This was kind of a fun project – an exhaust pipe that had rusted through on a pick-up noticed 30 min. prior to a 14 hour trip. How to reattach everything so that it doesn’t drop onto the highway. What ends up being important in this situation is the suspension. The pipe itself is not a straight pipe (see top on linked picture), which means that once it detaches (in effect vibrating itself off of the muffler end of the broken pipe), it reorients to obey gravity (apart from the rusted through end, there was only one point of attachment still left, and a few failed weld jobs along the pipe). So, the various forces have to be managed. How best to do it?
The pipe comes off when it is driven. The direction that connecting pressure has to be applied is along the long axis of the pipe across both disconnected ends. Since one very often observes a pipe break with ease when sealed only at one or a few points, it is probably a good idea for the connecting points to be spread out around the pipe ends that need to be sealed.
I pull together a short-term solution with some dog tie-out cable wire and u-bolt clamps, using a broken air-filter holder clamp with wire threaded through both ends as it encircled the pipe, and ratcheting it tight with the clasp. That was one end. The other end was simply threaded tight around an attachment point or failed weld plate. The pipe ends did end up pulling apart again a little with this strategy, but it stayed elevated, not dropping onto the highway. It might have held a little better if I had laced the wire back and forth across and around the pipe.
So, now I’m thinking we’re actually going to have to make some pipe to encircle the 2 rusted ends. I’m wondering if a tin can would do it, taking a can opener to both sides – the pipe is 3″, so it would have to be filled with something that is heat-tolerant. Cement would probably break, mud might work for a bit. Something would have to stabilize the can. It might need to be more than one can put together. Inside the pipe would be a bad idea, because the whole thing might dislodge under pressure shooting out like a projectile. If I do use the inside option, I could maybe tap the exhaust a little with a hammer before and after the sealed ends while it is hot so nothing moves.