natural slate stone patio laid , grout haze marks on stone

[Mart the landscaper]

Laid a natural stone slate patio. Used projoint max expoxy paving grout used it for nearly 2 years. Yet after 6 hours sudden change in weather so went and covered and sheeted over as advised with water proof sheet. Came next morning removed and now got milky epoxy residue haze on stones. Any ideas as i rang manufacturers whos techincal said use white vinegar yeah i know i tried a sample but did nothing on the area although i was reluctant any suggestions job was only done saturday morning want to react quick

 

[J K Tiling Cornwall]

I'd get a nylon brush attachment for a hand drill, will try to attach a pic or link... if epoxy maybe use acetone? Does evaporate pretty quick though. Test on a off cut or area out of sight first. Shouldn't harm the slate.

[automerge]1592426119[/automerge]
... pretty certain toolstation stock them

 

[Mart the landscaper]

I'd get a nylon brush attachment for a hand drill, will try to attach a pic or link... if epoxy maybe use acetone? Does evaporate pretty quick though. Test on a off cut or area out of sight first. Shouldn't harm the slate. View attachment 112748
[automerge]1592426119[/automerge]
... pretty certain toolstation stock them

I will try anything any help appreciated will acetone be alright on natural slate stone you think ?

 

[Dave]

It doesn’t look like grout haze to me.
Is there a salt formation on the surface, does it cone off onto your fingers when you rub it. ?

 

[Mart the landscaper]

It doesn’t look like grout haze to me.
Is there a salt formation on the surface, does it cone off onto your fingers when you rub it. ?

We used the projoint max epoxy grout you can use in light rain it said weather forcast was fine so did it 6 hrs later on the evening weather suddenly changed unexpected and not indicated it advised in heavy rain to cover up so we completely covered at 10pm and 9 am nect morning removed covers. The manufacturer said yesterday its known as white blooming which is rare but dont seem to care said it could be from moisture they really dont know and have suggested to try LTP solvex as vinegar hasnt worked they dont seem to know and are not returning our calls all instructions were followed correctly i will check today about the salt question and post back thank you. Tried ecoprotec yesterday thats done nothing either was also told to try that. Rather concerned at the min.

 

[Mart the landscaper]

I will try anything any help appreciated will acetone be alright on natural slate stone you think ?

Apologies its natural indian stone not slate
[automerge]1592480830[/automerge]

It doesn’t look like grout haze to me.
Is there a salt formation on the surface, does it cone off onto your fingers when you rub it. ?

Also my mistake its natural indian stone not slate
[automerge]1592480895[/automerge]

I'd get a nylon brush attachment for a hand drill, will try to attach a pic or link... if epoxy maybe use acetone? Does evaporate pretty quick though. Test on a off cut or area out of sight first. Shouldn't harm the slate. View attachment 112748
[automerge]1592426119[/automerge]
... pretty certain toolstation stock them

Apologies brush great idea doing that the stone is not slate its natural indian stone

 

[Dave]

We used the projoint max epoxy grout you can use in light rain it said weather forcast was fine so did it 6 hrs later on the evening weather suddenly changed unexpected and not indicated it advised in heavy rain to cover up so we completely covered at 10pm and 9 am nect morning removed covers. The manufacturer said yesterday its known as white blooming which is rare but dont seem to care said it could be from moisture they really dont know and have suggested to try LTP solvex as vinegar hasnt worked they dont seem to know and are not returning our calls all instructions were followed correctly i will check today about the salt question and post back thank you. Tried ecoprotec yesterday thats done nothing either was also told to try that. Rather concerned at the min.

Blooming will happen if water is in the stone and sealing was carried out before fully dry.

 

[Mart the landscaper]

Blooming will happen if water is in the stone and sealing was carried out before fully dry.

Any ideas at all the stone seemed all dry

 

[Dave]

Any ideas at all the stone seemed all dry

How long after laying and cleaning did you seal it

 

[Mart the landscaper]

How long after laying and cleaning did you seal it

Laying was finished around 4 days prior to sealing as we then installed a fence after that