Oil Stain on Drive - Advice

Wondering if anyone can offer some advice, particularly if in the motor trade.
I'm currently trying to shift a pretty large stain of oil left on my concrete drive from years of vehicle use and have shifted about 50% of it through pressure washing, petrol soak & scrub, and used some of this commercially available fluid

http://www.homebase.co.uk/webapp/wcs...IVEWAY+CLEANER


I feel it needs something pretty toxic and aggressive now to get right into the guts of this staining and to lift it out of the concrete or to really break it up so it can be blasted off with the pressure washer.

So, anyone got any products to reccommend ?

Thanks in advance.

Caustic Soda. Or a Caustic soda based drive cleaner. But be careful because using it too concentrated may eat away the contrete itself.

C

I've heard that sprinkling it with a tub of bakers bi-carbonate soda and leaving over night can help. Not all concrete is the same though.

washing up liquid + water + stiff broom always worked for me.

[MrMessy]

Sprinkle on clothes washing powder and dampen with water. Leave a good while then brush with a stiff brush. Pretty caustic apparently will break down a body if left in a vat of the stuff

Originally Posted by injury_ian

washing up liquid + water + stiff broom always worked for me.

Almost the same here. A lot of washing up liquid, brush to work it in with little water, leave for a few hours followed by a blast with the pressure wash. Rinse and repeat if necessary.

a bit of science behind this.

If you use fairy liquid you are using a detergent to dissolve the oil into water for removal. Its only as good as being able to get the water into the concrete to dissolve the oil/detergent and back out again.

Caustic soda breaks down the oil (ironically to soap) so it doesn't rely so much on water to wash it out. It breaks it down and for sunk in oil it's the best way.

By the way, spray on oven cleaner is a really good caustic based cleaner and should do the trick for you. It may turn the concrete white initially.

C