What happened?

[Tronman 14]

I was called out to a ladies house that had a stain on her drive. When I got there I found out that another guy had tried to get the stain out but could not. I used a 12:1 concrete cleaner soln from Northern and deck brushed it. Nothing. The drive was concrete but not all smooth. It had a border of smooth concrete but the inside of each panel was rough in one direction. It looked very pourous. I washed down the drive and set up my pressure washer. I poured a more concentrated soln. on teh stains, scrubed and then hit it with a 45 degree at 2.5 gpm 280 psi. As soon as I started to move the chemical I noticed that wherever the chemical was - was now orange. The more I looked at the rest of the drive the more i noticed that every little scratch went through the top layer of the concrete and exposed the orange concrete below. It appears as though the top layer of the concrete was just a very thin layer of white. This is a new subdivision and she is one of four that have moved in on her street. Her homeowners association was on her case to get the stain removed. Now they are going to be going crazy over these larger orange stains.

Is there a way to repair this - new concrete layer, solid color spray sealer...

[Tronman 14]

The pics are at ***. I could not upload here???http://www.pressurewashinginstitute.com/board/upload/showthread.php?p=39691#post39691

[TNTPW 14]

Is that a red mortar taht soaked really good into the cement.

[Don Phelps 85]

Looks like the aftermath of a sniper's scope on an insurgent's head to me!

:lgbugeyes

[Tronman 14]

I think it was very poor quality concrete. Every scrape made previously by the customer went down to an orange colored substrate. It was almost as if the white concrete surface was painted on. Once the chemical and PW hit it there was nothing left of the surface color. With such a low psi it should not have damaged the surface. My only concern was the concrete cleaner from Northern.

[Beth n Rod 1,279]

I looks like a radiator leak and the rust in the fluid turned the cement orange.

Try a test spot using acid to clean (20:1) and see if it either lightens the spot or removes it where you have applied the acid.

This will give you a better idea of what will be the end result.

Just do a small spot though (1"x1") in the case the cement paste is not very thinck and also to avoid etching a large area.

Rod~

[Tronman 14]

This is the result after using the concrete cleaner from Northern at 12:1, then full strength. I think the cleaner went right past the thin surface of the concrete in less than 30 seconds. Now I need to figure out if it can be fixed.

[CCPC 26]

what is the base ingredient in the concrete cleaner? Did you let it dry on the surface? I've created a few stains that look just like that when I accidently drip some of my purple power degreaser on the concrete and forget to rinse it. Once it drys there, it leaves an orange/brownish stain that can't seem to be removed.

[Mike Williamson 198]

This is the result after using the concrete cleaner from Northern at 12:1, then full strength. I think the cleaner went right past the thin surface of the concrete in less than 30 seconds. Now I need to figure out if it can be fixed.

If it were me, I'd listen to Ron M....I think the guy is pretty qualified in the area of flatwork....Give him a call.