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Babbitt Re-pour Questions

M.B. Naegle

Diamond
Joined
Feb 7, 2011
Location
Conroe, TX USA
I'm gathering all the bits and pieces to pour some Babbitt for a couple projects and I had a couple questions.

Project #1 is a couple of Babbitt lined bearings for some overhead shafting hangers that I'll be using to power my Whitcomb Blaisdell lathe. The info on the web and a few old books I have makes it seem fairly straight forward, however most every example I've seen they used the actual shaft and other parts to hold everything square in the machine itself. In my case, overhead shafting is fairly long and cumbersome to move around, so I plan to just use a short drop that is the same diameter and make some kind of spacers that will hold it in the center of the cast iron shells that encase the Babbitt. The cast iron shells have no machined surfaces on them and are the kind that have oiler rings inside so I'll also need to create a couple of voids in the top caps for the rings. Each bearing has the two halves, as well as a lower reservoir shell. Do you guys have any tips for bearing of this style? Do they need to be scraped afterward (how?) and how elaborate should I get with oil grooves? It doesn't look like they had them before.
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I'll re-use the existing Babbitt, and I have a couple new ingots to add to it. I also just got a pound of Rotometal casting putty to dam everything in, and a cup of tinning paste to help the Babbitt bond to the iron.

Project #2 is the half-nuts for my 1909 Hendey 16" lathe. The original Babbitt is gone and instead a prior owner made a set of bronze inserts and pinned them to the half-nut shells. Only one side of the bronze is still there and it was very worn, so I cut it out and cleaned the cast iron shells and am going back to the old Babbitt system. Similar to the bearing project, the only half-nut re-pour examples I'm aware of use an un-worn portion of the machines lead screw for the center core. My lead screw is long and difficult to move around and has a key-way cut through one side, so I'm thinking about threading a short piece of round stock (without the key-way) to match a virgin portion of the lead screw and making a fixture that will hold it squarely in the center of the half-nuts. I might only need to use it once every 50 years, but I think it would be easier than a make-shift arrangement.
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Anything else I should be aware of with these two cases? I know about using acetylene smoke as a release agent on the shaft/screw section, and I should pour the bearings one half at a time. Now that I have the ingredients to pour the Babbitt, I need to make the fixture to hold the half-nuts and a piece to do the bearings with. I'll post my progress as it comes.
 
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I taught a scraping class at American Babbitt a few years back on how to scrape Babbitt. I wrote them this morning and here is what my friend Nick wrote back:

Dear Nick,

There is a fellow on Practical Machinist who is a student and friend who wants to re-babbitt his bearings. I was thinking you could possibly help him out on PM. Or I could give him your name and post it on Practical Machinist and he could call you? He is a small manufacturing plant it Texas and they have several old machines. Maybe some info on "how too" and just not saying send it to us...
_______________________________________________
Richard,
Good morning and great to hear from you. I would be happy to assist, please tell him to reach out to me so I can better understand what he is trying to accomplish.

The best way to contact me is email or cell phone.
My Best
Nick
Nick Smith
Sales Manager / Project Manager
American Babbitt Bearing
80 Industrial Lane
Huntington, WV 25702
Mobile: (304) 412-4120
[email protected]

Industrial Babbitt Bearings Repair Manufacture Services | American Babbitt Bearing
 
Thanks for the leads.

I got a head start on making the lead-screw core for the half-nuts last night. After measuring my screw I custom ground a HSS cutter with 10 degree angles and ground the face to match the minor diameter. I got about 80% done before I blew up the cutter... so I'll need to start over re-grinding the form and clock the blank in the chuck to finish it off. It was my first time single-pointing an acme thread, so I don't feel too bad about it. I think I tried to take too much off in one pass and didn't have enough relief.
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I thought about getting in touch with Hendeyman to get the actual lead screw dimensions, but I figured If I was half a degree off on my cutter grind, the Babbitt would wear in once in use. I measured it as a 1 1/4-6 screw with a minor diameter of 1.038.
 
Rather than grind the cutter to match the full width of the thread, you might want to grind it narrower (compound set to 90°) then move the tool slightly left and right to get to your finished thread width. Use thread wires to measure and finish the thread to the same pitch diameter as your lead screw.
 
