Patina on concrete..

[Don L]

Happy INDEPENDENCE day!
Hello everyone,it's been awhile.
Busy is as busy does,ya know.
Anyhoo...
I've got a commercial customer that has patina(verdigris) that has dripped from roof flashing(copper)onto "relativly" new cement side walk.I am not sure how new yet.I believe that it has leeched into the sidewalk,who knew!
It is copper carbonate,I think.
I am relative newbie to the industry,so I am seeking guideance.
What would you recommend to remove it from the sidewalk?
It is a sensitive area,if possible I would ,of course,like to use a non corrosive..but simply don't know.
Any suggestions?
Thanks .Can't....find... spell .......check...sorry.

[Richard]

I've got a house with the same problem. Diedrich Technologies says there is now way to remove it. Yet I read that Saferestore might work ?????

[Don L]

Thank you ,Richard.
Anyone else?

[MMI Enterprises]

Two ways to remove...
1. Mechanical grinding/sanding using either hand stone blocks or diamond tipped cup on electric grinders. Easy does it as you can leave marks, expose aggregate, and of course loose whatever finish maybe present. (not likely an issue since the stain went into the crete)
2. Chemical leaching of the mineral deposit via using diluted acid. Choices are oxalic, phosphoric, or hydrochloric (muriatic) with the muriatic being my favorite. Damage/etching of the concrete will occur at some level but in my opinion is better option to grinding. Quik dose it about 8:1 with scrub brush to where ya get some bubbling or stronger if need be and you can risk more loss of concrete. Neutralize immediatly after with tsp or baking soda, or ammonia or most any alkaline cleaner as soon as the stain breaks down. If need be apply oxalic after if the hydrochloric discolors the crete. Worst case scenario you can stain the area with concrete colored stain. ..pm me if you need any further help.

[Don L]

Hey Kevin
Thanks for the reply, but I don't know how to pm.
I know ,stop laughing.

[Lightning Gene]

Originally Posted by Don L

Happy INDEPENDENCE day!
Hello everyone,it's been awhile.
Busy is as busy does,ya know.
Anyhoo...
I've got a commercial customer that has patina(verdigris) that has dripped from roof flashing(copper)onto "relativly" new cement side walk.I am not sure how new yet.I believe that it has leeched into the sidewalk,who knew!
It is copper carbonate,I think.
I am relative newbie to the industry,so I am seeking guideance.
What would you recommend to remove it from the sidewalk?
It is a sensitive area,if possible I would ,of course,like to use a non corrosive..but simply don't know.
Any suggestions?
Thanks .Can't....find... spell .......check...sorry.

Wet the concrete down and apply straight safe restore to it and let it dwell 30 minutes but don't let it dry....might take more than 1 application

[MMI Enterprises]

In followup.. Don opted to use the CLR due to sensitive location and said it rocked.