[SEL] Babbitt Lapping Compound

[Richard Strobel]

What comes to mind Curt,, and Elden and the Doc might remember is the old 
cleaner used on TV rotary tuners.  First it was a mild abrasive, then 
polished and I believe lube might have been the last result....might need 
help on the lube part :-))

  If in fact this compound did the above, I would be willing to try it on 
some babbitt....diamond would be a definete no-no with babbitt, IMO.

  What I've got now is a super heavy single throw crank with the rod throw 
radius' out of whack and un-even.  The rod throw mates to bronze inserts 
which show evidence of the un-even radius' (sP).  I'm thinkin' a visit to 
the crank Doc in Missoula is in order.  He did a great job on the Gal after 
the wreck.

and Jack might be right..I was impressed on how forgiving pumice is to 
porcelain....very hard water deposits here.


  Will do more research with the guy that uses it on his Model A's.


Take care...warm fall here so far....priority now is wings on the 
snowplow....aaarrghhh.


Rick











Rick,
When I use lapping compound on bushings for our forging machines here at
work, I remove the cap and place a small amount of the compound at the
point along the bushing & shaft where the bearing is tight. I place it
at the junction between the shaft and edge of the bearing, where the
shaft rotation will sweep the compound into the bearing. I then put the
cap back on loose and fit a large funnel to the oil inlet. Then run the
machine and slowly pour about a quart of oil (320 vis) thru the funnel,
literally attempting to wash the compound, and the wearing away bearing
material out of the bearing. I use diamond lapping compound (5 micron)
and it works in seconds, so getting it back out of the bearing is of
paramount importance, otherwise a low bearing results.
This process is on 660 brass bushings. I have never tried on babbitt
bearings. They claim it does not imbed in the babbitt, but that would
sure be my concern. I lean very strongly to "scraping" the high spots
away on babbitt. Babbitt is SO easy to work with, one could almost get
the "lazy" title associated to their name if they aren't will to invest
a minimal bit of time scraping in soft babbitt bearings. I don't even
use official scrapers on babbitt, just hit the high spots with a very
course rat tail file. This works great and is fast.
Curt