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Makeshift repairs and babbit

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MachineNLectricMan:
   I was reading some posts about makeshift bearing journal repairs and there were surprisingly few mentions of babbit metal. Our early American railroad westward expansion was built with babbit bearings. The unique feature of this material was easy field repairs without needing machine shop equipment or having to keep a large inventory of spare parts. My grandfather use to often talk about this metal. In today's times with shortages all over, maybe it's time to re-visit this material.

   There are many different variations of babbit alloys for high speed, low speed, heavy loads, ect.. If I remember right, the metal expands slightly when it solidifies, so it adheres well to clean and properly prepared bearing case bores. Sometimes these bearing case bores were just rough cast using green sand molds at the cast iron foundry with no machining needed before the babbit was poured in. The shafts were simply coated with some greasy release material or special paint, centered in the bore and the metal poured in. Clay was often used to seal the bottom and any gaps, and if an oil hole was needed, a coated steel, or iron rod was inserted before pouring. After pouring, and when cooled, the shaft was removed easily if everything was done right, and the proper clearances were hand scraped into the bearing bore, along with smoothing out any imperfections.

   Also, the metal was extensively recycled in the field. When a bearing got excessively worn, the old metal was removed, often by melting, then it was re-melted and some extra metal added to make up for metal lost from wear and any melting slag, then re-poured back into the bearing case to form the renewed bearing.

   If babbit can support locomotives weighing more than 100 tons, it ought to work well for any emergency Lister repair if you choose the correct alloy, and I believe the early Lister's actually did use babbit. Henry Ford was likely responsible for the demise of the widespread use of this metal because he needed interchangeable parts for his auto manufacturing.  Although babbit was used in the early replaceable bearings, it was not well suited for thin coatings inside replaceable steel bearing shells.

   Sometimes modern technology throw's the baby out with the bathwater. Seldom does new technology actually completely eliminate the use or need for all of the older technologies. There is always some nich that only one type of technology does the best. We should think of new technology as adding another useful tool to the technology "toolbox", but not going and hastefully dumping out all of the other tools that will always have some special uses.
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cobbadog:
Sure, there is no reason that babbit bearings could  not be used in almost any old stationary engine. The hard part is sourcing the material easily then the preparation and setting up accuratly of the dummy shaft ready for pouring. Then the heating of the babbit material, pouring and finally scraping to size.
I have a few engines that run babbit bearings from mower engines, hit n miss engines and even a diesel engine made here in Australia.
At the end of the day the use of bearing shells is simpler and far easier to source and replace and is the main reason for the old system of babbit. So it would be the case of cost against effeciancy. I think I prefer bearing shells over babbit for convenience but there is nothing wrong with the way a babbit works or lasts.

mikenash:

--- Quote from: MachineNLectricMan on June 17, 2021, 12:49:50 AM ---   I was reading some posts about makeshift bearing journal repairs and there were surprisingly few mentions of babbit metal. Our early American railroad westward expansion was built with babbit bearings. The unique feature of this material was easy field repairs without needing machine shop equipment or having to keep a large inventory of spare parts. My grandfather use to often talk about this metal. In today's times with shortages all over, maybe it's time to re-visit this material.

   There are many different variations of babbit alloys for high speed, low speed, heavy loads, ect.. If I remember right, the metal expands slightly when it solidifies, so it adheres well to clean and properly prepared bearing case bores. Sometimes these bearing case bores were just rough cast using green sand molds at the cast iron foundry with no machining needed before the babbit was poured in. The shafts were simply coated with some greasy release material or special paint, centered in the bore and the metal poured in. Clay was often used to seal the bottom and any gaps, and if an oil hole was needed, a coated steel, or iron rod was inserted before pouring. After pouring, and when cooled, the shaft was removed easily if everything was done right, and the proper clearances were hand scraped into the bearing bore, along with smoothing out any imperfections.

   Also, the metal was extensively recycled in the field. When a bearing got excessively worn, the old metal was removed, often by melting, then it was re-melted and some extra metal added to make up for metal lost from wear and any melting slag, then re-poured back into the bearing case to form the renewed bearing.

   If babbit can support locomotives weighing more than 100 tons, it ought to work well for any emergency Lister repair if you choose the correct alloy, and I believe the early Lister's actually did use babbit. Henry Ford was likely responsible for the demise of the widespread use of this metal because he needed interchangeable parts for his auto manufacturing.  Although babbit was used in the early replaceable bearings, it was not well suited for thin coatings inside replaceable steel bearing shells.

   Sometimes modern technology throw's the baby out with the bathwater. Seldom does new technology actually completely eliminate the use or need for all of the older technologies. There is always some nich that only one type of technology does the best. We should think of new technology as adding another useful tool to the technology "toolbox", but not going and hastefully dumping out all of the other tools that will always have some special uses.
Modify message.

--- End quote ---

Catch up with Starfire here, and ask him about the coke-can-big-end shell adaptions - or just search for it here

38ac:
Actually some if not all modern engine earing shells still use a layer of babbit over the backing metal it serves to cushion shock loads and provide crankshaft protection. How thick depends on the application. Ford may have had something to do with thin shell development but Henry's Model Ts and As had poured babbitt bearings.
As for pouring an emergency repair bearing it is indeed a satisfactory repair when there is no other option. As an example there are no big end shells available for the Z4 Banfords engines. When I rebuild one the rod goes to a specialist who pours babbitt directly in the rod and adds a shim pack so it can be adjusted down the road if needed. Same would work for a CS type but when replacement shells in every conceivable undersize are easy obained and cheap there is really no reason go another route outside of an emergency repair and try to find Babbitt in your home town, might as well order a bearing as order babbitt.

scott p:
I use old poured babbit bearings on some of the sawmill shafts. I get the babbit from a comersial saw mill. They use the babbit in their gang saw. They call it high speed babbit or hard babbit.They also say it is lead free with a lot of tin.

I coat the shaft with a  coat of carbon applied by a Acetylene flame. As mentioned clay or something to seal the gaps. Poured directly through the oil hole and then drilled. No need to scrap. Works fine, no searching around for probably none existent bearing shells.

I am currently working on  replacing the small end bushing on a small, old, slow speed gas engine. I am not aware of any organization that sells bushings for these old engines. This hard babbit is a dream to mill. It will be a DIY schooling project. I might coat the wrist pin and pour the babbit around it and then machine it to fit the small end.

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