What went wrong?

[Kurt 14]

The good news is that this is my house and getting ready to be painted. However, I'd appreciate some input here. Used oxalic to remove some iron stains from the painted stucco. See where it lightened the paint?

I mixed according to directions and rinsed well immediately after watching the stains vanish.

Think the mix was too strong? Should I have used something else?

Boy, I feel goofy.

[Jeff 232]

I've done over a thousand or more homes with Ox and at least a couple hundred were dryvit/stucco and this has happened to me also, only once. I've tried to figure why and cant really explain it. I figure its something in the pigment of the coating. I now do a weaker mix of ox on stucco and then will do a couple applications. it also happened twice on some older painted trim

I'd like to know why this happened also

[Neil_Asheville 114]

Kurt. I'm dealing with a house right now, two weeks after washing, that I'm playing the blend the ox cleaned vinyl into the old vinyl game. Luckily she's in my neighborhood and on my way to/from days jobs. I did TOO good of a job cleaning this one. Instead of simply cleaning the house and not trying to be hero and bust out the Ox, I'd be done and paid. HO had some new random vinyl lower/bottom courses put in and the manufacturer confirmed it was the same color when originally installed. Before cleaning it looked and entirely different shade. I now realize how dirty and polluted 4-5 year old vinyl can get. I also now know how strong OX can be.

Ox has restored this old dingy vinyl back to factory new. So much I'm thinking of this as an entire house upsell at big $$$. Problem is now with this house I'm trying to blend in from very clean on the bottom to clean but dingy as you move up the house.

/neil

[Howard 50]

Kurt. I'm dealing with a house right now, two weeks after washing, that I'm playing the blend the ox cleaned vinyl into the old vinyl game. Luckily she's in my neighborhood and on my way to/from days jobs. I did TOO good of a job cleaning this one. Instead of simply cleaning the house and not trying to be hero and bust out the Ox, I'd be done and paid. HO had some new random vinyl lower/bottom courses put in and the manufacturer confirmed it was the same color when originally installed. Before cleaning it looked and entirely different shade. I now realize how dirty and polluted 4-5 year old vinyl can get. I also now know how strong OX can be.

Ox has restored this old dingy vinyl back to factory new. So much I'm thinking of this as an entire house upsell at big $$$. Problem is now with this house I'm trying to blend in from very clean on the bottom to clean but dingy as you move up the house.

/neil

So let me get this straight. "Ox isn't just for rust stains anymore"? Your using Ox in your rinse water on vinyl? Tell me more, what about windows? Not a problem etching the glass? Apply with x-jet or downstream?

Thanks

[Beth n Rod 1,279]

Two things are happening here.

1- The minerals are getting lodged into the surface through leaching and precipitation as weather and new water exposure allows. This is decomposition.

2- Most paints used on stucco or in this case E.I.F.S. is based in the range of acidity to be able to adhere to this type of surface. Therefore, cementatious paints can be damaged by acids as a result. But it requires a strong concentration or lengthy dwell time to do so.

A possible 3rd is that someone else before you has treated this area and you are the messenger of that previous cleanings effect, and in combination with additional mineral decomposition and UV degradation in between times, the result is what you have shown in the pics above.

Rod!~

Ps, is it me or does it appear that the area has been repaired some time in the past? The continuity of the E.F.I.S. does not look the same as the area above it.

[John Orr 206]

Two things are happening here.

1- The minerals are getting lodged into the surface through leaching and precipitation as weather and new water exposure allows. This is decomposition.

2- Most paints used on stucco or in this case E.I.F.S. is based in the range of acidity to be able to adhere to this type of surface. Therefore, cementatious paints can be damaged by acids as a result. But it requires a strong concentration or lengthy dwell time to do so.

A possible 3rd is that someone else before you has treated this area and you are the messenger of that previous cleanings effect, and in combination with additional mineral decomposition and UV degradation in between times, the result is what you have shown in the pics above.

Rod!~

Ps, is it me or does it appear that the area has been repaired some time in the past? The continuity of the E.F.I.S. does not look the same as the area above it.

