drivewaysealer
I just finished power washing my driveway after scrubbing it with Krud Kutter oil remover solvent. The stains are better, but they aren't all the way gone.
Will the presence of these stains prevent the driveway sealer from adhering? I've given a good 5-10 min scrub to each bad spot with a deck brush and Krud Kutter concentrate. Should I go until it's spotless? I just want the sealant to stick!
First fix the leak! Then attack the stain with a bristle brush and some dish detergent; if that doesn't do it, there are commercial cleaners for asphalt or concrete, like this that are a bit stronger. Don't expect 100% results, but the stain will fade over time:
I've always used cat litter. It's absorbent enough that it tends to pull the oil out of the concrete. Not sure how well it would work on a stain once it's set in for a while though, but it's cheap enough that you don't have much to lose by trying.
Best Answer
I sealed the drive about 7 weeks ago now and it seems that the work I did cleaning the oil spots was sufficient.
My unprofessional conclusion from this experience is that if a power washer AND solvent AND 20 minutes of scrubbing doesn't get it out, it's probably a permanent part of your driveway now.
I'm pretty sure that the asphalt beneath that stain is actually imbued with the chemicals that cause the discoloration. I cleaned off what I could and the sealant stuck just fine.