In my experience, I've replaced lead tubing on Standard actions so
often that I now simply assume that I will do it; I consider it part
of the rebuild.  Early in my career, I tried patching by cutting out
the leaks and putting 3/16-inch tubing in as a patch.  I soon learned
that as you patch one leak you disturb its neighbors and then you
have 2+ more patches to do.

It doesn't take much to break a lead tube.  The walls may look like
good lead but are often very thin by now.  Another problem, besides
the time and frustration, was that the patches took up space and
sometimes the bridal tape wires on the piano action would catch on the
tubing.  Now I treat Standards like players that had original rubber
tracker bar tubing and replace it with rubber tubing from Schaff.

Bad lead tubing gets what looks like a wart, usually where it makes
a gentle bend just above the entrance to the board at the back of
the stack.  Why there and not at other bends I don't know.  I've cut
through that spot and found just white powder.  I've cut just above
or just below and found shiny, unoxidized metallic lead, just as one
would expect.

I sometimes replace tubing on Autopiano stacks but not very often.
Rarely do I need to replace lead tubing on others, although I currently
have an Otto Higel in the shop that will need it.

Jeff Davis - in Seattle, where spring is nearly here!