Rust stain remover for house paint?

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Sclass
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Joined: Tue Jul 10, 2012 5:15 pm
Location: Orange County, CA

Rust stain remover for house paint?

Post by Sclass » Mon Sep 09, 2019 8:14 pm

I have some rust stains from water dripping over rusty nails along an exterior wall at my place. I’d like to clean off the rust stains and keep the paint on the stucco.

I’ve tried vinegar, dish detergent and backing soda with a brush. Vinegar worked best but it didn’t get it totally clean. The iron rust is really stubborn. I saw this stuff called Whink but I looked up it’s MSDS and it contains hydroflouric acid. It was pretty scary, the sheet said it can damage bone and tissue...yeah no kidding it’s HF! I actually saw a hacker once use this stuff to dissolve the upper layers of a secure microchip to get access to internal data lines. He literally used a bottle he got at the hardware store and said it was HF. I didn’t believe him but now I kind of recognize the brown bottle. Long story short, it works but I don’t want that stuff near me.

Anyone got any tips for mild cleansers that will take this off? It looks like I’ll need an acid. Vinegar may be too weak.

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jennypenny
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Location: Stepford USA

Re: Rust stain remover for house paint?

Post by jennypenny » Tue Sep 10, 2019 7:32 am

I've never needed to try it, but my grandmother said to rub rust stains with a potato dipped in salt (obviously cut the potato in half first), leave it on there a while, and then rinse with lemon juice and scrub with the rind.

I have no idea if it works or why it would work. At least you'd have the makings of potato salad if it didn't. :D

Sclass
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Joined: Tue Jul 10, 2012 5:15 pm
Location: Orange County, CA

Re: Rust stain remover for house paint?

Post by Sclass » Tue Sep 10, 2019 7:59 am

Thanks JP. I’ll give it a try.

IlliniDave
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Re: Rust stain remover for house paint?

Post by IlliniDave » Wed Sep 11, 2019 3:16 pm

Can't say for house paint, but CLR is rated very safe and is fairly effective (less so than Lime-A-Way). I've used both at my cabin to get rid of rust stains due to high iron content in the well water.

https://www.ewg.org/guides/subcategorie ... ainRemover

Sclass
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Location: Orange County, CA

Re: Rust stain remover for house paint?

Post by Sclass » Thu Sep 12, 2019 7:38 am

Tried the potato lemon salt. Didn’t work. I got some out but I think that was mostly from the scrubbing action removing the top layer of paint. Smells good outside my window now.

Apparently my wife has some CLR she got for the toilet. She told me after she called a painting contractor to just paint over the wall. I think I’ll dig through the cabinet of bottles and try it just for academic curiosity.

Thanks for the tips.

Sclass
Posts: 1633
Joined: Tue Jul 10, 2012 5:15 pm
Location: Orange County, CA

Re: Rust stain remover for house paint?

Post by Sclass » Thu Sep 12, 2019 3:28 pm

Sclass wrote:
Thu Sep 12, 2019 7:38 am
Tried the potato lemon salt. Didn’t work. I got some out but I think that was mostly from the scrubbing action removing the top layer of paint. Smells good outside my window now.

Apparently my wife has some CLR she got for the toilet. She told me after she called a painting contractor to just paint over the wall. I think I’ll dig through the cabinet of bottles and try it just for academic curiosity.

Thanks for the tips.
Ahh, didn’t have clr. It turned out to be this Lysol product that promised to remove rust and lime. The active ingredient was 10% hydrochloric acid. It worked better than the lemon or vinegar. Things are lighter but there is still a rusty hue left. I think it’s time to move on with the paint.

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