Oxalic acid on paint

[TammyN]

I'd be nervous about using oxalic acid or anything acidic on red, brown or orange paint that's weathered or is fragile. Those colors usually have red oxide pigment, which is iron(II)oxide. Rust is a form of iron(II)oxide so it seems like anything that chelates or sequesters rust could do the same with exposed paint pigment. That might be what happened to the part in the photo that turned pink-ish.

 

[Arababindigo01]

Been fooling around with Oxalic acid, aka wood bleach. I cleaned up some rusty Schwinn S2 rims to amazing condition. I wish would have taken some before shots. Anyway, for kicks I took a Schwinn frame with a rusty white front end and soaked it overnight. Here are the before and after pics-

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Wow! That worked great! My only concern is paint loss for older bikes. I have a 1939 schwinn I would like to use oxalic acid on, but am afraid paint will come off. Thoughts?

 

[New Mexico Brant]

Wow! That worked great! My only concern is paint loss for older bikes. I have a 1939 schwinn I would like to use oxalic acid on, but am afraid paint will come off. Thoughts?

Any paint loss will only be minor; that will be at places that paint is already loose and the rust is stabilizing it.

 

[tanksalot]

This is oxalic acid Elgin Orile progress . I didn’t even know what color this bike was until I removed the badge ! When I saw it was grey I decided to try to see if it could be saved . I still have more detailing to do but I’m happy with the result so far .

 

[catfish]

This is oxalic acid Elgin Orile progress . I didn’t even know what color this bike was until I removed the badge ! When I saw it was grey I decided to try to see if it could be saved . I still have more detailing to do but I’m happy with the result so far .

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Nice work.