[drive surgeon]

hi guys, a custy has a tarmac drive, he had a load of rust and oil stains on it so he coated the drive himself with thompsons drive seal (tarmac, back to black paint?  but now when it rains the patch where the oil and rust was shows badly, the water sits in pools where the oil was and the rust comes through in big orange patches.

what should i use to remove the rust (phosphoric acid)?
i will use strong detergent to get oil out but the trouble is they are underneath the coating so dont know if it will come out,

i told him iwill try to get it out then he will have to re coat the area.

also has anyone used this thopmsons drive seal for tarmac?  is it as good as swiss seal back to black or others?  cheers guys. :

[steve_doyle]

Not the help you want but lifes to short for these nightmares.

Big swerve for me.

[BDCS]

The bitumin used in tarmac drives is ruined by oil unless it is removed there and then. The reason the puddles are where the oil was is because some material has gone. If the rust has been overcoated and comes back it will remain there. Answer is to get the drive re-surfaced - I would'nt even bother working on it

[drive surgeon]

is it phosphoric acid used on rust? if so where do you buy it?

[mark.laycock1@ntlw]

hi ld you send me a photo plese

[drive surgeon]

will try get a pic mak>

[drive surgeon]

im gonna give this a go, will tell the custy im not 100% it will do the trick.  i will apply a degreaser , then wash off, then try apply some phosphoric acid to remove the rust and then wash off. he can then apply some black tarmac paint to cover it up.  if it does not work then so be it but i need the money so will give it a try. :

[mark.laycock1@ntlw]

i use a think paint i can get you some if you like £100 for cash 25ltrs

[BDCS]

don't leave the degreaser on for any time

[drive surgeon]

never heard of think paint park, where did you get that?

[mark.laycock1@ntlw]

its thinker then the paint you get from wickes,swiss seal

[drive surgeon]

not sure about "thinker" paint, never hear of it?  will try to use tfr and toilet cleaner on the drive to shift the oil abd rust. 

[drive surgeon]

not an easy job guys!

i used tfr to try to remove the oil. the rust was right down to the grey tarmac underneath. the back to black came off where i had cleaned. he knew this would happen anyway. the rust would not budge.  i told him to try to seal the rust in and then coat over with tarmac paint and the rust should not come through.


its amazing that it seeps through the tarmac paint to the surface!

[Griffus]

I see the job is done but for future reference: -

Rust is easily removed by soaking affected area with water then applying a small amount of Masonry Cleaner or Brick Acid (Hyrdochloric Acid based; Acid content usually varies between 8% and 35%). For small areas apply with a paint brush but be sure the area is well and truly watered prior to applying the acid.

This is very nasty stuff and you must use full PPE: -
Chemical Goggles
Chemical Gloves / Gauntlets
Chemical Respirator
Full Chemical Suit with Hood
Chemical Wellingtons

I have never used on tarmac though, nor would I as I suspect it would completely trash it.

If in doubt speak to your supplier or even tne manufacturer.

As with all Chem's remember COSHH assessments.


Best Wishes