A J 602 repour- Part 1
Post by windybob » Fri Aug 29, 2025 10:32 am
How I Poured Babbitt in my 602 by A.J. Wodack -May, 2003
DISCLAIMER
This article is how I poured babbitt in my Aermotor 602A project, and NOT on the proper way to pour babbitt. This article is not intended as an instruction instrument to pour babbitt. I am not an instructor nor qualified in the instruction of pouring babbitt. There are much more qualified people out there than I, that can give this instruction.
Babbitt by it very nature is a hazardous material. Once heated to it's working state of 500 degrees plus, becomes much more of a hazard. Not only by the fumes it produces, but in it's molten state can splatter, or even explode, causing severe injuries to a person.
My advice to you..... Don't try this at home!! Contact a professional windmiller to pour your babbitt for you.
The Project
As you may recall in a previous article, the "Armel Experiment", where I placed roller bearings in the snoot of the windmill in place of the original stock babbitt bearings. Due to alignment problems with the shaft and bearings, the oil seal failed. Thus, precipitated the replacement of the original babbitt bearings. Some viewers out there wanted to see how I did it, so here goes......
Limitations
Please keep in mind, I've only done a few 602s, I feel the information given here on the 602 is fairly accurate. My process of pouring babbitt is a continues adaptation and experimentation. And because I'm a 'trial and error' type person, I've been known to do things many times over until I'm personally satisfied.
Jigs, Jigs, and More Jigs
I've made a number of jigs to do my babbitt pours. It sure makes my life much easier, though one can do it without the jigs, it's just a little harder to do.
First up is my windmill engine stand. I can turn the mill motor in any direction, at most any angle, a real plus when it comes to pouring babbitt. Being by myself, its like an extra hand or two.
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One of many tilts by my engine stand jig. When doing the middle bearing the snoot needs to be almost straight up. With the front bearing the snoot needs to be almost staight down.
Next is my stainless steel mandrel, stainless is a bit tougher, so it resists dings and scratches. Plus it doesn't rust. I have a built in centering lip on the front, notches cut on each side so I can fit a 1 1/8 inch open end wrench to turn the shaft. A drilled and tapped hole on the same end so I can screw in my slide hammer into it for easier pulling after the pour. A 3/8 inch bolt hole on the opposite end of the shaft, used for centering the shaft on the 602 models that has the rear saddle bearing plug. (If the 602 model doesn't have this plug, then the bolt is removed and other centering schemes are used.) The main shaft diameter is .996 + or - .001.
Use an electric hot plate to warm up the mandrel before the pour. Don't worry....The paper won't catch fire during the pour.
aj32.jpg
Boss bearing jig is nothing more than a boss gear set that was broken beyond use. I trimmed off the gear part, and used a nut and bolt to hold the journal together. A couple of slits were cut into the side of the bearing journal, and 20 ga tin was used as seats that slid into these slits. The tin piece closest to the hub shaft side of the mill was cut at a half inch, and also used as a centering guide for the main bearing journal. The other tin seat has a 3/8 inch pour hole in it's center, and is expendable. Generally after the pour I use a chisel to knock off the overflow babbitt, and it (the tin seat) can become a bit bent after that, and a new one is made.
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If you use a simple jig to hold the boss
bearing jig a much finer centering
adjustment can be achieved.
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Homemade pitman arm babbit
pouring jigs.
Last is the pitman arm bearing jigs, these too were made from stainless steel stock. These are zero clearance jigs, meaning I have a .002 oversized clearance already built into the jig. As a separating agent I use WD-40 on these.
Separating Agents
As long as separating agents was mentioned...... Something is needed to break the bond between the babbitt and it's mold or mandrel. A lot of different things can be used, and it's going to boil down to what your most successful with, on what you use. It's personal preference thing.
A few that I've use..... WD-40, sheetrock powder, clay dust, a rich acetylene mixture for smoke, soap stone, paper, and tape. I'm sure there are many more items out there that can be used. However this list should give you an idea.
