Bluestone stain woes - help! Pics attached

avenger_chicago

Gold Supporter
Jun 22, 2019
176
Chicago
We have bluestone around our pool and as part of a patio in the back of our house. We have a large maple tree. We came home from being away for a few days and noticed some large rust looking stains, distributed under the tree. I’m guessing these are bird droppings. Well, they have proven quite resilient to my attempts to remove!

I have attempted mild dish soap, vinegar, hydrogen peroxide, and another grease stain removal containing TSP among other proprietary ingredients.

I am at my wits end, however people are telling me just to watch and wait and let the sun oxidize the stains. I would like a faster result.

Any thoughts? Pics below.

Mark693D90BC-362E-469E-B523-E52764FE760D.jpegD00B7313-DAF3-42A1-B019-4EEB42BBC06A.jpegB0ED85B9-E41F-4791-8468-10B337074E52.jpeg0B86473A-E01E-4F72-9E14-CC1A429D389B.jpeg
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
17,368
Tucson, AZ
Can you purchase just straight TSP (trisodium phosphate) from the hardware store? HD in my area sell Savogren brand TSP. Get REAL tsp, not alternative or "green" or "eco friendly" TSP....it's NOT TSP. Then follow the instructions for cleaning concrete with a mixture of TSP and bleach. If TSP+bleach doesn't touch it, then there's not much else you can do without damaging the stone.
 
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avenger_chicago

Gold Supporter
Jun 22, 2019
176
Chicago
I picked some up but then decided against buying it. Yes I can try that. I’ll start in an inconspicuous location first. Someone at the hardware store also recommended bleach.

If nothing touches it I’m wondering if Mother Nature will work on it over time...
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
17,368
Tucson, AZ
I picked some up but then decided against buying it. Yes I can try that. I’ll start in an inconspicuous location first. Someone at the hardware store also recommended bleach.

If nothing touches it I’m wondering if Mother Nature will work on it over time...

TSP is great to have around a home, it is a versatile cleaner and can be used to clean everything form wood to concrete....except aluminum. Never use TSP anywhere near aluminum.

Mother nature will take her time and, in the mean time, her many critters will continue to use your deck as their personal toilet bowls....and then mother nature will laugh at you by sending some crazy storm down upon you that dumps 800 feet of snow and causes freeze damage to your deck....so fight back with TSP and bleach and thumb your nose at Mother Nature ... she's not worth waiting for ...
 

avenger_chicago

Gold Supporter
Jun 22, 2019
176
Chicago
TSP is great to have around a home, it is a versatile cleaner and can be used to clean everything form wood to concrete....except aluminum. Never use TSP anywhere near aluminum.

Mother nature will take her time and, in the mean time, her many critters will continue to use your deck as their personal toilet bowls....and then mother nature will laugh at you by sending some crazy storm down upon you that dumps 800 feet of snow and causes freeze damage to your deck....so fight back with TSP and bleach and thumb your nose at Mother Nature ... she's not worth waiting for ...
Thanks for making me chuckle. After spending so much money on our patios my first reaction was to cry.
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
17,368
Tucson, AZ
If the chemistry does not work, you could use a high-pressure power washer to try to mechanically remove the stains. It would be good to practice on a test piece of that bluestone material if you happen to have any extras around. That way you can adjust the spray pressure and nozzle type to optimize stain removal without "cutting" too much of the stone away.

Is it a large deck? Is there a possibility of sealing the stone after you get it clean? There are many high quality sealers out there (StoneTech is a good one) that could help to keep the stone from getting re-stained.
 

avenger_chicago

Gold Supporter
Jun 22, 2019
176
Chicago
If the chemistry does not work, you could use a high-pressure power washer to try to mechanically remove the stains. It would be good to practice on a test piece of that bluestone material if you happen to have any extras around. That way you can adjust the spray pressure and nozzle type to optimize stain removal without "cutting" too much of the stone away.

Is it a large deck? Is there a possibility of sealing the stone after you get it clean? There are many high quality sealers out there (StoneTech is a good one) that could help to keep the stone from getting re-stained.
We tried pressure washing to no avail. We do understand the stone is sensitive to power washing. The contractor actually probably power washed it with too much pressure and there are some small marks from that.

The deck is large, it basically takes up most of our backyard. If we get it clean I think we should strongly consider sealing it.
 
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avenger_chicago

Gold Supporter
Jun 22, 2019
176
Chicago
If the chemistry does not work, you could use a high-pressure power washer to try to mechanically remove the stains. It would be good to practice on a test piece of that bluestone material if you happen to have any extras around. That way you can adjust the spray pressure and nozzle type to optimize stain removal without "cutting" too much of the stone away.

