Another Epoxy-Coat Adventure

[StudPuffin]

Hi all! I'm new to the board but have been lurking for about week reading up and checking out everyone's awesome garage-mahals.

My wife and I just bought our first home and my stipulation that the garage be the first project has managed to stay intact so far. I've torn down a non-permitted room that had halved the floorspace of the 500sqFt and stripped the paint off the floor as best as I could. Then I finished out the walls with drywall and installed a new garage door opener. The next leap forward is the epoxy flooring. I've ordered one full kit from Epoxy-coat so I hope I'm close to going the last mile.

My concern is the remaining paint on the floor and the patching I've done to fill the holes left by the stud screws. I power-washed the hell out of the concrete and used Krud Kutter to degrease/clean it and the pores of the concrete already look pretty open. I have two spots that still bead water that I'm hoping the etching process will take care of. I used pre-mixed concrete patch in a bucket to fill in the holes and gouges in the floor but I'm concerned the etching process might dislodge the patching.

Knowing that the preparation is key, am I in good position to go forward with the etch and hope all is well for the epoxy? Should I see about a concrete grinder to remove the remaining paint and any potential oil spots? Will my patches stay in place during the etching process? I've included a picture so you can get a general idea. Any help is appreciated! I promise to post lots of pics during and after the process. Thanks folks!

-A!

 

[AlphaGarage]

Muriatic acid etching works primarily by dissolving the calcium in the concrete, it won't necessarily do anything for a lot of stains and oil spots.

If it does dislodge the patch work, then the patch work is pretty weak, better find out now rather than after you coat the floor.

Try just sanding down those few spots were water isn't soaking in, use a block or palm sander, or a angle grinder. No need to grind the whole floor if the rest of it's okay with just an acid etch.

 

[StudPuffin]

Thanks AlphaGarage! I'll take my belt sander to those trouble spots tomorrow after work. I mentioned the patches because I wasn't sure if the etching bubbles up, potentially causing the patches to hydrostatically lift from the concrete. I think it will be fine but I'm just super cautious. If I had the budget, I'd have re-poured the whole lot to be on the safe side. Wife would have my head on a stake though. . .

 

[AlphaGarage]

Couldn't blame your wife if you had done that!

If the acid could get underneath the patches, because they were real small or porous enough to allow the acid to slowly seep through, then it might dissolve enough calcium to get the remaining material (old sealer or whatever) to release because it has nothing left to cling to, but odds are that won't happen. There's also a chance that whatever is there would be sensitive to the acid just by itself, but again, that's unlikely. However if you want there's not much harm in applying some muriatic to those areas and seeing what happens.