Classic & Vintage - Rust Hole

I was looking over my bike when I found a rust spot on the inside of the chainstay with a hole in the middle of it about 1-2mm in diameter. Is this dangerous/possible to fix?
http://i171.photobucket.com/albums/u295/Shokd/IMG_1065.jpg

I would edge towards dangerous.

That looks more like the rear wheel was (often) not installed properly and rubbed a hole through the chain stay. Am I correct that this is on the non-drive side?

A good welder can fix that hole. Shouldn't take more than a minute to repair but it will require a repaint!

Yep, it's non-drive side. How much would it cost for a welder to fix it? I was thinking of doing a repaint sometime anyways.

if you go to a bicycle professional (a frame builder) he might use silver solder or brass and braze it, or he might use TiG welding to fill it in. This could cost something like $60 (maybe more) but would be done carefully and with low heat. OR you could take it to anybody with a MiG welder (point & shoot) like a shade-tree mechanic or a muffler shop worker on lunch break, and for anything from a 6-pack of beer to $20 bill, get him to shoot a gob of MiG wire weld into it. That might be messier, but you'd get to file it down (and you wanted new paint anyway).

if you go to a bicycle professional (a frame builder) he might use silver solder or brass and braze it, or he might use TiG welding to fill it in. This could cost something like $60 (maybe more) but would be done carefully and with low heat. OR you could take it to anybody with a MiG welder (point & shoot) like a shade-tree mechanic or a muffler shop worker on lunch break, and for anything from a 6-pack of beer to $20 bill, get him to shoot a gob of MiG wire weld into it. That might be messier, but you'd get to file it down (and you wanted new paint anyway).


+1 for this direction, though they would probably simply braze a 'patch' to cover it making it almost as good as new strength wise. I would atleast get a quote from a local builder before I thought of having it mig welded.

A good welder can fix that hole. Shouldn't take more than a minute to repair but it will require a repaint!
I would silver solder a patch over the hole rather than weld. Less heat damage to the already compromised tubing.

I can't tell where you are, but if you're near northeastern Wisconsin I could do it for you.

How long have you had the bike?
How do people ride with the tire rubing and not notice?

+1 for this direction, though they would probably simply braze a 'patch' to cover it making it almost as good as new strength wise. I would atleast get a quote from a local builder before I thought of having it mig welded.

That sounds good.


I would silver solder a patch over the hole rather than weld. Less heat damage to the already compromised tubing.

I can't tell where you are, but if you're near northeastern Wisconsin I could do it for you.

Nah, I'm in CT, but thanks for the offer. :thumb:

How long have you had the bike?
How do people ride with the tire rubing and not notice?

I've had it.. 2 weeks, I think. I wasn't the one riding with it rubbing, and just noticed the spot now.

By "silver solder," do you guys mean like the stuff you buy at radioshack?.. Doubt that's what you mean, but I do that kind of soldering all the time with electronics.. is it the same thing?

no it's called "solder" but that's a misnomer, it's actually brazing but not with brass or bronze alloy, rather with an alloy that has *some* silver content. If you haven't done brazing before, let an expert have at it.

Got it. Thanks guys!

I would silver solder a patch over the hole rather than weld. Less heat damage to the already compromised tubing.

While I won't argue the value of silver solder techniques, I will add that experienced welders using low amperage and flux core wire will generally perform a better repair. By reducing heat transfer to the surrounding material due to less actual operation time and the fact that the hole is actually repaired the area will be as strong or stronger the before the damage occurred .
Yes there are hacks that will just spin a roll of wire to cover their lack of skill but in the hands of a talented welder a quality repair can be achieved. Brazing, soldering and other such techniques have their place for sure but IMHO not in the repair of a structural member such as a chain stay.

I think a *good* welder would be able to properly fix it for less money. If this is a collectible bike or has strong sentimental value, I'd at least get a quote from a frame builder. I don't know too much about high-end frame repair, but I do know a few welders that would be able to patch that hole in less than 15 min (not including finishing) as long as it's just plain steel.

Yeah, I emailed a frame builder for a quote.. if that'll cost too much, I'll track down a good welder. Thanks for the advice all. :thumb:

I would silver solder a patch over the hole rather than weld. Less heat damage to the already compromised tubing.

I can't tell where you are, but if you're near northeastern Wisconsin I could do it for you.

+1. A patch on the outside of metal shaped to fit around the tube - or if you're really keen, do what I did in a similar situation. Make a shaped patch to fit inside the tube. Drill two small holes in the middle of the patch and pass a length of fuse wire or florist's thin wire through it. Hold the free ends of the wire and pass the patch through the hole into the tube. Pull on the wire to position the patch in place and tension and tie the wire around the opposite stay to hold it in place. Use a small Butane/Propane canister torch if you don't have access to a bottled gas set-up and use silver 'brazing' rod with flux to run a seam around the edges of the hole and the exposed patch. Use the same method to build on top of the patch to fill it. Let it cool and file/sand it to match the rest of the stay. Total cost £16 Sterling (about $25 US I guess) You will char the paint in the area of the repair but may be able to prime it and then blow it in with a matching aerosol - although I found it easier to strip and spray the whole frame. The repair will be as good as new. In future, make sure your wheel is secured!

Good luck!

That sounds doable... I assume I'd make the patch out of steel? What thickness did you use, and where'd you get it?

That sounds doable... I assume I'd make the patch out of steel? What thickness did you use, and where'd you get it?

Just a small piece of thin steel I had lying around on the bench - originally a mounting plate for the igniter on our old gas fire! (Nothing goes to waste in my workshop, but it's often hard to move around! It was about 1mm thick so fairly easy to bend it around a solid jack handle to get the right curve, then cut and grind to an oval shape that would "post" through the hole in my stay. I drilled the small holes after shaping it to make sure they were in the part that was exposed when in position. After tacking the edges I unwound and removed the wire before filling the centre. The finished repair doesn't show and hasn't cracked at all. This way you can monitor that - with a patch on top it would be hard to check.

Good Luck!