Sandstone flags - Problem discolouration

[SEALENT]

Having sealed Sandstone with Thompson (Ronseal) seal have whitish discolouration, they say use white spirit, Any answers

[Pablo]

Hi there I'm sorry to say this but you're up the creek on this one. Only time will help here usually 3-4 years. There is no way of reversing the effects of the sealant now as it has impregnated the stone. Did you do it or did your contractor and was it done recently. Just a heads up no contractor of sane mind would put sealant near paving at this time of year some water based sealants are ok but don't give any discernable visual finish so you have to put another on when he weather warms and drys up.

[Tony McC]

...and that particular brand is one of the worst culprits. It may be because it's such a large seller thanks to it's distribution through DIY sheds, but about half of all the 'concerns' regarding sealants that come in by phone and email involve Thompson's Patio Ruiner. There really ought to be a big strap across the tin saying "DO NOT USE IN WET/DAMP/SLIGHTLY MOIST WEATHER".

I've heard this alleged remedy of using White Spirit before, but no-one has ever shown me a patio, or even a single flagstone, that has been fixed by using this method. The only cure that I know to be 100% effective is replacement of the treated paving.

[SEALENT]

Great to hear from you guys, unfortunately as amatures , but lovers of natural stone , we have sealed in catostrophic damp weather, we have learned the hard way, its the trying to fix it ,thats been so difficult, but I have to say without this site we would have been helpless, Thanks a lot. Been to our suppliers 2day, they have recommended ? Brick cleaner ? what you think Bon we

[lutonlagerlout]

no brick acid ,wait till dry weather then lithhofin mn stainstop
LLL

[Tony McC]

Brick cleaner will make it even worse!!!! Who is the eejit supplier spouting this tosh?? They need to be drummed out of the trade.

[msh paving]

straight to the point there tony MSH

[SEALENT]

Yes, a lot of conflicting stuff being sold to us, I think we will have to leave the patio as it is for the moment in case we do drastic damage, weather is drying up here in Ireland, so maybe things will improve. Latest product we have been advised to use by is DRYTREAT, but as we have already 'sealed' would be terrified to try it.

[Tony McC]

DryTreat is very good, but it can only be applied to untreated stone. You can't apply it over an existing sealant or colour enhancer.

[SEALENT]

Thanks for all thts.

[SEALENT]

Thank for all the help:)

[RAPressureWashing]

As Tony has stated and I agree with him Roseal/Thompson's should just a have a warning "Do not use this product it's crap"
Also brick acid is not going to help.
We have sucessfully taken off sealers that are acylic by washing but then we use heat up to 240+ degrees so basically melting the stuff off.
If the sealer has really soaked in then that's a different ballgame.

[87-1235666499]

The best way to remove any acrylic sealant is by using a solvent such as Xylene. Broom the xylene onto the slabs (using a natural hair broom not plastic or the bristles will likely melt!) and after a few minutes the acrylic will soften - vigourous brooming will help this.

You will then need some old rags to wipe off the solvent / acrylic mixture.

A bit messy but it will work, acid will not. The only other alternative would be mechanical abrasion and that is messier and more expensive.

You can get xylene and some decent sealer to replace the Thompsons with from a company such as Adseal on www.advancedsealingsolutions.co.uk.

[lutonlagerlout]

btw welcome to the brew cabin WoP
you seem to know some useful stuff
LLL

[87-1235666499]

Hi LLL,

Many thanks for the welcome, been lurking for a while so have enjoyed some of your posts.

I've been involved in the design and manufacture of sealants over the years and have also spent god knows how many hours applying them and, on occasion, removing them.

Best
WOPaving