[Steam-engine] Pitted shaft & Babbitt bearings

[Andy glines]

I don't think that leaving them alone will work this
time.  The shaft has corroded and area about 1"+ wide
for the length of the bearing surface on both ends. 
I'm thinking that rain water entered the grease cups
and sat on the shaft.  I should feel lucky that it
didn't pit the shaft all of the way around.  I'm
afraid that leaving a gap in the bearing surface like
this will cause the shaft to cut the bearing.  Several
folks on the SEL made the same suggestion though. 
There are a few options though.  Repair with JB and
redo the JB it it burns (big 3" shaft will act as a
heat sink and may prevent this).  Use a higher temp
product.  Pour before pits are repaired, scrape
bearing, then repair with epoxy.  Use a dummy shaft. 
I could weld repair the pits but I'm steering away
from this idea.  As usual the folks at ATIS are giving
me food for thought.  Thank you.
--- Ken Hough  <k4sb at niia.net> wrote:
> Andy, I think you are making more of this than need
> be. Don't bother 
> filling the pits. Its not turning that fast. Get
> some roll sandpaper and 
> buff the axle like shoe polisher does. Go all around
> it. Wrap the axle in 
> butcher paper. Todays news paper is too flexible.
> Oil it up with 600w
> and lay the paper on. use some thread if it wants to
> undo itself. Tin the 
> bearing housings with some acid core solder. This
> bonds the babbit to the 
> housing. Support the shaft with hardwood wedges (not
> deep) on the bottom 
> and sides and dam it up. Use Babbit Right.
> Pre heat the housing and pour the first half. Let
> cool.  Remove the shaft 
> and re wrap with paper. Set it in the bearing half.
> Lay a very flat .005 
> shim brass (or oiled paper works too) over the
> cooled babbit.(this 
> prevents the babbit from bonding with the bottom
> babbit) Add 1/8-1/4  inch 
> of shims. Install the top bearing half and dam it
> up. Preheat and pour. 
> Let cool. Dissassemble and remove the paper. The
> pits will hold oil 
> helping to lube it. with a dremel tool and a round
> deburring bit create 
> oil grooves. Reassemble. You must tin the bearing
> caps. This really helps 
> bond the babbit. 
> Ken
> 
> 
> 
> 
> 

Andy Glines
Evansville, IN

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