I have old oil stains on my concrete driveway from my leaky car, that I must remove soon. what chemicals and methods would you recommend to remove these tough stains?
Step 1. Buy some finely grained good quality absorbent cat litter. Sprinkle a generous amount over the oil stains.
Step 2. Grind the cat litter into the concrete with some force.
I usually just stand on it and use my feet with a twisting motion.
The cat litter is both abrasive and absorbent and this technique will remove most of the oil. Once you sweep away the cat litter you probably wont even see the oil stain because there will still be a very fine cement colored powder left over the stain. Leave this in place for a few more days or until rains.
Generally mother nature will wear away the remainder of the stain in about a year.
If you want perfection now (which is hard to do with a bad oil stain), after the cat litter, use a power washer then more cat litter, rinse, repeat etc.
This method uses no caustic chemicals. I really don't know what chemicals one would use on concrete oil stains because I've always successfully removed them with the above method. For rust stains, I have used muratic acid with excellent results.
Pour 1 large bottle of Dawn dish washing liquid on stains and evenly spread out with old broom or large wooden stick. Let stand at least 12 hours. Spray off with hose.
Coke and pour evenly over the spills. Wait for about 30 minutes and hose off.
Other items that work are:
Benzoyl peroxide
Solvents like kerosene
Muriatic acid
Gunk
Swab
[addsig]
i have a friend that builds "jet boats" you could eat off the floor i asked him how he kept the floor so clean with oil spills. he said he used gas......km[ Edited by kenmax on Date 12/28/2004 ]
Oil that is left on pavement actually eats away at the blacktop... I know that there is stuff mechanics use to soak up spilled oil, but that is only good relatively soon after the spill when the oil is still wet - the cat litter will work well in this instance, too. If the oil is old, most likely it has already eaten a bit away at the black top. The color where it spilled might be different because of this... Try all of the above mentioned methods, but if they fail, just get a sprayer and coat it with a layer of driveway sealant. This will give your driveway a brand new look...
Concrete is nothing more than a sponge. Oil spilt onto it will seep deep into the pores. The longer it sits the further it goes. On unprepared concrete immediate attention is the only hope of cleaning the stain. I'm sorry to say, but old oil stains will be all but impossible to remove. At best, you can get to the oil that is near the surface. You can try anything that desolves oil. The suggestion to let it set for a number of hours is good. As far as washing it off, don't use anything less than a pressure washer. I would pour boiling water down while I was washing. A hose is a waste of time. There are guys out there that pressure wash with hot water. You can try to look them up as well.
Good luck.
[addsig]
I agree that concrete IS a sponge, and as such, the oil seeps down. I've tried cleaning it with a 4000psi commercial pressure washer, and as it was mentioned, I got the top layers, but not the whole stain. I could have eaten a BIG hole in my concrete, clearing out oil stain as I went, but just didn't consider that very economical. lol
try gasoline. several times........km
Cat Litter.
Step 1. Buy some finely grained good quality absorbent cat litter. Sprinkle a generous amount over the oil stains.
Step 2. Grind the cat litter into the concrete with some force.
I usually just stand on it and use my feet with a twisting motion.
The cat litter is both abrasive and absorbent and this technique will remove most of the oil. Once you sweep away the cat litter you probably wont even see the oil stain because there will still be a very fine cement colored powder left over the stain. Leave this in place for a few more days or until rains.
Generally mother nature will wear away the remainder of the stain in about a year.
If you want perfection now (which is hard to do with a bad oil stain), after the cat litter, use a power washer then more cat litter, rinse, repeat etc.
This method uses no caustic chemicals. I really don't know what chemicals one would use on concrete oil stains because I've always successfully removed them with the above method. For rust stains, I have used muratic acid with excellent results.
Pour 1 large bottle of Dawn dish washing liquid on stains and evenly spread out with old broom or large wooden stick. Let stand at least 12 hours. Spray off with hose.
Coke and pour evenly over the spills. Wait for about 30 minutes and hose off.
Other items that work are:
Benzoyl peroxide
Solvents like kerosene
Muriatic acid
Gunk
Swab
[addsig]
i have a friend that builds "jet boats" you could eat off the floor i asked him how he kept the floor so clean with oil spills. he said he used gas......km[ Edited by kenmax on Date 12/28/2004 ]
i have always used Tri Sodium Phosphate. I just sprinkle it on and let it sit until the rain comes and washes it away.
Oil that is left on pavement actually eats away at the blacktop... I know that there is stuff mechanics use to soak up spilled oil, but that is only good relatively soon after the spill when the oil is still wet - the cat litter will work well in this instance, too. If the oil is old, most likely it has already eaten a bit away at the black top. The color where it spilled might be different because of this... Try all of the above mentioned methods, but if they fail, just get a sprayer and coat it with a layer of driveway sealant. This will give your driveway a brand new look...
Good Luck!
[addsig]
Concrete is nothing more than a sponge. Oil spilt onto it will seep deep into the pores. The longer it sits the further it goes. On unprepared concrete immediate attention is the only hope of cleaning the stain. I'm sorry to say, but old oil stains will be all but impossible to remove. At best, you can get to the oil that is near the surface. You can try anything that desolves oil. The suggestion to let it set for a number of hours is good. As far as washing it off, don't use anything less than a pressure washer. I would pour boiling water down while I was washing. A hose is a waste of time. There are guys out there that pressure wash with hot water. You can try to look them up as well.
Good luck.
[addsig]
I agree that concrete IS a sponge, and as such, the oil seeps down. I've tried cleaning it with a 4000psi commercial pressure washer, and as it was mentioned, I got the top layers, but not the whole stain. I could have eaten a BIG hole in my concrete, clearing out oil stain as I went, but just didn't consider that very economical. lol