[Tom-01]

Hi guys

I have tried hypo on some black spot and it doesn't get rid of it completely. I have a large-ish job to do (about 180m2) and she said she has found this product which she has been told removes black spot: https://www.silverlandstone.co.uk/products/universeal-new-clean-60

Should a strong mix of hypo remove black spot? She said she is happy to buy that product and we apply it and clean. I think I'm inclined to go down this route so the onus is on her if the black spot doesn't disappear completely.

Thanks
Tom

[Mike Halliday]

That removes grime with no aggatation, it’s a hypo mixed with something else, get a data sheet and look at  the ingredients, I bet it’s only a weak mix of hypo as well, not the full14% we can get.

Who told her it removes black spot? Her hairdresser? The customer is not the expert we are, if they have to tell us what to use then they might as well do it themselves

[Smudger]

Mike - Hypo will do it - very bad black spot will require full strength though

have you pressure washed the area ? - if so can the surface take a turbo nozzle - I've found that bad black spot needs to be hit hard with a turbo  to "crack" the outer surface then hypo will will dissolve the rest

may need 2 goes

Darran

[Tom-01]

Mike and Darran, thanks for your replies.

She phoned the stone company herself and they said it would get rid of it. I called them and it is a hypo based product. My thought of letting her get it means the responsibility is on her.

I hear what you're saying Mike, but tbh I haven't got time for the messing about. I think I might tell her to get her gardener to do it!

[SB Cleaning]

Mike - Hypo will do it - very bad black spot will require full strength though

have you pressure washed the area ? - if so can the surface take a turbo nozzle - I've found that bad black spot needs to be hit hard with a turbo  to "crack" the outer surface then hypo will will dissolve the rest

may need 2 goes

Darran

I agree

Full strength hypo give it a bit of agitation with a broom leave for 30-45 mins...may need to do it 2 to 3 times