seeker333
03-08-06, 04:03 PM
I have a dedacciai steel mtb frame that i use on road / bikepaths only, no rough stuff.
The frame developed a ~7 mm long hairline crack shortly after i built it up, at the interface of the right chainstay to dropout, on the bottom side, extending ~1/3 across width of joint. The dropout is breezer brand with single eyelet, and is brass brazed to the stays. China built bianchi branded frame.
It has been this way for months and i have continued to ride it ~4,000 miles. I put a mark on it to mark end of crack - it has not changed since i first discovered it.
So i've been thinking of getting a cheap benzomatic mapp rig, the special one with the hoses and small tip. And some brass rod.
I've soldered many things and can do this fine, so i expect i can make a simple bicycle frame repair.
Here's my question: How do i fix this joint? I'm guessing i need to file/cut down directly thru the cracked joint to some depth, say ~2 mm, clean, then fill her in with brass, cool then file sand and paint. I recall theres some flux or equivalent required also.
Am i close? Thanks for any advice.
PS - What kind of brass alloy should i be looking for at the local welding supply shop? The folks that work there don't seem to be familiar with the phrase "brazing", or the general concept of using brass rod to join steel.
The frame developed a ~7 mm long hairline crack shortly after i built it up, at the interface of the right chainstay to dropout, on the bottom side, extending ~1/3 across width of joint. The dropout is breezer brand with single eyelet, and is brass brazed to the stays. China built bianchi branded frame.
It has been this way for months and i have continued to ride it ~4,000 miles. I put a mark on it to mark end of crack - it has not changed since i first discovered it.
So i've been thinking of getting a cheap benzomatic mapp rig, the special one with the hoses and small tip. And some brass rod.
I've soldered many things and can do this fine, so i expect i can make a simple bicycle frame repair.
Here's my question: How do i fix this joint? I'm guessing i need to file/cut down directly thru the cracked joint to some depth, say ~2 mm, clean, then fill her in with brass, cool then file sand and paint. I recall theres some flux or equivalent required also.
Am i close? Thanks for any advice.
PS - What kind of brass alloy should i be looking for at the local welding supply shop? The folks that work there don't seem to be familiar with the phrase "brazing", or the general concept of using brass rod to join steel.