[Roland S]

Hi I did a drive last week - one of the whiteish granite style block paving with the sparkly bits in. It had a really bad rust stain that was very big 2m x 2m that I managed to get rid of most of it and it was very faded what was left with oxalic. However I was driving past yesterday and noticed that it had reappeared, it hadn't 4 to 5 days after cleaning when I went back to resand. It's not as bad but very noticeable.Has anyone had this before with rust stains reappearing, I've had oil stains reappear and continue to come out but I was wondering if this is normal for rust stains?

[BDCS]

Is it rust or fertiliser

[Roland S]

she thinks it was rusty water leaking from her radiator, or that's what she says, i'm not sure if that's where it came from though. there's no grass at all in the front where the drive is so no i don't think it's moss killer (ferrous sulphate), if that's what you're thinking?

[BDCS]

You've done what I would have. Was it the car radiator or one out of the house

[Kev Martin]

Vary normal for rust.  You will be better using an acidic cleaner this time rather than straight forward Acid.

Try this

http://miraclesealants.com/c_hdac_nm.html

Kev Martin
Tiling Logistics Ltd

[Roland S]

You've done what I would have. Was it the car radiator or one out of the house

Car radiator or so she said.

[Roland S]

Vary normal for rust.  You will be better using an acidic cleaner this time rather than straight forward Acid.

Try this

http://miraclesealants.com/c_hdac_nm.html

Kev Martin
Tiling Logistics Ltd

Thanks, i see that's hydrochloric acid, although I described the blocks as granite they only have a granite face pressed onto a concrete block so I'm not sure how they would handle something that strong. These are the blocks they're getting quite popular now i've cleaned a few drives with these http://www.marshalls.co.uk/commercial/block-paving/products/mistral-textured-granite-sett-paving-webfa050410 i have some brick acid so I might try a test on a sample block before attempting anything on their drive. The blocks are almost white and if anything goes wrong it will stand out like a sore thumb.

[Kev Martin]

Then try a buffered acid with a cleaner instead

Kev Martin
Tiling Logistics Ltd

[chris scott]

Try Sepiolite Clay and Oxalic  mixed together to form a poultice. This will "draw" out the staining...long winded and pain in the ar  se but it will work.

[Roland S]

Try Sepiolite Clay an Oxalic  mixed together to form a poultice. This will "draw" out the staining...long winded and pain in the ar  se but it will work.

That's interesting thanks Chris.  The customer had tried oxalic before calling me but hadn't rinsed it and let it dry on the surface which in itself had created staining. Would leaving it on with a poultice risk more of that or will the poultice prevent it drying out and stop more staining do you think?

[chris scott]

The poultice "draws" the stain to the surface.  I have never experienced staining cause by the poultice itself.
You need o be aware that this method requires several application to completely remove the staining...so price accordingly!!! It is a different league of cleaning ...more restoration of hard surfaces...the cost can go through the roof to get the required results.
The stain will also look worse initially as it come up to the surface...similarly to what you are experiencing now .

[BDCS]

Why mess about so much if you know exactly what the blocks are and they are readily available ? I'd just chop them out and replace with new - guaranteed results and cheaper than mucking about with maybe treatments

[Roland S]

Why mess about so much if you know exactly what the blocks are and they are readily available ? I'd just chop them out and replace with new - guaranteed results and cheaper than mucking about with maybe treatments

Yeah that would be the most effective way. There's some matching slabs around the border with the same issue which would be more hassle. To be honest the job is done and I've been paid but if there was something I could just here was something quick and easyi would give them a knock and try and sort it for them. But I don't want to get too involved working for nothing.

[Kev Martin]

Try Sepiolite Clay and Oxalic  mixed together to form a poultice. This will "draw" out the staining...long winded and pain in the ar  se but it will work.

Chris

This method works well especially if you mix the poultice powder with the correct cleaner for the stain.  As a matter of interest have you ever done it?  If so where did you get the sepiolite from because the last time I tried to buy it I had to purchase a minimum 2 Metric Tonnes of the stuff

Kev Martin
Tiling Logistics Ltd

[chris scott]

Try Sepiolite Clay and Oxalic  mixed together to form a poultice. This will "draw" out the staining...long winded and pain in the ar  se but it will work.

Chris

This method works well especially if you mix the poultice powder with the correct cleaner for the stain.  As a matter of interest have you ever done it?  If so where did you get the sepiolite from because the last time I tried to buy it I had to purchase a minimum 2 Metric Tonnes of the stuff

Kev Martin
Tiling Logistics Ltd

My mates shed.