[Tom R]

Buddy of mine is starting a painting/powerwashing business. A customer wants him to powerwash his concrete driveway to wash of the green staining running off from a copper roof. Anyone know what will work? Thanks.

 

[Humble Abode]

What about an acid wash?

 

[Mike Finley]

I have heard of using Sure Klean's ferrous stain remover product to get rid of copper on brick and concrete. I don't think you need to powerwash it, just scrub it with a brush I believe. They might even have a specific copper stain removing product now.

(Damn, I hope I am not violating any codes by saying "I have heard" or "I believe") lol

 

[wasdifferent]

What about an acid wash?

Yup, you're right. Muriatic acid, it's diluted hydrochloric acid, be careful.

www.epa.gov/ttn/atw/hlthef/hydrochl.html

(Hope is not a method.)

 

[Tom R]

Thanks, guys, - - and thanks for the link, Mike S.

Mike F., - - thanks, - - he just got a brand new, shiny, expensive power washer, - - so I think he's kinda' lookin' for an excuse to use it

 

[wasdifferent]

You're welcome Tom, I'm glad I could help. I didn't pay as much attention in chemistry class as I should have, and I have had to re-learn much of it on my own. I'm glad that I did, it has given me a big edge, and saved me much time and money.

For anyone who is interested in chemistry, this is the best site that I have ever seen:
www.webelements.com

It got 65 million page reviews in 2004.

Best regards,

 

[Tom R]

Wow, - - cool site. That one goes right to my 'favorites'.

 

[wasdifferent]

Glad you like it, there's a tremendous amount of information there.
Best wishes,

 

[S.W.C]

Yup, you're right. Muriatic acid, it's diluted hydrochloric acid, be careful.

Yep, it'll clean concrete very well.

Be careful is right, it's deluted hydrochloric acid, but you'll still have to delute it even more with water.

About 20% muriatic acid to 80% water(about 1/4 gallon acid to six gallons of water), if you put it on straight you won't have any concrete left, you won't have a happy customer either.

And pour the acid into the water, not the other way around.

Fill a large bucket close to full with water, then add the acid, wear rubber gloves, safety goggles, and old clothes.

Even deluted the stuff will eat holes in your clothes, not when it gets on them, but after you wash them, they'll have holes in them anywhere you got the acid on them.