Michael Horowitz wrote in
:

On Thu, 20 Sep 2007 04:46:45 +0000 (UTC), Fortunat1 wrote:

clare at snyder.on.ca wrote in
news:r3k3f35vka26ss9jq6k80m2cr1ef67usun@ 4ax.com:



This is tubing, right? Drill a couple of holes and rosette weld, or
plug weld the sleave in place. It is now doing it's job Now weld the
ends of the tubes together. If the weld penetrates into the
re-enforcement sleave, good. If it doesn't the sleave is still in
there providing extra strength to the joint (done properly, the
joint is almost strong enough with just 4 plug welds per end)


This makes sense to me, however, looking in my books, it's stated
pretty clearly that the inner tube should be welded to the outers.
there's a copy of that text he

http://www2.tech.purdue.edu/at/cours...Links/Ac43-13-
1B
/CH4 _5.pdf

Now, it would seem to me that penetration of the inner tube would add
very little strength at all, particularly if it was a good snug fit.
Am I reading this wrong?

You're quoting a very general section. If you could cite the specific
sub-paragraph it might help - Mike



Sorry. Scroll down to 4-84.
There's a whole section on the type of repairs you're talking about.
4-84 specifically mentions including the innner tube into the weld. It
seems to me that the weld area would be at least as strong without
welding across the inner tube like that. If you weld a doubler on the
end of a strap, for instance, you don't lap weld across the widthe of
the strap where the thickness steps down, you only edge weld around the
outside perimeter. That would indicate to me that welding across a piece
of tubing, unneccesarily, only puts stress risers around the weld. If
it's a snug fit, you've got to have at least the same strength there you
had with the original tube.