Stone Paving Slab Lightened my Oxalic Acid

[fidaleo]

Hi

First post on this forum

I used a mild soln of oxalic acid and water to remove some really bad rust stains on a sawn wood fence due to non galvanised nails being use..this has worked a treat so many thanks to the forumn for this.

In the process I knocked the soln over onto a flag....doh.....I didnt realise for 5 mins and when I did washing it off and scrubbed it wtih washing liquid.

It now looks markedly lighted than the rest of the patio which is pretty large and I'd prefer to lighten the whole patio flag area.

Any idea how I can darken the flag and surrounding area to blend in more with the current paving

Thanks

Martyn

[KitchenGuy]

You have etched the surface of the slab by the looks. You can mess around with darkening it with dyes but time and the winter will most likely do the same job for you if you have the patience. Natural yogurt was a favourite for speeding up the ageing of natural stone. Lichens and algae seem to love it which effectively what most of the dirt on the patio is. Not sure how it will work on an old patio slab but with the low cost it could be worth a trial.

[fidaleo]

You are probably right..about me needing to just give it time....I'll give that a go

Thanks for the advice