Customer has a 3 year old concrete driveway and a few months ago had a large spill of what he tells me is Power Steering Fluid. He tried brake cleaner and whatever degreaser he could find at the local big box store before he called me.
Went out to clean it on Monday with little success. I pre-treated with 50% EBC and let that sit for 20 minutes then surfaced cleaned (cold water - 8GPM, approx 2300 psi) a couple times. Treated again and surface cleaned a 3rd time.
Got out all the dirt, etc. in the driveway but the stain doesn’t appear any better. He also had big oil stain on the asphalt road in front of his house and that came out beautifully with the EBC and light pressure washing.
I could rent a 3.5 GPM, 3000 psi hot water PW and try again… What chems/process do you suggest? Is Power Steering Fluid special?
Here’s a pic from before I cleaned - don’t have a current pic but stain is basically unchanged.
He might have set that stain in with the degreaser and brake cleaner. But search oil stain removal. Try crushed kitty litter. Seriously. Oil stains are harder to clean up after you use chemicals on them. In my experience.
Isn’t that stuff mineral oil with added stuff to keep it from foaming up? Ide tell the home owner to kitty litter the hell out of it every day, grinding it into the concrete with his shoe like Sgt Majors about to inspect the motor pool on a friday. Let it set over night then repeat each day. Rinse it off at the end of the week.
You can also try a poultice - Prosoco makes one or you can research and make your own. Honestly this approach is better suited for a homeowner as it is a several day process and can take repeat applications.
It is like a peanut butter consistency mud that you put all over the stain area. Cover with saran wrap for 24-48 hours. Then uncover for 24 hours.
I idea is that the moisture in the poultice will soak down into the substrate (the saran wrap part). Then when the wrap is removed the poultice will dry out and pull that moisture back out of the concrete with the containment with it this removing the stain. It can take several attempts with each lightening it more and more.
I did it once on my own driveway and it did work, just that it took me 3 applications. I could see myself going to a clients house 2-3 times over 3 days and then repeat again for each application.
This is kinda like the kitty litter approach just a step or two up the ladder in effectiveness.
You might try Butyl which is good for dealing with these types of fluids.
My gut says to walk on this. Unless that homwowner is dead set on getting rid of it and paying you for all your trips, trial and error, then you won’t get it out and not get paid for your effort accordingly.
Heat will help, but the cost to rent for this again would have to be passed on to homeowner.
People say torch, but I am not sure about that method. Perhaps someone on the board with extensive knowledge on this procedure can chime in. My logic say burning oil on a driveway would do more damage than good.
