>Have any of you had success cleaning and painting a cement floor after
>years of heavy use?
It wasn't "after years of heavy use", but I've painted a floor or two after
cleaning them thoroughly. I've appended below an article I wrote for a
club newsletter several years ago. It doesn't mention them, but there are
some brand-name concrete cleaners that evidently do a nice job, too. Check
out your hardware store for these.
Lee M. Daniels Laboratory for Molecular Structure and Bonding
daniels@tamu.edu Texas A&M University
'74 TR6 '77 MGB http://acs.tamu.edu/~lmd1191
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Painting your garage floor is like painting your car. You get out of it
what you put into it. No preparation, quickie job = poor results. But
spend the time to do it right and you'll love it.
I was lucky. Four years ago we had just moved into a brand-new house with
new white concrete on the garage floor, so my prep job was not the real
gorilla it could have been with an old, dirty, oil-soaked floor. But I did
the careful prep anyway. I had always wanted to do it, and here was an
ideal situation for it.
Just as in painting your car, the secret is in the condition of the surface
before the paint goes on. Cleanliness! Even though the floor was
relatively new, several weeks of my cars and the builder's various vehicles
had already made their marks on the virgin concrete, so the first order
was to get the oil stains off. As I have written here previously, the very
best way to do this is with a bag of kitty litter---the kind you can get at
Wal-Mart for $1.98 works just fine. You can also buy 50-lb sacks of the
same material, usually called something like "Oil-dry" or the like, at auto
parts stores for $4 or $5. Pour liberal amounts of the kitty litter on
each stain, and then spend several minutes grinding the pellets into a
powder with a hand-sized block of wood (I use a 2x4x4). The grinding
action gets the powder down into the pores of the concrete, where the stuff
soaks up the oil/grease/grunge very effectively. Then you can sweep or
vacuum up the dust, and you should have a nice white spot where there was
once oil.
Once you are satisfied with the cleanliness of the floor, it's time to do
the etching. You'll need a diluted solution of muriatic acid (HCl
solution). You can get the acid at a pool supply, hardware store, or
chemical/cleaner supplier. Mix one part of the acid with 10 parts water in
a plastic bucket, then pour and spread the solution all over the floor.
Spread it quickly, because the reaction is fast and you want to be sure
that you get unreacted HCl over the whole surface. In other words, once
the solution hits one spot on the floor, most of the acid in that puddle of
solution with react before you can spread it somewhere else. You'll know
that it's working. But don't do this in a closed garage - the fumes
evolved are noxious! You'll see lots of bubbles and hear a lot hissing as
the reaction goes.
Once you've covered the floor with the acid, you can rinse it off with pure
water within just a few minutes. After it's perfectly dry, you'll want to
sweep it completely. And then again. And probably another time. You'll
notice that you're sweeping up a lot of concrete "dust" created by the
etching process. And, just like a car, you want the surface .. (all
together now)... CLEAN! You will now have a clean, grease-free,
"roughened" surface that will hold your paint very well.
The very best, but also most expensive, way to go is with a 2-part epoxy. I
went the cheaper way with a good-quality floor paint recommended by the
dealer. I also bought a container of sandy stuff that you mix with floor
paint to give it more texture so that it's not so slippery. A painted
concrete floor can be *really* slippery, especially with a little water on
it. If you have a spouse, friend, kids, etc. who will be walking through
your garage, you definitely want to add the texturizer. I don't know the
best way to apply the epoxy, but the floor paint went on very well with a
roller. I just had to keep stirring up the paint in the roller pan to keep
the texturizer suspended. I did two coats, and the results were great.
Four years later I'm still glad I did it. Anything that spills on the
floor wipes right up without leaving a stain. Sweeping the garage is a
*lot* easier; dirt just doesn't stick. There is one small spot where a few
bits of paint have flaked up, right under one of the car tires, but that's
no problem compared to the ease of taking care of the rest of the floor.
If I ever move to another garage (with a house attached), guess what I'll
do before unpacking my tools?
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