Rust on Stucco and Window

I’ve have good luck with oxalic on vinyl but never tackled anything this bad or on stucco. Would you guys go ahead and get F9?

Nah. I’d go with OA. Should clean up just fine.

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Is OA safe on the aluminum windows like these?

Now that I have no clue. My inclination is to say probably not but you can always do a test area in a corner to see. Remember to keep the area wet and limit streaking as much as possible. Once the color is gone then rinse very well.

I’m going to say the rust may look worse than whatever the oa is going to do to the frame.

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I’ve never had issues with oxalic and aluminum. I’ve even used it to remove rust on old aluminum siding and didn’t hurt a thing. For the amount of time it will be on there I wouldn’t be worried. Now the F9 Barc I’m not so sure. It’s a stronger acid.

Ox isnt going to hurt the window frame. But I would either apply it with a brush or even better brush on some works toilet bowl cleaner I bet it will work

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Ok thanks. Planning on mixing 1 cup per gallon and applying with pump up sprayer then agitating with brush. Then reapply until stain is gone.

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Oxalic is worth a shot. I’d maybe even go stronger if it’ll dissolve. I doubt you’ll get much more than 10oz/gallon though. It’s going to take quite a few applications if it even removes it all. Be careful scrubbing too much on the aluminum. It looks new enough it shouldn’t hurt it though. You just have to watch out for the older oxidized aluminum. You might end up needing the F9 Barc and especially at the bottom. It just depends on how long the rust has been there.

Well I’m now sold on Oxalic Acid. Had this job today and the oxalic really did well. Took me about 20 min of applying and brushing but it all came off. Mixed 2 cups of oxalic to a little over a gallon of water. Kept wet and scrubbed with soft bristle brush until rust was gone then rinsed.


Boom! Headshot! Looks great, thats one to show perspective clients for sure.


Nice work! Sorry wrong dude.
Nice work @colbydent11

Results actually surprised me. I figured there would still be light shadowing. Glad I didn’t buy the F9.

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Looks great. Thanks for the update.

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Awesome job! I too love seing these after pics!