Removing rust marks from Indian sandstone (and general cleaning)...

[whoschuffed]

Hi all - just wondering if anyone has any experience with or knows what would be good to use to remove some rust marks I've got on one of the paving slabs on my patio.

It doesn't look like surface rust so not sure simply power-washing will do anything! (however I am going to try!)

If it makes any difference it is Kandla Grey Indian Sandstone - bit wary of using any kind of brick acid type product as I know this can royally mess them up. There are a few recommendations on here http://www.pavingexpert.com/stains.htm but nothing that directly relates to sandstone so didn't want to lob loads of vinegar or lemon juice on it and it end up wrecking it!

I am going to give it a power wash anyway this weekend but wanted to give the stain a seeing too if possible with some kind of cleaning solution, whether that is something like Jeyes or Patio Magic or plain old washing up liquid, or something a bit more specialist!

Any help is appreciated

 

[r896neo]

Rust is a pain to remove from paving and brick acid will not touch it. You need a specialist iron remover like lithofin bero or weiss rci

Kandla grey is one of the best indian stones in my opinion and i laid it at my own house. It will take bleach, mortar acid and pretty much anything else with no drama. Although always test on a corner first to be certain.

There are naturally occuring iron deposits in this and most other sandstones and the lithofin bero is designed for surface marks so may dull them but not completely draw them out if they are inherent in the stone itself.

 

[whoschuffed]

Luckily its only on the one slab so I think it is from when they have been stored they have been lent on something metal rather than it being something that has come about naturally.

Thanks for the two recommendations. The Lithofin Bero may be a shout and the Weiss says it is a deep rust remover however says it isn't suitable for some types of sandstone. Do we know if it will be OK on the Kandla grey?
The Weiss RCI doesn't seem as easily obtainable as the Lithofin either (not without paying extortionate P&P's).

In terms of giving the patio a general cleaning, would good old hot water, washing up liquid and a hard bristle brush be OK? Or is there anything better to use?

 

[r896neo]

Lithfin bero is definately easier to get as many tile shops use lithofin stuff and can probably order some. It is definately fine for use on sandstone.

For general cleaning i use hypochlorite. The 'rogers jollop' on the paving expert stains page you linked to.

Your marks very much look like they were caused as you guess.

 

[whoschuffed]

Thanks for the recommendation r896neo. Have just popped an order in for some of the Lithofin. Will give it a whirl at the weekend.

Will have to hunt down some hypochlorite - might just try it out with some bleach though in the mean time.

 

[r896neo]

Hypochlorite is now often available from builders merchants in 5 gallon drums. Its just much stronger and much cheaper than household bleach.