Kandla Grey Indian Sandstone rusting -

[marblehead1]

Hi guys,

Hope you're all well. I'm new here and searching for some advice and found this to be the best place so I'm hoping you guys will be able to help me out.

Recently, during lockdown etc. I've decided to do my patio at home with Kandla Grey Indian Sandstone. I found it helped me during lockdown and took my mind off everything (I had some personal issues to deal with and lockdown really didn't help at all.) I'm not scared of labour at all and found it really interesting. I learnt a lot. I've never done anything like this before but I studied a lot of videos and asked a lot of questions to people I know that are in the trade. I thought why not give it a bash myself and off I went.

I have done everything correctly. I dug out, laid a membrane, hardcore, vibrator plate etc. so it's all okay in that sense. I laid the flags on a full bed as advised and I was really pleased with the patio, it looked great.

However, before I came to seal it, I decided to clean it just once more before applying the sealer. To do this, I stupidly used brick acid which I now know is a big no no (sorry!). This has caused what I've found from research, rust to appear on the flags. I cannot get them to shift at all. I've tried everything, bleach, washing up liquid, all sorts! The only product that I have found does help is the following:
https://www.amazon.co.uk/Owatrol-Net-Tr ... 8983&psc=1

The Net-Trol appeared to help and I thought great so decided to buy some more to do the rest with it. Before I got some more, the stains started to reappear. I tried again with the Net-Trol but again, they just seem to come back. Is this because I am not sealing them immediately after?

Anyway, do you guys have any suggestions? Have you had this before and if so, what can I do to get rid of them? I'm absolutely gutted as I worked hard on this and was really proud of it but now I'm annoyed with myself for using brick acid on them and ruining them.

I'll post some pictures so you guys can advise. Any help is greatly appreciated so thank you in advance!

[marblehead1]

[lutonlagerlout]

the deed is done alas!
in your current situation I would stop putting more chemicals on the stone and just let the glorious british weather do its job
the installation looks great,and IMHO Kandla is one stone that doesnt really need sealing
its very hard
cheers LLL

[RAPressureWashing]

Why ho why do people reach for brick acid!!!, anyway you could try LTP's rust remover, non-acidic but may not be completely successful as the damage is already done, I've used it many times and it works, but you've triggered the natural iron content of the stone so you may not get 100% success as in it may well return.

Link to the product https://ecoprotec.co.uk/product/rust-stain-remover

[marblehead1]

Hi, thanks for your suggestions guys. Really appreciate them.

I know I shouldn't have used the brick acid but I didn't realise until I had already used it. I've never done anything like this before so it was a bit of a rookie mistake! Do you recommend that if I get the stains removed one way or the other, to immediately seal the stone after? Will this prevent it from coming back or not?

Thanks again for your help.

[RAPressureWashing]

Sealing the stone will not prevent the iron staining from coming back, I'd try the product I suggested see how you get on, leave the paving a couple of weeks to see if more staining starts to come through, you have a stain "in" the paving not "on" so it may well have to run it's course until it stops, also personally I really don't see much point in sealing Indian Sandstone, just a yearly clean