Solvent stripping and relaying the worst....
Chris
Did you try the 3 step approach in the original topic I replied to, for the paving you are talking about in Ireland?
Yep it was more your 2 step approach as I had no HF.
70% of the stain came out but due to the almost white paving it's no where near enough (the DuPont flouropolymer is completely invisible on the surface so we cannot disguise any imperfections) . Just to make matters worse anything that is used needs to be biodegradable for the rain water gutters.
My mates mixing something up in his shed. A solvent that will penetrate the stone better(taking the surfactants with it) and although not biodegradable it evaporates about 30 c so it will never make it to the grid.
You might be able to the last 30% with this,
http://www.steintec.co.uk/product/146/WEISSGRI use this and it is good, as usual not a cheap product, might be worth seeing if they will send you a sample, they do, do them. Let me know and I can give you names to speak to at Steintec if you want.
Not completely what you might be asked to supply re the gutters, but I think you might struggle to find a completely Bio product to do the job.
Time you have flushed/cleaned off the concentrate will be diluted down to a minimal amount.
There is a MSDS sheet on the site for the product.
