View Full Version : Anyone know how to pour Babbitt Bearings?
Pangea
06-11-2010, 09:43 PM
There is an old watermill across the street from my property. I was figuring that if the SHTF and things went all the way Mad Max, I could get that old wheel gear rebuilt and fab a new wheel for a generator/water pump.
I'm betting that the old bearings were the "pour in place" type. This is fast becoming a lost art. Anyone here know about this process?
Wyoming
06-11-2010, 10:00 PM
Hit the link below and it should at least get you familair with the process. Only pratical bit of information I can give you is to use your oxy/acetylene torch and 'smoke' the mating surface black with soot to get a good release on the babbitt.
http://www.lindsaybks.com/bks4/babbitt/index.html
FarmBoy9205
06-11-2010, 10:21 PM
There is an old watermill across the street from my property. I was figuring that if the SHTF and things went all the way Mad Max, I could get that old wheel gear rebuilt and fab a new wheel for a generator/water pump.
I'm betting that the old bearings were the "pour in place" type. This is fast becoming a lost art. Anyone here know about this process?
There is a reason it is a lost art. There are a lot better processes available today. Can you use pillow blocks and nylon or brass bushings?
Pangea
06-11-2010, 10:26 PM
I don't think that pillow blocks for a 4" shaft would be a cost that I would want to bear. Gonna do my homework on Babbitt Bearings.
SmokinPRanch
06-11-2010, 10:30 PM
If the base bond is good you can puddle babbit bearings, assuming they are 2 piece. A quick check of the bond is to tap the shell. If it rings it's generally a good bond.
When I worked for an electric motor we did tons of babbit bearings. Some were poured and I know the fella that did it would tin the base before doing it. But as you said, it's a lost art, mainly because spin casting is so much better and widely available.
Any way you go there is quite a bit of machining to do.
Al
enlpck
06-11-2010, 10:49 PM
I've done it, but am not an expert.
The surface accepting the babbitt needs to be clean, and should not be smooth. Typically, the surface will be milled with grooves, slotted so that the bearing metal can key in, have holes drilled through, or some other method to mechanically assist the hold, as the bearing metal will tend to creep, and will separate from the base material in service (peel) if mechanical attachment isn't provided.
Prep for the surface to receive that metal requires melting or cutting the old material out, degreasing, and, if there isn't a layer left in place that is complete and well bonded (NO oil under it, peeling, separation, or other flaws), it should be cleaned down and tinned with tinning butter (it is available made up. Flux and powdered tin based white metal). Application is straightforward: clean the base metal, brush on the butter, and heat the base material evenly until it flows in. DO NOT heat the butter, or you will not get a decent bond. Think of it like sweating copper pipe.
You will need a ladle to melt the bearing metal, a heat source, and some wooden sticks to stir/flux the melt. Heating is finicky, as the metal will be ruined if you overheat it (components will vaporize out) or heat it too long (components will oxidize). Heat until it melts and no hotter. There should be little dross. Pitchy pine or spruce is good for stirring, as the pitch fluxes the melt, and the wood will char, but not burn, at the appropriate temperature for most of the common alloys. We use a plumber's burner on a propane tank to melt, like used for pouring lead pipe joints. They are still available, but may not be easy to find.
Before pouring, the form (shaft or mandrel) should be smoked to reduce the chance of the metal sticking to it, and the base should be heated to just about the melt temp of the bearing metal to prevent the pour from freezing before fully filling. Too cool, there will be cold laps and/or incomplete fill. Too hot, the pour will run back out. Openings will need to be packed with dum-dum putty (linseed oil and ground up hemp rope makes a good putty. You can also buy it) to hold the metal in, or TIGHT wooden dams need to be fit. Either way, you need to secure the dams or putty in place. Be sure that you have it set up so the pour will funnel in properly. If you are pouring on the shaft that will run on the bearing, there are a number of options: pour a sleeve (shrinkage provides the oil clearance), or, if the housing is split, separate the housing with a spacer before pouring. After the pour, you can scrape the bearing for the appropriate clearance if needed, as well as cut any needed oil grooves.
Selecting the metal can be a challenge, but there aren't a lot of options pre-alloyed these days. For guidance, you can look at an older Machinery's. For oil groove guidance, an older Marks' (7th edition has a good section).
When you pour, POUR. Don't dabble. The material will shrink, so keep pouring even when you think you are done. As you pour, be sure to skim any dross.
Take a look at http://www.metalwebnews.org/ftp/bearing-book.pdf
and http://www.archive.org/details/machinerysrefer00unkngoog (see #11- bearings)
usmcpop
06-12-2010, 09:47 AM
Here's a source of babbitt alloy: http://www.rotometals.com/Babbit-Bearing-Alloys-s/2.htm
whateg0
06-12-2010, 10:40 AM
There is a reason it is a lost art. There are a lot better processes available today. Can you use pillow blocks and nylon or brass bushings?
