As much as we swear by duct tape, zip ties, superglue, and epoxy for field-expedient repairs, there are some things these materials can't fix — at least not in a way we'd consider permanent. Cracks and splits in small gadgets (or your skin) can be patched with cyanoacrylate superglue, and larger breaks can be repaired with a two-part epoxy like JB Weld. We've even heard of broken engine blocks being fixed temporarily with epoxy. But if you're aiming to bond two metal parts properly, JB isn't gonna cut it. You need a real weld.
Welding is often associated with expensive machines, specialized fuels, and years or decades of training. However, you don't need to be a pro welder with high-dollar gear to apply a quick bead and join two metal parts. Stick welding (a.k.a. SMAW or shielded metal arc welding) is one of the easiest methods to learn, and it's relatively forgiving even if you're working with metal that's not exactly squeaky-clean, so it's ideal for emergency gear repairs.
Note: Welding can be extremely dangerous, especially if attempted without adequate protective gear. If you've never welded before, we recommend seeking out professional instruction at a local community college or trade school. Always take every safety precaution and only attempt these techniques at your own risk.
The other advantage to stick welding is that all you really need is electricity, a welding rod, and the appropriate protective gear. This means that it's possible to improvise a DIY battery-powered stick welder. The YouTube video below from Dennis Evers shows a way to make a welding setup with four discarded 5000 mAh industrial batteries, some 10-gauge copper stereo wire, standard wire connectors, and a dollar store metal spring clamp. The batteries are wired up in series (i.e. positive to negative) to deliver approximately 50 volts.
As Dennis says in the video, the DIY stick welder system isn't for building a ship or a precision aircraft, and it's probably not going to produce the prettiest welds (especially if you're a beginner). But it's a good resource if you ever need to make some quick repairs to motorcycle, reinforce the hinges on an old metal gate, or tack a bracket onto your truck's bumper. The same principles can be applied with two or more car or truck batteries and some jumper cables, if you don't have the luxury of smaller industrial batteries.