Rather than grind the cutter to match the full width of the thread, you might want to grind it narrower (compound set to 90°) then move the tool slightly left and right to get to your finished thread width. Use thread wires to measure and finish the thread to the same pitch diameter as your lead screw.

I had the compound set at 9 degrees to feed in similar to single pointing a 60 degree thread, but I suppose that with such a steep angle, there isn't much advantage to it so a straight in feed would be better.
 
Much of that is dependent on your lathe and its rigidity. On a small machine or even a large thread on a big machine you are probably better off going straight in a little bit then widening left and right. Straight in a little more, widening left and right. Etc. Etc.
 
Much of that is dependent on your lathe and its rigidity. On a small machine or even a large thread on a big machine you are probably better off going straight in a little bit then widening left and right. Straight in a little more, widening left and right. Etc. Etc.

I'm cutting it on our South Bend Heavy 10, so not a lot of power. I'll try the approach you've described.
 
I'm gathering all the bits and pieces to pour some Babbitt for a couple projects and I had a couple questions.

Anything else I should be aware of with these two cases? I know about using acetylene smoke as a release agent on the shaft/screw section, and I should pour the bearings one half at a time. Now that I have the ingredients to pour the Babbitt, I need to make the fixture to hold the half-nuts and a piece to do the bearings with. I'll post my progress as it comes.

There are 10 different types of babbitt in general use. Five of them are tin based and the remainder are lead based. Unless you know what the original babbitt specification is you cannot mix the old recycled babbitt with the new.
The improvised mixture will fail.

The old babbitt needs to be melted out while carefully retaining the tin base layer. It is difficult to effectively tin oil soaked cast iron.
When you pour the babbitt the shell and core need to be preheated to insure that the tin layer is molten and to prevent a fast freeze of the babbitt to the steel mandrel. Once the pour has been made the shell needs to be cooled immediately with a air or water spray. This will insure that the babbitt cools from the shell outward to the mandrel. The goal is to prevent the babbitt from shrinking and pulling away from the shell. You want the babbitt to shrink and pull away from the mandrel. The other goals of a fast freeze are to prevent the babbitt alloy components from segregating and to prevent large grain growth in the babbitt.

Make sure that there is a sufficient gap between the shell and mandrel to allow the babbitt to be poured without voids. There needs to be a vent for trapped air to escape. and there needs to be a molten metal reservoir to insure that there is no shrinkage void at the top of the pour. It may be necessary to use a reduced diameter mandrel to make a void free casting and then bore out the casting to match the shaft diameter.

Each babbitt alloy has a optimal temperature for pouring. A immersion thermocouple plugged into a inexpensive volt meter will be helpful in achieving a good casting on the first try.

This PDF will fill in all the details of what was outlined above:

https://www.maintenance.org/fileSen...0942964861958/Fry_Babbitt_Reference_Guide.pdf

There is a inexpensive bottom pour electrically heated cast iron pot that is sold to the bullet reloaders that will make this job easier. Its only drawback is that the cast iron pot is not compatible with tin based babbitts.The tin will slowly erode the cast iron. For a one time use it should not be a problem provided that the left over babbitt in the pot is not reused.

There is a ceramic paint available in a pint sized can that can be used to line the pot. Some of the vendors sell the pot already painted for a additional cost.

Buy Ceramic Coating - ITC 100 Refractory — ITC Coatings
 
There are 10 different types of babbitt in general use. Five of them are tin based and the remainder are lead based. Unless you know what the original babbitt specification is you cannot mix the old recycled babbitt with the new.
The improvised mixture will fail.

The old babbitt needs to be melted out while carefully retaining the tin base layer. It is difficult to effectively tin oil soaked cast iron.
When you pour the babbitt the shell and core need to be preheated to insure that the tin layer is molten and to prevent a fast freeze of the babbitt to the steel mandrel. Once the pour has been made the shell needs to be cooled immediately with a air or water spray. This will insure that the babbitt cools from the shell outward to the mandrel. The goal is to prevent the babbitt from shrinking and pulling away from the shell. You want the babbitt to shrink and pull away from the mandrel. The other goals of a fast freeze are to prevent the babbitt alloy components from segregating and to prevent large grain growth in the babbitt.

