# bluestone staining problem



## placid designs (Jul 15, 2013)

Hi,

Recently, completed a bluestone patio and used a polymeric stone dust (gator dust) in the joints. First time using this product. Over a few days the stones began to stain from the joints inward - about an inch or two. The stain starts as a whitening or bleaching and darkens as it moves inward on the stone before returning to the natural stone color. I've seen it referred to as "picture framing". Can't help but believe this is from the gator dust.

Base is compacted processed gravel, with about an inch of screeded stone dust below the bluestone. Tried a few products to remove it (in small test areas) 600, acid bath...thinking perhaps residual mortar haze - no luck. I've been told this is common with gator dust?! Been told to let it dry out - it will dissipate over time. Also been told the only thing that will get the stains out is a high temp pressure wash - which will also blast out the gator dust.

Never seen this before! Seems to be getting worse with time. Any ideas?

Thanks


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## Captainsls (Nov 8, 2007)

This is most likely the gator dust in conjunction with the inability to perfectly clean the fines/dust from the surface before applying a water mist to activate the gatordust. I have dealt with this multiple times with natural cleft bluestone and I used to factor in a couple cans of efflo-cleaner into every patio: http://www.sepulveda2.com/catalog_sepulveda/show_product_info.php?product=535

Ive since switched to a 'dustless' polymer sand and dont experience the salt haze issues like with gatordust. Waiting for mother nature to 'weather' away the haze WILL work, but it will take 4 months+ FYI. Sadly...this is common with gatordust, it contains too many fines for a natural stone. The Techni-Seal wont 100% remove the haze, but it will certainly help. Best product for this issue that I have found to date. Good luck!


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## 2low4nh (Dec 12, 2010)

get an efflorescence cleaner. paveprep or similar and a scrub brush. make sure when you use the product you keep it low in the joint and blow off the dust. it happens a lot.


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## placid designs (Jul 15, 2013)

Thanks a million for your response. Not sure it's only a mortar haze though - I did a quick acid rinse which removed most haze - maybe missed some - but staining remains. Interesting point about the dust in the polymers - spreading from the joints into the stone. That seems to describe the problem - so another cleaning may help?!

I'm trying to figure out how to show you a photo - think it's attached attached. I appreciate your advice.


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