Brazing

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Brazing

Postby KDXrider1989 » 06:26 pm Jul 24 2012

The end of my FMF muffler has been screwed up since I bought it used and have tried JB weld to close up a crack at the end only to see it leak again in about 5 rides. I had plans on sawing off the old, beaten-up end of the canister and braze on a new end out of 3-inch flat aluminum, I would like to have it welded but that is ridiculously expensive. Do y'all know if brazing is a good idea, and if it can stand the vibration, oil, and heat of the exhaust?
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Brazing

Postby SS109 » 07:35 pm Jul 24 2012

Try brazing the crack closed? I bet that would work better than making a whole new end. Anyways, brazing will handle the oil and heat at the tip no problem. Vibration could be another issue but I would bet it will hold fine if the brazing is done right.
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Brazing

Postby the machinist » 08:41 pm Jul 24 2012

If you pay the shipping I will weld it for you, free. I now have way to much free time, see *graphic picture* post. Brazing might work but welding is better.
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Brazing

Postby KDXrider1989 » 09:02 pm Jul 24 2012

SS109 wrote:Try brazing the crack closed? I bet that would work better than making a whole new end. Anyways, brazing will handle the oil and heat at the tip no problem. Vibration could be another issue but I would bet it will hold fine if the brazing is done right.

I was going to replace the whole end for cosmetic purposes, it's all dented and ugly-looking. But if in fact brazing cannot hold well against vibration, then I guess I'd have to just close the crack and see what happens
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Brazing

Postby KDXrider1989 » 09:04 pm Jul 24 2012

the machinist wrote:If you pay the shipping I will weld it for you, free. I now have way to much free time, see *graphic picture* post. Brazing might work but welding is better.

Wow, thanks! But this is something I'd like to get done in one day because I might go for a ride this weekend
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Brazing

Postby Slick_Nick » 11:19 am Jul 25 2012

KDXrider1989 wrote:
the machinist wrote:If you pay the shipping I will weld it for you, free. I now have way to much free time, see *graphic picture* post. Brazing might work but welding is better.

Wow, thanks! But this is something I'd like to get done in one day because I might go for a ride this weekend


Then brazing is the way to go.
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Re: Brazing

Postby KDXrider1989 » 11:51 pm Jul 25 2012

got some rods today and tried to seal the crack. no deal. this stuff is kinda hard to work with
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Brazing

Postby Slick_Nick » 09:28 am Jul 26 2012

Probably you heated the rod and melted it which is incorrect. Heat the exhaust cap, then touch the rod to it (without direct flame) and it will flow in nicely. If you just heat the rod, it will sit "on top" of the cap and not adhere. Wire brush and use a good flux if need be.
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Brazing

Postby Slick_Nick » 09:29 am Jul 26 2012

This guy does it great and shows the WRONG way to do it too.

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Re: Brazing

Postby KDXrider1989 » 10:58 am Jul 26 2012

I did heat the rod directly, and the aluminum did pretty much sit on top and not bond. I have flux-core rods, the guy in this video looks like he's using more of a solder. I'm going to go try this right now and see what I get
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Brazing

Postby Slick_Nick » 12:57 pm Jul 26 2012

I use pure aluminum rods, and a paste flux when I need it. You MUST heat the base metal and not the rod.
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