[wpclean]

What is the best product to use for removing chunks of concrete on yellow block paving . . . I have looked at the brick acid products, but they advise not to use on coloured block ?

Thanks.

[Neil Jones]

I wouldn't say there is much you can use other than acid. Have you done a test patch? Perhaps try a weaker acid like phosphoric, Kev Martin sells it.

I think it's phosphoric anyway.

[Griffus]

Scrape the large chumks then soak with water, do this at pressure and shift any loose bits. Then try your acid for a few minutes. If you've scraped the majority away then the acid should help get rid of any staining.

Test a small inconspicuous area before hitting the main bit.

[wpclean]

Thanks for the replies, I have allready cleaned the drive, but noticed a couple of blocks with a lump of the stuff on each, will try the suggestions 

[Kev Martin]

Take it off with a Fein Machine fitted with a diamond rasp then finish with a cleaner buffered acid like Aqua Mix Xtreme
Kev Martin
Tiling Logistics Ltd

[wpclean]

Take it off with a Fein Machine fitted with a diamond rasp then finish with a cleaner buffered acid like Aqua Mix Xtreme
Kev Martin
Tiling Logistics Ltd

Do you have a link for the acid please Kevin ?

[BDCS]

http://www.tilinglogistics.co.uk/index.php?route=product/product&product_id=159

[wpclean]

http://www.tilinglogistics.co.uk/index.php?route=product/product&product_id=159

Many thanks mate