Archie wrote:

In hard core racing, the same problems arose a number of years ago,
mostly in funny cars, but dragsters also. The common denominator,
other than various grades of stainless, was outside welds.
Now you may see some tack welds on the outside, but the actual
welding is done on the backside.(inside)
Also in current use is a tube within a tube.
I noticed the weld bead was quite wide, increasing the haz,
and may have contributed to the failure.
 Archie

Paul,
I don't have alot of experience in this but the motorbike exhausts seem to
work OK and their not welded.
It just seems having a rigid joint with this heat and expansion, is looking
for trouble.
How about a tube with a small flange being held in place with a bracket (but
not welded)- could include a crush plate for seal or silicone or both.
My 2c worth.
Thanks for the drawing on the Prop Hub.
George (down under)

 
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