Make sure that there is a sufficient gap between the shell and mandrel to allow the babbitt to be poured without voids. There needs to be a vent for trapped air to escape. and there needs to be a molten metal reservoir to insure that there is no shrinkage void at the top of the pour. It may be necessary to use a reduced diameter mandrel to make a void free casting and then bore out the casting to match the shaft diameter.

Each babbitt alloy has a optimal temperature for pouring. A immersion thermocouple plugged into a inexpensive volt meter will be helpful in achieving a good casting on the first try.

This PDF will fill in all the details of what was outlined above:

https://www.maintenance.org/fileSen...0942964861958/Fry_Babbitt_Reference_Guide.pdf

There is a inexpensive bottom pour electrically heated cast iron pot that is sold to the bullet reloaders that will make this job easier. Its only drawback is that the cast iron pot is not compatible with tin based babbitts.The tin will slowly erode the cast iron. For a one time use it should not be a problem provided that the left over babbitt in the pot is not reused.

There is a ceramic paint available in a pint sized can that can be used to line the pot. Some of the vendors sell the pot already painted for a additional cost.

Buy Ceramic Coating - ITC 100 Refractory — ITC Coatings

Thanks! That's a lot of good insight. I'll be sure to keep the old Babbitt out of the mix. We had a lot of random lead bits that I melted together awhile back, some might have been Babbitt, but it comes in handy for making weights or other cheap-white-metal jobs. We have a couple of cast iron lead pots and ladles that should be fine for these jobs, but giving them a ceramic coating sounds like a good idea. I also have a very old white gas stove that was made for lead work, but it needs to be restored so I'll likely just use one of our heat-treating ovens for all of the pre-heating and melting, and the oxyacetylene torch for any thing else.
 
I need to get some pictures up, but I practiced a little pouring the Babbitt in the bearings tonight. Did two pours on the same bearing half and neither will be usable, but it was good practice.

Couple of thoughts: I'm going to get a clean flat sheet of metal and a little cup of water for forming the damming putty. I didn't have any Babbitt spill-out accidents, but 90% of my problems seem to be getting the putty right where it's needed as I either get too much in one spot that seeps into where I want the Babbitt, or not enough and have to carve it out. I'd rather have too much Babbitt, but I'm thinking if I'm more exact rolling out the little logs of putty then just rolling it in my hands, I'll get more consistent edges. The water would be to help keep it from sticking to the rolling plate, like flour and bread dough.

My first attempt, I tried to pre-heat the iron with the torch after I had dammed everything in. This didn't work well as the putty burns and the flux didn't coat the iron well enough. On the second attempt, brushing the flux on hot iron worked much better and even though it wasn't as easy to work with, I still had plenty of time to set all the putty in place after preheating and fluxing the iron.

One other thing I'm finding is that the Babbitt cavities are so thin, I'm having trouble controlling how the Babbitt pours in and it's sealing up the cavity before the whole thing is full. I'm using a 1-cup sized lead ladle and I'm probably pouring a little too slowly, but I'm thinking about trying my lead bullet ladle as it has a smaller spout and might be easier to control the pour.

This stuff seems to all be basic metal casting and lead working principles, but I'll get it figured out.:crazy:
 
I need to get some pictures up, but I practiced a little pouring the Babbitt in the bearings tonight. Did two pours on the same bearing half and neither will be usable, but it was good practice.

Couple of thoughts: I'm going to get a clean flat sheet of metal and a little cup of water for forming the damming putty. I didn't have any Babbitt spill-out accidents, but 90% of my problems seem to be getting the putty right where it's needed as I either get too much in one spot that seeps into where I want the Babbitt, or not enough and have to carve it out. I'd rather have too much Babbitt, but I'm thinking if I'm more exact rolling out the little logs of putty then just rolling it in my hands, I'll get more consistent edges. The water would be to help keep it from sticking to the rolling plate, like flour and bread dough.

My first attempt, I tried to pre-heat the iron with the torch after I had dammed everything in. This didn't work well as the putty burns and the flux didn't coat the iron well enough. On the second attempt, brushing the flux on hot iron worked much better and even though it wasn't as easy to work with, I still had plenty of time to set all the putty in place after preheating and fluxing the iron.