There are better processes available for new construction, but for restoring or maintaining old equipment, babbitt may be the only practical solution. I'll try to find the link, but there's a pretty good article on restoration of a windmill that shows it being done. They have tried ball bearings and roller bearings in old windmills and nobody seems to be able to make them last, so everybody goes back to babbitt.
Dave
whateg0
06-12-2010, 10:44 AM
This might be an interesting read...
Click on the link on this page
http://www.metalwebnews.com/howto/babbitt/babbitt.html
(I linked to the parent page so those providing it can get their credit.
Dav
Pangea
06-12-2010, 12:50 PM
Thanks Guys! The wealth of knowledge on this site is fantastic! I believe that even this old coonazz can pour a babbitt bearing with these instructions and links.
usmcpop
06-12-2010, 01:02 PM
You can also go to Google books and search. Just do an advanced search with Full View Only and you will find old books with a lot of info. Try babbitt bearings or pouring babbitt.
Thurman
06-15-2010, 12:46 PM
In September of 1967 I was 18 yrs. old and got my first "real" job as a helper in the maintenance department of a local textile mill. This mill had some really old equipment brought here in 1949 from a mill in N.J. One of the first jobs I assisted the maintenance guys on was pouring multiple babbit bearings on a machine which was probably 45 feet long. Old cast iron framing with babbit bearings, quite some machinery back then. We also poured babbit bearings for two (2) very old, huge, Worthington air compressors. That was where I learned how to scrape-in the bearings after pouring. "enlpck's" description sounds as close as I can remember this being done, with one exception-all the guys I worked with back then wore overall's, all of them. I really miss and appreciate those old coots. David
slagmeister
06-16-2010, 09:22 AM
Old Woodworking Machines has a video and several links on the 'how to' Here is the link to the site http://www.owwm.org/ The DIY is located in the discussion forums- you will have to join (free) to search effectively and view.
I took a look around trying to find the link to the video but can;t place it immediately. It is there, watched it last fall.
Hope this helps;
Slag
Rbeckett
06-22-2010, 04:36 AM
Hey pangea, the procedure Enlpc is describing is dead nuts on the money. We had a guy come out when I was at the wood mill and pour in our blades and bed em on the shaver and he did it exactly as described above. Even used the wood stir stick for flux. The guy was eccentric, but got the job done pretty quick and they lasted a good while when bedded that way. The flywheel on the shaver weighed about 1 1/2 tons and was spun up with a 300 HP motor and would devour a complete 40 foot tree in about 9 seconds. It was impressive to watch it work. The out feed chute was hydraulicly operated and pointed into a semi trailer about 50 feet away and it filled a whole trailer in about 10 minutes, top to bottom, front to back, packed tight. The yard jockey had a hard time keeping up with empty trailers. Babbit bearings were the new tech way back when, and they havent changed much in the years since. Good luck on your water wheel resto project.
Bob
SidecarFlip
06-22-2010, 11:13 PM
Babbit bearings are a lost art. Just ask 'if you can' the 9" South Bend Benchtop Lathe that I spent 3 years restoring (including new Babbitt headstock bearings. I use it every day. Keep 'em oiled well and they will outlast and hold a tighter tolerance (runout) than most modern spehrical or roller bearings.
First thing I do before I run it, is check the oil cups.
just a thought but a few people into vintage car restoration have the set ups to do babbitt.
I went to a seminar 3 or 4 years ago in Tennesse & watched guys at a model "A" ford restoration shop pour & machine it. on a Ford model "A" block. very finicky stuff, if base metal your pouring to has any cold spots it will spit the babbitt back, I saw it spit 10 feet in air & I had some land on my leather coat & I was 15 feet back. there were using a cutting torch for heating just to be more portable, where they needed a rosebud or a furnace to really heat the block first, & then at least temp melting crayons, they were just taking a surface reading, but for the demonstration it was very interesting, it was put on by a great guy with a great heart, just to pass on the knowledge, around 80 people came to his seminar & he provided free food, & soda, plus put the seminar on for free! unfortunately I did miss a little of the actual prep work, as they were also putting on a sheet metal classes & their main welder was out sick & he asked everyone if anyone knew how to weld, & I said yes, with cars, & I ended up helping some in there trying to show people how to weld sheet metal. I was offered a job, but wasnt interested in a permanent move.
anyway the babbitt tools, there were large tool kits, big heavy long wooden boxes that housed all the tools. finding someone that has one & getting him to do it may be simplier? from my understanding the kits were universal, & would allow you to set up for nearly anything & probably 8+ feet across & then line bore it with either a drill or hand powered crank. some guy here in my town has one, but he went & joined the military to help fight & I havent heard from him since. he worked at a local machine shop doing car engine machining.
the local guy said he did say he cut the bearings most of the time to use insert bearings instead of pouring babbitt, but would do whatever the customer wanted.
Later,
Randy
usmcpop
07-11-2010, 09:02 AM
Folks, do be careful if you use an intense heat source. You don't want to be breathing any fumes of stuff that may vaporize, like lead!