Is it a large deck? Is there a possibility of sealing the stone after you get it clean? There are many high quality sealers out there (StoneTech is a good one) that could help to keep the stone from getting re-stained.
So, I tried bleach and TSP. Lightened it a bit but not enough to warrant doing the whole deck.
Our PB has been of no help.
If they don’t help address, may call a masonry expert.
Would muriatic acid work?
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
17,368
Tucson, AZ
So, I tried bleach and TSP. Lightened it a bit but not enough to warrant doing the whole deck.
Our PB has been of no help.
If they don’t help address, may call a masonry expert.
Would muriatic acid work?
I think it’s a time/elbow-grease thing. If the TSP/bleach solution worked to lighten it, then it will eventually work, you just need to invest a lot of sweat-equity in the project. You can adjust the TSP/bleach concentrations to make it stronger, you just want to be careful about it.

I would NOT use acid. Acid is going to severely etch the stone, roughen the surface and possibly weaken it. You can’t really control an acid wash and I’ve seen it applied haphazardly where it leaves all kinds of swirls and color defects. I think it’s a bad idea at best.

You could try taking a bunch of picture and then if you have a masonry supply store nearby (not HD or Lowe’s, but a true masonry supplier ... the business that sells stones to actual masons) you can show them and they might recommend a stronger cleaning product that’s safer.
 
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avenger_chicago

Gold Supporter
Jun 22, 2019
176
Chicago
I think it’s a time/elbow-grease thing. If the TSP/bleach solution worked to lighten it, then it will eventually work, you just need to invest a lot of sweat-equity in the project. You can adjust the TSP/bleach concentrations to make it stronger, you just want to be careful about it.

I would NOT use acid. Acid is going to severely etch the stone, roughen the surface and possibly weaken it. You can’t really control an acid wash and I’ve seen it applied haphazardly where it leaves all kinds of swirls and color defects. I think it’s a bad idea at best.

You could try taking a bunch of picture and then if you have a masonry supply store nearby (not HD or Lowe’s, but a true masonry supplier ... the business that sells stones to actual masons) you can show them and they might recommend a stronger cleaning product that’s safer.
Thanks! We may try a masonry store. Our PB just messaged me back stating the stone rep recommended an "alkaline cleaning solution" and didn't specify the exact product, but was going to get some to us.

We shall see...
 

Chrissykr

Well-known member
Jun 8, 2014
623
Rogers, AR
I would try Tide powder along with some Oxiclean Maxforce. Both in the laundry section I would make a paste with some bleach and rub it on and let it set for awhile. I use this stuff for everything with really good results.

Get the old fashion tide powder it has enzymes. No pods, green, eco or anything else.

excuse my messy background we are deep into fall decorating.
 

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avenger_chicago

Gold Supporter
Jun 22, 2019
176
Chicago
I would try Tide powder along with some Oxiclean Maxforce. Both in the laundry section I would make a paste with some bleach and rub it on and let it set for awhile. I use this stuff for everything with really good results.

Get the old fashion tide powder it has enzymes. No pods, green, eco or anything else.

excuse my messy background we are deep into fall decorating.
Thanks! I’ll add this to the list of chemicals to try!
 

avenger_chicago

Gold Supporter
Jun 22, 2019
176
Chicago
Nothing worked!

detergent
Hydrogen peroxide
Bleach
Vinegar
TSP
Tide
Oxyclean
Pressure wash with high pressure nozzle.

Any chance this will just “patina” over time? I can’t seal until it’s clean. And these stains are horrendous.

It must be some berry that the birds are eating at this point in the season because this is all red brown bird poop, not the usual white poop. Some of the spots are lightening which gives me some hope.
 
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JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
17,368
Tucson, AZ
It’ll age away with time. Surprising that none of cleaners penetrated enough. I will tell you this - bird droppings are highly acidic in nature and can have a pH as low as 3.5 as compared to mammal scat which is typically neutral pH (except when @Dirk makes his famous habanero/ ghost pepper chili .... then the local waste treatment plant needs to be alerted to have extra soda ash on hand to deal with the acidity coming down the line). At low pH and high “berry” content, my guess is the bird poop etched the stone a bit and penetrated pretty deep. This happened to an old car of mine - I left some bird poop on the hood too long before getting it washed and it damaged to clear coat right down to the paint.

You could perhaps test an acidic cleaner. Try mixing some cleaning vinegar (6% acetic acid) with peroxide (not OxiClean, get some of the 3% stuff at the drug store) and see if helps clear up a non-conspicuous spot.
 

JamesW

TFP Expert
Mar 2, 2011
21,092
Maybe get a product made specifically for stone.

There are many products available online or you can go to a local stone dealer to see what they recommend.

Maybe try a driveway and concrete cleaner product.

Maybe try a few different types of solvent to see if you can find one that works. The safety and availability of solvents vary. So, do your own research before considering solvents.
 

avenger_chicago

Gold Supporter
Jun 22, 2019
176
Chicago
Maybe get a product made specifically for stone.

There are many products available online or you can go to a local stone dealer to see what they recommend.

Maybe try a driveway and concrete cleaner product.

Maybe try a few different types of solvent to see if you can find one that works. The safety and availability of solvents vary. So, do your own research before considering solvents.
At this point my partner and I are calling a Mason expert as the PB hasn’t quite helped the way we would like. I might try a couple of other additional recommendations in the thread. What an exercise in frustration. Particularly because this was supposed to be our “stress-free” zone.

I guess it’s back to good old meditation! LOL.