In a message dated 12/31/2003 11:37:44 AM Central Standard Time, ALVentures@cox.net writes:

<< I was surprised (and disappointed) when I got my tangential manifold
muffler done by a FAA certified welder to find that it is welded on the
outside.  It is .058 inconel into the RB flange.  Same guy did Dave
Atkins, so his is probably the same way and apparently still is fine.
It's definitely a source of concern to me.   

Al
 >>

I don't think it is much of a factor for any material other than carbon steel. Lynn E. Hanover