.
Etching it involves applying a muriatic acid solution on it, letting it fizz a while, then rinsing it and letting it dry. This leaves a dull surface for the paint to bond with. You absolutely need to go by the manufacturer's instructions concerning primer, and you also need to make sure that the coating you apply is compatible with car tires. Not all of them are, some of them will bond to the tires, and as soon as you park a car on the wrong coating, you will have four spots of damaged coating when you back out. Check out car magazines because they almost always have ads for garage coatings.
Etch it with Muriatic acid. Follow instructions. Rinse well and let dry for a day. Marine epoxy with sand sprinkled on top as you roll it out will be very durable and last a long time.Again, check the directions as you may need to primer first.You can even wipe oil up off of marine epoxy paint...
if your floor is clean except where you spilled paint. i would clean the paint spots real good and instead of painting it i would use the dye instead. concrete will not hold paint no matter what you try it will chip. i rolled the dye on my garage floor 5 years ago and it still looks good. i usrd the grey but i think there are other colors to choose from.
I'm thinking of painting mine too. We're going to first put down a self leveling paint to fill in the holes and cracks, then use a garage paint with cotton strands in it to make it slip-proof.