rajan2004 wrote:I'm using 3 teaspoons to 100ml so I guess around 18g to 100ml. Is that strong enough do you think? It has made a huge difference - does its effectiveness prove that rusting had taken place?
If it has made an improvement at that strength, (without sitting down and do a calculation properly) I'd say you are using it around 5:1 so it's not massively strong, but enough it seems to be removing at least the surface appearance.
Yes it does sound like what ever the stain is (Oxalic is a good rust remover) and from the results you are getting sounds more like "Rust" then natural iron content. From the photos it didn't look like a rust type stain, but if it is working for you then great, but as I said just let the paving over winter now, then if the stain has stayed away over the winter,problem solved, I'd give the patio a good clean come the spring allow to dry out thoroughly then seal, late April onwards would be your best time depending on how long winter lasts.
It's not a patio - our front garden path...actually we wondered whether the stone we bought was more suited to a patio as it's light grey and marks v easily.
Once it is sealed, do you think we can expect wet footprints etc to mark the path as it currently does? When it has been raining, the path really attracts a lot of marks which are v noticeable!
When you say "wet footprints" what do you mean? what a permeant mark? or it disappears once the paving has dried out? Sorry I'm a bit confused with that one.
Would definitely recommend sealing but you also need to understand that sealing is not a force field. Even when sealed your stone will still pick up marks. Sealing will prevent the marks from absorbing into the stone and therefore make cleaning and maintenance a lot easier.
Thanks Steve - I'll definitely get it sealed. The type of footprints I mentioned Roger are things like paw prints from cats which show up in the morning. They will of course be shifted when it rains but I just wondered whether sealing the stone means that marks like that wouldn't stay on the surface for long?
Just to update you on the Oxalic acid. It has made a huge difference on the path. I applied a little more again at the weekend and all of the lighter marks are gone but the darker marks are still there a little although not quite as bad. Given that there is obviously a rust issue - would it make any difference if, as a last measure, I tried using some Lithofin Bero to shift the remaining stains or is Bero the same kind of substance as Oxalic acid?