Silver Brazing
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Silver Brazing
Hi, I'm receiving a new (actually old, but new to me, and not used a lot) Erba NJS track frame. My coach got it and a U-Haul of other pro-Keirin stuff from an ex-Japanese pro now situated in Detroit. He'd giving me the frame for practically free. The only problems are:
1.) For some reason, this racer drilled brake holes in the fork and rear stay bridge.
2.) During shipping, an axle put a small dent into the down tube.
My coach says that I could use silver and braze everything up with a propane otrch since I don't have access to an acetlyne torch.
So my questions are:
1.) Will silver and a propane torch be suitable?
2.) Will the fork and bridge be as structurally safe as before?
3.) When brazing the holes, should I put something behind the hole, or should I just plug it up by making the hole smaller and then filing?
1.) For some reason, this racer drilled brake holes in the fork and rear stay bridge.
2.) During shipping, an axle put a small dent into the down tube.
My coach says that I could use silver and braze everything up with a propane otrch since I don't have access to an acetlyne torch.
So my questions are:
1.) Will silver and a propane torch be suitable?
2.) Will the fork and bridge be as structurally safe as before?
3.) When brazing the holes, should I put something behind the hole, or should I just plug it up by making the hole smaller and then filing?
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I don't understand why you would want to fill the holes. Assuming the crown was drilled through a solid section the hole won't hurt anything...in fact, you could throw a brake on there if you are going to ride the bike on the street at some point. Brake bridge hole won't hurt anything either. Not sure I'd put a brake on it though since many track frame rear bridges are not strong enough to support a real brake. At any rate, you will gain nothing structurally by filling the holes.
BTW, propane does not get hot enough for brazing. Some low budget people use MAPP gas though which is reputed to work okay in a pinch.
BTW, propane does not get hot enough for brazing. Some low budget people use MAPP gas though which is reputed to work okay in a pinch.
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Originally Posted by Nessism
BTW, propane does not get hot enough for brazing.
Last edited by PaPa; 07-05-07 at 11:57 AM.
#4
Mitcholo
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Originally Posted by Nessism
I don't understand why you would want to fill the holes. Assuming the crown was drilled through a solid section the hole won't hurt anything...in fact, you could throw a brake on there if you are going to ride the bike on the street at some point. Brake bridge hole won't hurt anything either. Not sure I'd put a brake on it though since many track frame rear bridges are not strong enough to support a real brake. At any rate, you will gain nothing structurally by filling the holes.
BTW, propane does not get hot enough for brazing. Some low budget people use MAPP gas though which is reputed to work okay in a pinch.
BTW, propane does not get hot enough for brazing. Some low budget people use MAPP gas though which is reputed to work okay in a pinch.
Either way, the dent at least needs to be filled. Are there any lower cost alternative brazin techniques? I might be able to find someone with an oxy-acetlyne torch, but I've only used oxy-acetlyne to cut metal, not braze.
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Originally Posted by CrimsonKarter21
This is a track only frame, I'm not a hipster. I also want it to be as aero as possible without interruptions in the wind. Neither of the holes were supposed to be there in the first place.
Either way, the dent at least needs to be filled. Are there any lower cost alternative brazin techniques? I might be able to find someone with an oxy-acetlyne torch, but I've only used oxy-acetlyne to cut metal, not braze.
Either way, the dent at least needs to be filled. Are there any lower cost alternative brazin techniques? I might be able to find someone with an oxy-acetlyne torch, but I've only used oxy-acetlyne to cut metal, not braze.
Fill the holes with bondo or epoxy if you must. Brazing them closed will do nothing positive for the frame and will ruin the paint job.
The lowest cost braze worthy torch is a MAPP gas torch - looks similar to a Propane torch but burns hotter.
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A carbon arc torch on a 230 volt arc welder works well, too. For those unfamiliar with a carbon arc torch, it is a "V" shaped device you hold by its handles and squeeze together. There are also two holders for carbon rods. Squeezing the handles brings the carbon rods into contact. They get very hot. The user allows them to spread apart slightly and a brilliant hot arc forms between them.
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if you're that worried about wind resistance then you should be petrified about the additional weight brazing would add to your frame. Use duct tape.
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Originally Posted by CrimsonKarter21
This is a track only frame, I'm not a hipster. I also want it to be as aero as possible without interruptions in the wind. Neither of the holes were supposed to be there in the first place.
Either way, the dent at least needs to be filled. Are there any lower cost alternative brazin techniques? I might be able to find someone with an oxy-acetlyne torch, but I've only used oxy-acetlyne to cut metal, not braze.
Either way, the dent at least needs to be filled. Are there any lower cost alternative brazin techniques? I might be able to find someone with an oxy-acetlyne torch, but I've only used oxy-acetlyne to cut metal, not braze.
#9
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I think Bondo would be the best option in the end, the steel is pretty thin, and even though I know how to use everything, I can't trust myself to mess around like that.