I read Randy Bergum's article (linked in Robbie's notes) on repairing
cracked Deagan chime tubes with great interest.  It sounds like a
comprehensive solution to this common problem with older chime tubes.

  http://www.octos.org/ooth/repairs/chimetube/chime_tube_repair.htm 

I have a 1914 set of Deagan Class A chime tubes that have the plugs in
both ends of the tubes.  When I got them from a friend many years ago
about half the tubes had cracks at the bottom.  At the time I presumed
that since they were stored on the ground, moisture got into the bottom
of the tubes and started rusting the plugs.

About 30 years ago I took the smallest tube to an older gentleman who
ran a machine shop in my town.  He removed the bottom plug and ground
a V-shape groove up the length of the crack, drilling a hole about a
quarter inch beyond the end of the crack and extending the groove, like
shown in the photos of Bergum's article.

He then used a hand torch to fill the crack with German silver solder.
After it cooled he filed the added material to match the cylindrical
profile of the tube.  It sounded fine when we struck it.  I never did
get around to fixing any of the other tubes or put the plug back in
since I did not have the original striker mechanism, so this was an
experiment that had no follow-up.

These chime tubes have been hanging unused in my shop for 26 years now.
I just went over to check out the repaired tube and it still looks fine
where it was repaired.  I struck it with a mallet and it sounds as
clearly and resonates for as long a time as the uncracked tubes.  If you
don't have access to a TIG welding system and are willing to experiment,
this [silver solder] method might work for you.

Many years ago I met Gilberto Serna of Century Mallet Instrument
Service in the Deagan Building in Chicago.  He worked for Deagan and
repaired Deagan instruments for many years after they closed.  Century
is still in the Deagan Building but Gilberto has passed the baton to
his apprentice.  They might have some ideas to add to this discussion
based on years of experience: http://www.centurymallet.com/ 

Larry Kerecman