Surface rust removal

[Twisted Root]

Hey all, my '58 Spitfire has been in the carport for too long. There's light surface rust on the frame (on the paint). What's the best way to remove this without putting the remaining paint in jeopardy? And once it's clean, what can I coat it with (car wax?) to keep it from re-rusting?

 

[Couch tater]

Post a photo if you can, knocking down rust can depend on a few factors such as how bad it is, paint color, if the paint is original.

 

[Indyjps]

Theres oxalic acid, or citric acid, or vinegar bath for the whole frame.

Ive had luck just soaking a rag in vinegar, wrapping the area that needs help (bottom bracket) and keeping the rag wet. Dribble on more vinegar every few hours. Works well for spot treatment. Area needs to be grease free.

Good coat of wax keeps it protected, or boiled linseed oil, though I prefer danish oil they work the same.

 

[Twisted Root]

jeez...6 months ago...just now getting back to this. I like the paper-towl idea. Maybe I'll wrap in plastic wrap too, to keep it from evaporating too fast...it's really dry here.

 

[Twisted Root]

Well that went poorly, to say the least.
The paint job is/was red and white. Over time the red had oxidized to that rust-primer color. Pretty cool patina. The white had turned warm/white/yellow/beige...also fine.
What I was trying to do was to remove the more-recent rust on the white areas that made it look orange.
But, to my dismay, the vinegar (cleaning strength from Home Depot) not only didn't do much to improve the white (maybe some improvement)...but worse, it took A LOT of the red paint right off the frame. I now have large bare metal patches where I used to have cool old red paint.
I made my bike look worse!
BEWARE this technique!
....!

 

[MattiThundrrr]

Cleaning strength vinegar is really really strong. That sucks.

 

[Captain Awesome]

Cleaning strength vinegar is really really strong

This ^

I'm pretty sure the intent for the light rust treatment was just standard vinegar. Not cleaning strength. I too have had good luck with regular old kitchen vinegar on treating painted surfaces. Although on many older bikes red is relatively susceptible to bleed simply because many of those red pigments are derived with iron oxide. Plus the UV factor of red is always working against you

Red paint reflects red light.
It therefore absorbs blue, green, UV etc that have greater energy and cause more "bleaching" of the pigments in the paint