Removing paint from concrete floor

MichaelD

Lifer
Jan 16, 2001
31,528
3
76
More than a year ago I spilled an entire gallon of flat black paint on my garage floor. I literally kicked the bucket across the garage and the thing cartwheeled and paint went over probably 20 square feet of floor.

I sopped up as much as I could with newspapers. The very next day I went and bought many bottles of this acid concrete cleaner "guaranteed" to remove anything. It goes on liquid and you're supposed to let it sit overnight, which I did. The next day I had a ton of white dust that smelled like Drano and every drop of paint was still there.

We're moving soon and I need to get that crap off. I have a power washer, but I doubt that will do anything. What do I use? Stiff wire brush? The paint is "in" the concrete...it's not like chewing gum stuck to the surface. Metal paint scraper does nothing.

How do I get the paint off without destroying the floor?
 

MichaelD

Lifer
Jan 16, 2001
31,528
3
76
Not likely b/c it's not my house. Buying my own house, so that may be an option when I screw up my own garage, but not this one.
 

MagnusTheBrewer

IN MEMORIAM
Jun 19, 2004
24,122
1,594
126
I've used muriatic acid before but, it's a pain. I like the idea of painting and sealing the entire floor though. Perhaps those interlocking garage tiles?
 

DrPizza

Administrator Elite Member Goat Whisperer
Mar 5, 2001
49,601
167
111
www.slatebrookfarm.com
If your pressure washer won't take paint off a concrete floor, your pressure washer is little more than a fancy garden hose nozzle.

Muriatic acid ought to do the trick - don't bother diluting the stuff. Just pour it on straight, use an old push broom to spread it around, and let it sit 20 minutes. Then rinse off with a garden hose. Helps if you can hold your breath for a little while.


But, one of the best paint strippers I've used - it's made for removing paint from detailed woodwork - is more or less straight lye in a paste form. I don't know how it'll do on concrete though.
 

olds

Elite Member
Mar 3, 2000
50,096
771
126
Is the pressure washer gas or electric? Gas, you might get most of it. Most likely it's there to stay.
 

ponyo

Lifer
Feb 14, 2002
19,688
2,810
126
Latex flat paint is not durable. Pressure washer should easily get it off. Pressure washer can cut through concrete. Flat paint is nothing.
 

MichaelD

Lifer
Jan 16, 2001
31,528
3
76
OK, thanks for the good ideas. The pressure washer is electric and admittedly is not "pro-grade" but I can tell you that it has left skinny white lines on my back patio slab...it's not a toy.

Reason I've not used it in the garage/on the paint yet is b/c the garage is still full of all my tools/boxes/etc. I can't try the pressure washer until we move out a few months from now...I'm just being proactive by asking here. I would like to get some of my deposit back. Real shame, spilling this paint; we've kept the rest of the house pretty much immaculate.

I'd rather spend a few hours with the pressure washer "knocking down" the entire garage floor to a much lighter color, than losing my entire deposit, that's for sure.

I've got a starting point now. Thanks, guys. :)
 

Humpy

Diamond Member
Mar 3, 2011
4,464
596
126
That's the route I would go... except a more appropriate color?

It's not a ridiculous idea. In a similar situation I once took a chip of concrete to Home Depot for them to color match some paint. I faux finished some paint stains on the floor to look like concrete and then sealed the entire floor with a satin sheen sealer. It turned out pretty damn good and probably took a a while for the new owners to notice.
 

MichaelD

Lifer
Jan 16, 2001
31,528
3
76
Hmm, not sure if some of you are getting this. This is your standard, light gray-ish, unsealed concrete floor. Now imagine flat black paint, a lot of it, being soaked in over basically a 10'x10' area. It aint' pretty. There's no camouflaging this at all.

Did I mention THIS IS NOT MY HOUSE, I'M MOVING OUT AND THE OWNER WILL DO A WALKTHROUGH? I'm already assuming I will lose half my deposit, b/c that is standard operating procedure for any rental. You could rent a house or apartment for a year and NEVER live in it for even 1 hour, but they would still claim "wear and tear and you broke the blinds in the living room" and keep half your deposit. I consider the deposit lost money at this point. I just don't want to get a bill for $9,901.01 b/c they "had to replace the concrete in the garage" due to the "paint damage." It's a freaking garage; people will park their leaky car there, keep the dogs in there and use it for storage. It's not like a can of spray paint went off in the family room.
 

lsd

Golden Member
Sep 26, 2000
1,184
70
91
try paint stripper and then put a thin skim coat of concrete over the area.
 

Humpy

Diamond Member
Mar 3, 2011
4,464
596
126
Hmm, not sure if some of you are getting this. This is your standard, light gray-ish, unsealed concrete floor. Now imagine flat black paint, a lot of it, being soaked in over basically a 10'x10' area. It aint' pretty. There's no camouflaging this at all.

I think that wetting it with a water based stripper to soften what has soaked in and then hitting it with the pressure washer will be a good start.

Empty out the garage and get to work.
 

MichaelD

Lifer
Jan 16, 2001
31,528
3
76
I think that wetting it with a water based stripper to soften what has soaked in and then hitting it with the pressure washer will be a good start.

Empty out the garage and get to work.

This seems like the most logical solution. I will give it a shot when the time comes. Thanks, Humpy.
 

compuwiz1

Admin Emeritus Elite Member
Oct 9, 1999
27,111
926
126
Epoxy paint the whole floor in gray. I did this in my last house I built. It was really professional looking, like a shop. Anything that dripped was a synch to clean up.
 

balloonshark

Diamond Member
Jun 5, 2008
6,887
3,358
136
Epoxy paint the whole floor in gray. I did this in my last house I built. It was really professional looking, like a shop. Anything that dripped was a synch to clean up.
I was thinking the same thing.

If you use a power washer you better hang plastic to protect the walls and ceiling.
 

schmuckley

Platinum Member
Aug 18, 2011
2,335
1
0
paint stripper and one of these:

0905st_09_z+granitex_garage_floor_covering_from_vortex+floor_scraper.jpg


http://www.zoro.com/i/G1968486/?utm...hopping_Feed&gclid=CI_p3Nu38MICFUEV7AodZE4Avg

Maybe some gloves.