Can you describe your process
Tannins are the collective name given to the acidic chemicals held in solution in the liquid sap, they are still present in dry oak as they are left behind when the water evaporates. They get their name from the leather tanning industry which used to use oak , and oak bark to tan leather.
I’ve had the same problem with Black Walnut. It could not be removed from a deck I cleaned so the client painted the deck. I believe that their acidic nature allows them to penetrate the substrate in a way a mold/mildew/algae could not, making it resistant to cleaning and bleaching. I’ll be on the look out for this in the future so I can advise clients about it. Hopefully some of the folks with more experience than me can offer some advice on this.
What was your feel dwell time with the sh?
Very helpful, thank you
So I started with the bleach on one spot, just poured straight on. Same with the chlorine which was %10.5 but on a different spot. I let them both sit for five mins with no change. I pressure washed them, nothing. I reapplies and did the same for 10 mins. No change. I mixed tsp water and 10.5 sh and let it dwell about 20 mins then again no change even with close up washing. The degreaser was on a stain the entire time with no change.
did you use hot water by chance or cold?
You didn’t use an acid on it did you? Some threads on here suggest trying oxalic (test spot first of course).
No, not yet. I may try that, thanks!
I don’t have any advice for your specific scenario vut I just wanted to let you know that if youre buying sh (chlorine) and bleach youre wasting your $. Whats commonly sold as bleach is just a watered down sh.
Did you try a surface cleaner? How about a brush. Sh needs to dwell longer than 5 mins wet the concrete apply 12.5 come back in a hour
What?? Lol
So 10% sh in pool essentials is just watered down SH? Isn’t the highest percentage you can buy 12.5? Don’t seem watered down if it’s the 2nd highest concentration available.
I assuming he is talking about the bleach you do your laundry with. Maybe
Thevlvstuff sold for pools is commonly sold as chlorine. The only time I ever see anything labeled as bleach is when you’re buying “bleach” for laundry. But its all just sh was my point.
So I used bleach because a customer gave it to me as they tried it for a different job and didn’t use much so I said I’d take it. I normally use 10.5 sh. Either way I’m more focused on the stain. I didn’t think to let it dwell that long. The longer it sat the more it dried up. By 15 mins it was about dry. The sun was beaming. I do use a surface cleaner but I took it off and used a nozzle for these stains. I did use a brush when I used the tsp. I appreciate the tip though. Maybe I can try to let my 10.5 sit for a hour and go back. Worth a shot.
Don’t trust what the customer gave you it could be years old. Homeowners don’t go through this stuff like we do and know nothing about shelf life of this stuff. If it’s hot keep it wet at all times, this stuff works if it’s wet.
No put.12.5 on it early in the morning keep it damp if sh dries its done dampen the concrete will help it not dry out maybe we can get @gbattle to chime in
If it’s organic SH should take care of it. If the sun was shining and, you sprayed a little sh on warm concrete, it’s going to dry up before it can work. As @Firefighter4hire said go first thing in the morning when it’s cool out. I’d probably start off with about a 6% mix, soak it until it almost puddles, and a spray again if needed. It won’t hurt to go straight SH though. You probably just didn’t soak it down enough. On stains like that you can’t just mist a little bit of SH and hope it works and especially if the concrete is hot.
Yeah I didn’t even use the sprayer. I poured it straight on. I will def try early in the morning. I’ll keep y’all posted. Fingers crossed
