Check out the Yellow Pages for " metal spray". There are a number of
industrial processes that are used to build up worn shafts. The shaft is
usually set up on an old lathe and a powdered metal mixture is trickled into
an oxy/acetylene flame. The flame drives the metal onto the preheated shaft
where it sticks quite well. The shaft is then machined back as usual. For a
cheap & nasty solution Google" LocTite" for a product called "bearing
tight" . Its not perfect but its better than a wobbling shaft

Tom
wrote in message
ups.com...
I heard of something once that worked like form-a-thread I believe.
You put a paste on a worn area of a shaft and when it cured you could
machine it back to the original diameter.
We have a shaft in an old horizontal mill. One end is worn about .030
and fits into a bearing. They have been running this machine slotting
screws for years but I want it fixed. This seeems like the easiest way
if it works.