Propane to fix cracked rack?

[merlinmurph]

Regardless of how you try to fix the crack itself (weld, JB, etc), I would also fortify the joint externally. Someone mentioned fiberglass or carbon. Maybe figure a way to get PVC T-joint pipe around it and glue everything. Or some combination of those.

Still, do what you can externally to the joint. It has already been compromised and will probably never be as strong as it was originally.

I tend to over-engineer things like this.....

[45K10]

Originally Posted by m_sasso

Similar to suggesting Elmer's or bubble gum! If you desire to keep the rack have it tig welded.

Yes, Tig weld would be best but the OP will need to grind out the existing weld and add some more metal to fill in the crack. If the OP didn't already have a replacement rack I would suggest welding it but for a couple of bucks and about 30 mins you could get almost similar results with JB weld.

Back in my low income college racing days I fixed all kinds of bike stuff with JB weld:
Brake bosses, pedal axles, I even used it on an old steel frame with a cracked rear brake bridge that had been driven into a garage on top of a roof rack. All of the repairs held for as long as I owned them.

[ParkerMusselman]

Embarrassing as hell, but in my early days I used JB weld to affix a fender boss. It came unaffixed, the SHCS got caught in a spoke which pulled the fender into the tire, the tire (front) stopped dead, bent the fork, bent the down tube and left me on the ground in a matter of milliseconds. Epoxy works great in certain applications, like sleeving, but it's not good at taking the entire load.

This looks like just the foot of the weld has cracked and not the tube itself. :shrug: JB might hold for long enough and the consequences are low. I'd prep it and take it with a 12 pack to a local welding shop. It's a 5 minute job for anyone with a TIG setup.