cracked exhaust on 912ULS

Not sure what alloy they are made with but 316L alloy will do the job on all SS alloys.

Yesterday one of the local flying school Foxbat's, cut short a lesson,  landed early, due to unusual vibration at around 4000 rpm. 

On investigation, it was found that the centre section of the "tail pipe" had exited the muffler. The tail pipe was only prevented from completely leaving the aircraft by jamming up against the cowling.

The cowling had melted where the tail pipe was in contact with it.

I complimented the instructor & student for their decision to land.😈

The picture shown is not a Rotax ULS exhaust, it appears to be from something else.  Rotax Rotax 912 canisters have a round shoulder on the canister ends.  Is this perhaps something from your OEM?

Cheers

"Is this perhaps something from your OEM?"

I had the same thought RW however Dan's  problem  remains - getting the muffler canister repaired.

On an allied track - I don't see repairing the muffler as anything more than a temporary fix, pending replacement. Welding a thin metal, high heat/cooling, structure usually results in a short lived repair.

My concern is, what may the safety implication of  the muffler  failure "down the track"  eg CO poisoning/Fire😈

The issue is there is no way to determine the alloy of the metal.  Given this is to be a temporary fix perhaps it will not matter.  I would suggest, as with any exhaust, using a inert gas inside the muffler while welding the crack.  This prevents contamination of the inside and perhaps will last a bit longer while a replacement can be found.

Cheers