I figured the plug would have to be a similar alloy or you would
have a problem with expansion.
I had some cast iron that couldn't have been saved by stitching,
so it had to be welded. I've been welding for most of my life
in one form or another. My pop was a maintenance welder at a
Reynolds aluminum plant back when I was a kid in the 50's and he
taught us the basics as soon as we were old enough to hold a
torch. So I do understand the headaches with welding cast iron.
I don't think people realize just how hard a weld is after
welding cast iron. I had a perfectly good manifold on my '50
except for an ear broken off the exhaust flange:
http://www.pbase.com/dennygraham/image/136649244

To just build up the ear was not a good solution because I would
have been tapping into the weld bead so I opted to cut it back
clear of the stud and weld a new piece of material on to the
outlet. That would give me a clean base to tap into:
http://www.pbase.com/dennygraham/image/136649428

Once I had the new tab welded on then I used a drill fixture
that I'd made for drilling flanges:
http://www.pbase.com/dennygraham/image/136650521
I tig welded this using a silicon bronze eutectic rod and it's
held up just fine for the last three years, no "tink" yet.


DG





Denny G
Sandwich, IL