Acorn Stains

[Kory 14]

Have any of you been able to get the purpleish black stains that acorns leave behind when crushed. I tried concrete cleaner, muratic, and degreaser non of it worked. any advice would be great.

[squirtgun 122]

Did you give some 12% SH a shot?We use it mixed 50/50 with water to remove tannin stains from leaves and pine needles.

[seymore 90]

I thought Oxalic removed most all stains from concrete?

[DustinC 64]

A pump up with 50/50 12% works for me.

[Barry M 73]

I downstream 12% and the stains disappear before I hit it with the SC. I use oxalic only for irrigation rust and it's sprayed on after surface cleaning and then rinsed.

[Patrick at HMSGA 14]

In Georgia, we get a LOT of leaf, berry, acorn, and other similiar stains left on concrete that will not come off with most cleaners or pressure.

Bleach gets almost almost all of them almost every time.

I keep a pistol grip bottle with 6% full strength Clorox. After I have cleaned a concrete area, go back with sprayer and spray stains. By the time I get back to rinse they are usually completely gone.

Almost kinda hate to tell the customer that they are so easy to remove.

[Barry M 73]

I keep a pistol grip bottle with 6% full strength Clorox. After I have cleaned a concrete area, go back with sprayer and spray stains. By the time I get back to rinse they are usually completely gone.

I usually downstream the whole drive with 12% and then clean, it also helps prevent stripping up the drive with the SC.

[Patrick at HMSGA 14]

I usually downstream the whole drive with 12% and then clean, it also helps prevent stripping up the drive with the SC.

I didn't say I cleaned drives, although I was referring to cleaning concrete.

Yeah, that works too. I do pre wet-too, but don't always use bleach, or enough of it to remove these kinds of stains. Neither Sodium or Potassium Hydroxide will totally remove berry and leaf stains, but bleach will.

My work is 99% commercial, and mold and mildew aren't what I am focused on cleaning off the concrete. I mostly clean restaurants, use hot water, and remove things like oil, grease, gum, tobacco spit, crayons, throw-up, etc. Bleach wouldn't help any of those appreciably. I clean off the other stuff, then go back to get leaf and berry stains if there are any.

I wish I could post a sign for customers to read -

"When you are finished with your chewing gum, cigarettes, and crayons, if you cannot dispose of them properly, will you please be so kind to swallow them?"

Haven't done any residential concrete in years. I do some wood cleaning and refinishing when people are willing to pay my prices for it. I think that I am pretty good at it, but definitely not cheap.

I didn't mean to mislead anyone, and I don't strip topcoat off concrete either, unless it is intentional.

[FCPWLLC 233]

I have found Soddium Hypochlorite to do better on these stains after the Surface cleaner. Kind of just spray down the whole area after the pressure cleaning and it brightens the concrete up and takes care of theose stains.

[Beth n Rod 1,279]

I thought Oxalic removed most all stains from concrete?

As I understand it.....

It will take out tannin stains, yes, but it will also etch concrete if you are not careful.

Beth :cup:

[Adrian 155]

I'm with you Michael.

SC the flat work first then spritz SH light rinse if any . roll up get paid move onto the next. A time or two I have used lithium Hydroxide (photo chem) on super stubborn stains. You have to babysit this stuff and not let dwell too long or it will alien blood itself to the core of the earth. Not recomended except for last resort in my book. But it lifts ,pine cone and needle , acorn, oil etc.

[PLD 14]

If the stain is ORGANIC, use bleach. If it is metallic, use acid.

[Kory 14]

Thanks guys I will try it.