Old garage floor prep questions

[Lindsayspop]

I've read a lot of threads and alternate between being pumped about using epoxy to thinking I should just paint the floor with something that might hold up for a few years -- then do it again.
The garage floor was poured in the mid-50's and has several hairline and one or two 1/4 inch cracks that probably run all the way through the slab. At one time it was painted with a gray paint that mostly came off after power washing. Some is left around the edges. I de-greased areas of obvious staining.
Question one:
I plan to use angle grinder to open up the cracks enough to put some fine sand down to give the crack sealer a base to sit on top of. It looks like from what I've read I should use an epoxy crack sealer. If I do that will that dictate what sort of finish I can to put on the floor or do I do that step last?
Second question:
If I choose to paint the floor (knowing it will need frequent re-do's) can I paint over the old paint which didn't come up from power washing?
Question three:
If I need to remove the old paint (mostly around the edges) do I strip it or do I need to grind it off?
Any thoughts would be appreciated.

 

[nolimits76]

A flooring guru can give you a more definitive answer, but in general, the key to a good finish coat is excellent prep work. So if you re-paint I would remove the old paint. With your cracks, you could use sand to fill the voids to a point and then use a backer rod with joint sealant or possibly even a top coat of quick crete.

 

[Shea]

Always do the repair first and the epoxy crack repair will be fine for just about any type of coating you want to apply. If you have any concerns after that I would recommend contacting the manufacturer of the coating product.

If you are just painting the floor, then you shouldn't need to remove any of the older paint that would not come up after the pressure wash. It will be somewhat noticeable though when you paint over it. If you want to remove it then a paint stripper will work. Just make sure to clean the floor after using the stripper.

If you do plan on coating with epoxy, then you will definitely need to remove the paint first followed with at least acid etching the surface or preferably grinding in order to get the correct profile for the epoxy to adhere to.