I vote for number one. I would try (test in an inconspicuous area) SureKleen 600 and/or SafeRestore. If the surface bubbles, it may work. What's the worst that could happen? Acid Burn? ;) (See previous post to get understand the humor in that statement.)

[PressurePros 248]

Its a very good idea to prewet any masony surface before you apply acid.

[Kurt 14]

Thanks for the response guys. There have been no repairs to the area although some is needed where the weed eater line keeps hitting the house.

The ox worked great on the pool deck to remove the iron stains but I was seriously bummed about the house. I even did a small test spot but I guess I should have waited longer to see the final results. I realize that hind sight is 20/20.

As I'm sure you're all aware, the label on the ox reads, "Not to be used on paint, stains or brick containing iron oxide pigments. I wonder if this could have been the cause of the fading.

How does a person determine if a paint or stain contains iron oxide pigments without knowledge of what brand/type etc paint was applied?

[Washaway 64]

Kurt,

Before you start using oxalic for rust removal try going to the good old Lowe's/Home Depot and buy yourself a gallon of Rust Aide. They claim it to be non-acid based and it works without any problems.

I like it better than anything else I've ever tried and need to find out how to get larger quantities, maybe from manufacturer.

[Kurt 14]

I have some Rust Aide. It says, "Contains Oxalic acid". I simply wanted to try the powdered form. What I actually ended up using was Snow Cap.

[Washaway 64]

Hm...I must have it confused with something else.

[scratching head vigorously]

[Ron Musgraves 240]

I've done over a thousand or more homes with Ox and at least a couple hundred were dryvit/stucco and this has happened to me also, only once. I've tried to figure why and cant really explain it. I figure its something in the pigment of the coating. I now do a weaker mix of ox on stucco and then will do a couple applications. it also happened twice on some older painted trim

I'd like to know why this happened also

Jeff that’s the correct answer, it’s reacting with the water or something on the surface. (Paint brand) if it happened lower on the house over spray from stem wall sealer. Alos may not have penitrated the sealer where wall was over sprayed.

If past experience I have found rather than go at things aggressive it best to start slow and apply more if necessary.

Often we get to aggressive and cause permanent damage that cannot be reversed.

Funny this thread is exactly what I was trying too saying in a thread earlier.

The chemical may be incorrect for the job depending on the material and type of paint?

Most often it just goes back to the aggressive chemicals. Reduce chemicals strength and start slower; often you can achieve the correct strength needed. With practice in time you will get better at making the correct formulas.

Often consumer chemicals are weaker to start with, when you start using industrial or pro chemicals you need to make adjustments. (Most use home made brews) or they modify products mixed by smaller chemical companies.

Some manufactures warn against adjusting due to water minerals actually changing the composition of the chemical. (Very rare but read the labels)

[Ron Musgraves 240]

auto sprinklers could have change the make up of the paint also.

[WEW 14]

auto sprinklers could have change the make up of the paint also.

I think Ron has it. It was there already, you just took away what was covering it.

ISYHTRAH

[SQUEEKY 14]

hey Kurt glad it was your house?! but what would the liability have been if it were a cust. home?

was this a result of your workmanship or defective materials applied by another contractor? do you have anything contractually to protect you if you are not at fault?

luckily this thread has nailed down the possible reasons for this. what methods do you all preform for testing areas??

THANKS

[SQUEEKY 14]

???????

[Kurt 14]

"Seems "as though the problem was my paint. I've used the same solution/ratio and method of application on 3 different stucco homes(family) since I did my own and have had no issues at all.

However, out in the real world,I do believe that it is best to mix a little weak and re apply if necessary.

I washed my brother's roof yesterday and could not believe how good his 5 year old paint looked on his house. Mine is also 5 years old and looks faded and dull. His house is very shaded. Mine is not and it gets blasted by the florida sun.

Eh...This is why we practice, test things, study and learn before hitting the streets and making a mess of things.

No sense in rushing out, throwing around chems screwing up jobs and in the process, muddying up the waters for all PW's in general. This is the approach I'm taking anyway. Better safe than sorry.