One other thing I'm finding is that the Babbitt cavities are so thin, I'm having trouble controlling how the Babbitt pours in and it's sealing up the cavity before the whole thing is full. I'm using a 1-cup sized lead ladle and I'm probably pouring a little too slowly, but I'm thinking about trying my lead bullet ladle as it has a smaller spout and might be easier to control the pour.

This stuff seems to all be basic metal casting and lead working principles, but I'll get it figured out.:crazy:

There used to be a product called Babbitrite that contained asbestos. In the form of the damming paste as it was supplied it almost certainly produced no measurable level of airborn asbestos. But since it contained asbestos it is no longer made. Reportedly old stock can be found. However a new product is available Deacon Mold-Pac (Babbitrite Replacement)

RotoMetals Casting Retainer Putty 1 Pound Great for Damming/Molding/Positioning -Made in USA: Automotive Adhesives And Sealants: Amazon.com: Industrial & Scientific

Not heat sensitive.

Denis
 
There used to be a product called Babbitrite that contained asbestos. In the form of the damming paste as it was supplied it almost certainly produced no measurable level of airborn asbestos. But since it contained asbestos it is no longer made. Reportedly old stock can be found. However a new product is available Deacon Mold-Pac (Babbitrite Replacement)

RotoMetals Casting Retainer Putty 1 Pound Great for Damming/Molding/Positioning -Made in USA: Automotive Adhesives And Sealants: Amazon.com: Industrial & Scientific

Not heat sensitive.

Denis

Pretty sure that is what I bought. The fibers and the putty catch a little when exposed to an open flame. Not enough to ruin it or anything, as I just blew it out and rolled it back together with a little water for the next try, but probably not meant to be taking a torch to it. It works fine with heat as it should.
 
Pretty sure that is what I bought. The fibers and the putty catch a little when exposed to an open flame. Not enough to ruin it or anything, as I just blew it out and rolled it back together with a little water for the next try, but probably not meant to be taking a torch to it. It works fine with heat as it should.

Sorry, when you were describing “putty” it was unclear to me as to what you were using. Just trying to be helpful.

Denis
 
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I thought this was interesting. The castings have some dimples cast into them to help retain the Babbitt. A prior millwright somehow fixed small tacks and brads into the dimples to help. Not sure how they did this, perhaps silver-solder or some kind of primative epoxy? Melting out the old Babbitt hasn't effected the adhesive. I don't think it's cast into the iron or original, as these bearings came from an old leather shop and the nails and brads are common leather hardware. I'm keeping them in there either way, just making sure they're bent down far enough to be under the surface of the Babbitt.
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First pour mock-up. Tried this orientation as it seemed like it would need less putty, but the bearing sides have less opening so I spilled more.
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Here's the charred putty from the first pour.
 
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Results of the first pour. No problems sticking to the shaft. The acetylene soot worked fine, but you can see where the putty flowed too far over when pressed onto the shaft. The flux also didn't work correctly as the iron wasn't hot enough, so the Babbitt chipped away from the iron when I tried to shave the overflow drips down.
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Here's the second pour mock-up. This orientation needed more putty to seal the edges, but the sprue in the iron (which I had plugged for the first pour) gives more room to pour the iron in (almost like it was MADE for this!:dunce:). The flux adhered better this time and the and the Babbitt stuck to the iron as it should, but cooled off too fast and sealed up the cavity prematurely leaving voids. If I can control the pour a little better, keep the iron hot while pouring, and get the putty in place with cleaner lines, I think the third time will be the charm.
 
I've never worked with Babbitt metal or something similar, so can't help with that.

But I do have a good amount of experience in "trying something new to me" and think that the approach that you are following here, to experiment and try out the pouring on a small scale, is exactly right. The experts here will keep giving you pointers and tips, but at the end of the day, it's your own experience that matters, since you're the one doing it. Just keep trying different pours, fluxing methods, damming techniques, and heating approaches until you find a combination that consistently does what you want. Then move on to doing it "for real".
 
This is a long shot, but you might try sending an email or PM to Forrest Addy. I can't remember for sure if I've heard him talk about babbitt repairs, but he's certainly worked on machines and parts from the era when it was more common.
 








 
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