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Will epoxy adhere to metal?
Look up the billboard adverts for Araldite epoxy glue. Yes.
As for the aluminum brazing rod: be sure to bring along a couple of stainless steel toothbrushes to thoroughly clean the surfaces of all oxidation before welding. Give it a fresh surface to adhere. I don't know why, but stainless works and other brushes create joints that fail on me. Use a stainless "fan" brush for spreading the stuff too. The right word escapes me, but they are a little fan shaped brush. Don't mess with anything but stainless. When you want them to hold, you really want them to hold!
Nice thing about the stuff: you can bring a propane torch head in your river hardware kit or use the propane from your camp stove to heat larger pieces for repair. Might have to wait your turn or fight with the cook, but they'll eventually let you use the propane.
I don't carry TIG or MIG welders on the river.
 

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Discussion Starter · #22 ·
I used aluminum brazing rods to achieve the same function last year.

I don't have a long term durability test yet but I put 8 on 9 days on this frame last year and nothing moved.
View attachment 72974 View attachment 72975
Tell me more about the aluminum brazing rod process. This looks like it would be interesting for the corners.
 

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Tell me more about the aluminum brazing rod process. This looks like it would be interesting for the corners.
It's kind of like soldering. You heat up the piece and melt the rod into the joint.

It would be easy to pack them and a propane torch in your repair kit.

The above poster is correct that you need to remove all oxidation before you do the braze.

The "repairs" I did using brazing rods have held up perfectly so far.
 

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For a decade I had a machine shop and made custom bicycle frames. Mostly lugged and fillet brazed, but some TIG as well. That "braze" on the speed rail above is kinda like a slip fit lugged joint, but the fitting is wayyyy to loose. It's kinda "tack" brazed at best. Anyways, the answer is to just pin the joint, or get someone to tack weld them all together. Epoxy really isn't a solution on something like a foot bar where you will be putting a lot of stress on the joint and the only thing holding it in place are set screws and expoxy without any kind of mitered joint.

Example (though it's steel) of a fillet braze on the head tube and then a half lug on the top tube:
Hand Arm Leg Wood Gesture
 

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For a decade I had a machine shop and made custom bicycle frames. Mostly lugged and fillet brazed, but some TIG as well. That "braze" on the speed rail above is kinda like a slip fit lugged joint, but the fitting is wayyyy to loose. It's kinda "tack" brazed at best. Anyways, the answer is to just pin the joint, or get someone to tack weld them all together. Epoxy really isn't a solution on something like a foot bar where you will be putting a lot of stress on the joint and the only thing holding it in place are set screws and expoxy without any kind of mitered joint.

Example (though it's steel) of a fillet braze on the head tube and then a half lug on the top tube:
View attachment 82082
I hear what you're saying but I will never pin a speed rail fitting again.

About 90% of the fittings I drilled and pinned have split at the seam, right where I drilled them.

I agree it's a tack more than anything but in my case it's cat frame spreader bars and so far is holding up fine. And I'm using the set screw as well.
 
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