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I have a small spot of rust on the bottom side of my steel frame's top tube (Columbus Niobium tubing). It's from abrasion during transport that I didn't notice until it was too late. The spot is about 2cm x 2cm and most the worn area is white in colour (base coat or primer?) but there's a bit of rust forming in the center.

I'm not ready to get the frame totally repainted so what's the best way to get this patched up?

2 Answers 2

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The best method for handling exterior frame rust depends on how much time you'd like to invest. The difference comes down to what you use to complete the two basic steps:

  1. Remove the rust
    • Good: Sandpaper - Cheap, but wont remove all the rust, and may leave debris.
    • Better: Steel Wool - Will remove most of the rust, but may leave steel wool fragments, which can rust in turn.
    • Best: Brass Wool - Since brass will not 'rust' (oxidize) like steel, any fragments left behind won't cause the frame to rust.
  2. Cover up the spot
    • Good: Nail or auto polish - Not technically the best sealant, also will wear faster and will need to be re-applied.
    • Better: Auto or spray paint, primer, or a clear lacquer - More water-tight, longer lasting.
    • Best: Bicycle paint - This is a given. =]

The most important point to note, though, is to remove as much of the rust as possible before painting. Simply painting over the rust will just seal it in, and allow it to continue rusting away beneath the layer of paint.

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  • Would it need to be primed first? Do bike shops normally carry small amounts of bike paint?
    – darkcanuck
    Sep 1, 2010 at 23:22
  • Most types of paints should be primed first, but it depends on how much work you want to put in it. I wouldn't expect a typical bicycle shop to have frame paint, unless they do fabrications, restorations or actual frame painting. Sep 2, 2010 at 2:57
  • Do you mean brass wool like the kind for cleaning soldering iron tips? Mar 6, 2013 at 13:26
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I've typically cleaned the area and just used clear nail polish to seal it again. You have to do it every month or so but if you're vigilant then it works. Kept my 10 year old MTB frame fairly rust free with this method.

I'd also be interested in better methods that seal longer term.

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