Clean It Up

UK Floor Cleaning Forum => Hard Floor Cleaning Forum => Topic started by: Rob@Blast off on April 17, 2016, 11:19:54 pm

Title: Black spot on york stone flags.
Post by: Rob@Blast off on April 17, 2016, 11:19:54 pm
I'm really struggling with black spot on a York stone patio at the moment, we have tried numerous applications of hypo and it's not touching it, as a last ditch attempt on Friday we sprayed it with algoclear but I'm not confident that it's going to help, so any ideas on how to proceed, I will get some pics tomorrow.
Title: Re: Black spot on york stone flags.
Post by: Tadgh O Shea on April 18, 2016, 12:07:34 am
I'm really struggling with black spot on a York stone patio at the moment, we have tried numerous applications of hypo and it's not touching it, as a last ditch attempt on Friday we sprayed it with algoclear but I'm not confident that it's going to help, so any ideas on how to proceed, I will get some pics tomorrow.
Hi Rob, the dreaded black lichen spots on York stone indeed are a curse, the only tool i have found to remove them completely is to scrub them with stainless steel scouring pads which is a hand and knees job and i know that's not practical but the only way i ever found to completely remove them.
If i can share another method that i have never tried but maybe worth a shot if you are willing, and yes i will get put down quickly for this as most of the guys on this section know about my aversion to using sodium hydroxide based cleaning chemicals, but here goes anyway get some gel oven cleaner which is laced with sodium hydroxide and with a small paint brush dab each of the black lichen spots with the oven gel and allow it to dwell for 5 to 10 minutes, then afterwards see if your pressure washer with a turbo nozzle will rid the little blighters just a thought in case you think its worth a go.  Meant to say also Rob that gel oven cleaners it dose not matter which brand as they are all heavily laced with sodium hydroxide and will soften and breakdown heavy baked on carbon from ovens,grilles, after a dwell time of 1 to 2 hours, and because they are so aggressive can even cause chemical staining to stainless steel surfaces, so when it comes to using it on York stone you may have to play around with it as i can't say what kind of reaction you may encounter depending on the amount of dwell time required as i say its a shot maybe worth trying out. Tadgh
Title: Re: Black spot on york stone flags.
Post by: Kev Martin on April 18, 2016, 07:06:05 am
I'm really struggling with black spot on a York stone patio at the moment, we have tried numerous applications of hypo and it's not touching it, as a last ditch attempt on Friday we sprayed it with algoclear but I'm not confident that it's going to help, so any ideas on how to proceed, I will get some pics tomorrow.

Pre wet the stone, apply Miracle Heavy Duty Acidic Cleaner, Scrub it in using a Mono Rotary Machine fitted with an 80 Grit SIC Brush, add honing powder if necessary, scrub again, extract with a wet vac, rinse and extract again
Title: Re: Black spot on york stone flags.
Post by: David Deer on April 18, 2016, 11:23:34 pm
If you are really desperate you can call The Patio Black Spot Removal Company Ltd  (http://www.youtube.com/watch?v=P3tJ1ncuFD0)
I'm not sure what they specialise in though  ;D
Title: Re: Black spot on york stone flags.
Post by: Barry Poole on April 19, 2016, 08:39:06 am
Lol £44 for 2 litres
Title: Re: Black spot on york stone flags.
Post by: Rob@Blast off on April 21, 2016, 10:42:25 pm
Lol, popped back to the job yesterday and they have faded slightly but still there so will speak to the customer when they return and see if they want to pay for an extra days labour and have a go at it with a rotary.
Title: Re: Black spot on york stone flags.
Post by: Les on April 28, 2016, 08:25:58 am
Used the Bl;ack Spot Remover as mentioned above on Polished Sandstone Patio.....Really excellent product and great results....However, you do require a good covering of the solution and it is expensive....

I think the suppliers really should look into a Trade Discount  as the price will restrict my useage.

Les
Title: Re: Black spot on york stone flags.
Post by: Smurf on May 02, 2016, 12:47:29 am
Bit all over the top for and patio methinks  ???
Title: Re: Black spot on york stone flags.
Post by: Smurf on May 02, 2016, 01:11:51 am
Used the Bl;ack Spot Remover as mentioned above on Polished Sandstone Patio.....Really excellent product and great results....However, you do require a good covering of the solution and it is expensive....

I think the suppliers really should look into a Trade Discount  as the price will restrict my useage.

Les

I would be interested to see that product msds as can't find it on their site or shop either.
By the way it reacts on contact I would say it looks like a hypo based product to me.
Title: Re: Black spot on york stone flags.
Post by: Mike Halliday on May 02, 2016, 08:32:28 am
I though the same thing after watching the video, it's hypo probably with a bit of perfume. I'm amazed that someone can build a full business around removing black spots on patios