Mortar stains on indian stone - the answer - How to get rid of stubborn mortar stains

[matt_north]

Hi All

I laid 50sqm of indian stone (Fossil Mint) a couple of weeks ago and once i had completed it realised i wasn't as careful as i thought i'd been in regards to staining the indian stone with the mortar. However i'm lucky enough to have a plant and tool hire company so had a range of equipment to solve the problem and thought i'd share it with you.

I tried an industrial pressure washer which for the most part did no good. I then used an angle grinder with a crimped wire brush cup, this removed the stains perfectly but left a metallic residue on the surface which came off with the pressure washer. Please note i used a CRIMPED wire brush cup not a TWIST KNOT wire brush which is far more aggressive.

Must admit i breathed a sigh of relief cos the next step was to go nuclear and bring the sand blaster home!!!

Hope this helps someone

[Tony McC]

You need to be careful with any form of wire brush as, on some paving products, they will leave visible scratch marks.

You did well getting no marks on Fossil Bloody Mint, which normally scratches with a fingernail, but that may be because you got to the mortar residue while it was still relatively soft.

Good tip, though!