# Babbitt bearings 101?



## Olddaddy (Mar 28, 2021)

I am rebuilding a Chattanooga #12 Improved sugar cane mill, three rollers.  The shafts are in tough shape, so plan is to turn them undersized and sleeve them back to full dimension.  I need to pour all new bearing and have never worked with babbitt before.  I want to turn tubes slightly oversize of the finished shafts and use them as placeholders I can pour around.  Question, will the babbitt stick to them?  Can I wrap them in aluminum foil?  Is there a coating I can use as a release agent?  All that being said, I need a source and an idea of what to buy.  I'm pretty handy, but this is not a topic I am fully educated on.  Any advice would be greatly appreciated.


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## Ulma Doctor (Mar 28, 2021)

Great video here


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## Dmorgan855 (Mar 28, 2021)

I have not done this yet but I have a friend who has an old Cane Mill that has asked me to make new bearings for him. He plans on making his out of food grade plastic. This seems to be what people in this old machinery community are doing so they can use the cane mills since the Babbitt bearings may cause issues with food quality. The great thing about the plastic is it’s easy to machine and readily available through McMaster or other supply houses.


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## T Bredehoft (Mar 28, 2021)

Oil the dummy shafts, the heat will/may smoke the oil but oil will keep the babbit from sticking.


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## Olddaddy (Mar 28, 2021)

That was really great!  I know there is an intimidation factor, but I think I  can manage this.


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## f350ca (Mar 28, 2021)

Light the oxy acetylene torch without the oxygen, use the soot off the flame to coat the shaft. Acts as a high temp mould release for babbitt. I've always used the existing shaft as the core, then scrape the bearing for clearance. Don't overheat the babbitt or I believe its the zinc you burn off, pour it when it turns a pine stick light brown. Preheat the bearing case and shaft so as not to chill the liquid babbitt.

Greg


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## benmychree (Mar 28, 2021)

Another very good coating for babbiting is milk of magnesia, preheat the shaft and brush it on, it will provide clearance and prevent the babbit from sticking, soot from acetylene works well also,  I am not aware of any babbit formulations that include zinc as part of the ingredients, most have lead, tin, antimony and copper, for food contact, I would not use a lead based babbit, but would use a tin based babbit, some called high speed nickel babbit would work; the nickel comes from the use of monel for the copper source, since monel is a copper/nickel alloy originally derived from a native ore body.  Babbit metal is not the least bit cheap, especially in the high tin alloys.  Tin and antimony oxydises on the surface of the melt and it is lost if skiimed off as dross, I use rosin as a flux to reduce the oxides and prevent the loss of the oxides to the alloy.


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## benmychree (Mar 28, 2021)

Another necessity for babbiting work is "Dambabbit" or as we called it, bear **** --- used to seal up gaps where the molten metal could run out.


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## aliva (Mar 29, 2021)

Keith Rucker has video on this same cane crusher repair


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