Jigging For The Pour
I spend more time jigging for a pour, than it takes to make that less than 5 second pour. Centering the mandrel is high on the agenda list. Not wanting to have a stuck shaft, on multiple pours like on this 602, I'll make each of the 3 pours separately. A separating agent is needed to keep the mandrel from sticking to the babbitt, making for an easier pull out, and clearance purposes. Damming is another consideration one has to take into account. Tilting the mainframe in the right position for the pour, and let's not forget about preheating the cast to get the moisture out.
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Doing a little preheat of the cast will draw moisture out that might otherwise interfere with the pour.
Starting my jigging for the rear saddle bearing, I already knew I was going to use a grocery store brown paper sack as my separating agent. Cutting out the length I needed, doing a tight wrap, butting the two edges together, I scotch taped it together. Using my micrometer I found my wrap gave me .004 over on my mandrel. Perfect!! (After the pour, this clearance figure will shrink a little as the babbitt shrinks from cooling.)
Prep of the rear saddle. If you can't get the paper out your torch will do the job.
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Mounting my mandrel and centering it, I lock it down with my bolt in the bearing saddle plug hole. Using Babbitt-Rite as my damming material I plug everything but the pour hole, making sure everything is sealed. Then tilting my mainframe in the position I needed for the pour.
Torches
Two kinds of torches that I used here for the preheat. When I do babbitt pours I find the Bernz-O-Matic propane hand held torch to work the best. The Oxyacetylene torch kind of gets too hot too quickly and a little harder to control the heat needed. Care must be used here. Oxyacetylene is fantastic, to melt out the babbitt on a screw up though..... I've used both, just prefer the propane one for preheat, and propane has a clean flame to boot.
Making the Pour
Preheat the cast, you'll see the moisture coming up to the surface. Because the cast is rather thick at these bearing saddles, I let the heat permeate through to the inside, saturating it as much as I can. Preheating to around 100 to 200 degrees (this is a 'guess and by golly' on my part) I'm ready for my pour. Just before doing my pour, I do a mix on my molten babbitt, then skim off the dross that forms at the top from the mixing, With the molten babbitt being bright and shiny with no floaters, I then make my pour.
aj37.jpg
A babbit melting pot on the electric hot plate. A tin spoon to clean off the dross before a pour.
Get that Mandrel Out!!
This is no time to sit back and admire the pour. You need to get your mandrel removed from your pour!! Babbitt has a bad habit of shrinking and locking the mandrel fast if left to cool for any length of time. Babbitt will solidify almost immediately after the pour, as soon as I feel confident the babbitt is solid, I knock off the damming material, remove whatever I have holding my mandrel in place, and yank that mandrel out!!
Sometimes a twist or turn of mandrel is sufficient to release it for a hand pull out, or one may need other means to push or pull the mandrel out. Having my share of problems getting things apart in the past, I built in a couple of modifications to my mandrel. Notches cut on each side so I can fit a 1 1/8 inch open end wrench, or crescent wrench to turn the shaft. I drilled and tapped a hole on the end so I can screw in my slide hammer into it. Additional modifications, included separating the rear saddle bearing mandrel, and taking an additional .005 of an inch off on nonessential section of the mandrel to give additional clearance.
Moving On
After the first pour I start jigging for my next, going through basically the same routine mentioned above, doing some slight modifications along the way. First I clean off my mandrel and buff it up with some fine steel wool. The first pour should be cool enough by this time to check to see if enough clearance was made. Test fitting the hub shaft or mandrel in my pour, satisfied with the fit, I tape up a new piece of paper on my mandrel for my next pour.
You can pour 2 at a time. WD-40 works as a seperating agent.
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Use a rasp for edge clean-up.
On the center bearing I added a 3/8 inch oil grove, made with Babbitt-Rite, down the center of my tape seam. This grove goes from the spout washer hole snoot side, to the center cavity. The 602 doesn't have an oil exit hole like on the 702, it is built into the mainframe casting. Starting about 3/4 of an inch or so from the front of the pour hole, and exiting into the mainframe along side the spout washer hole. If you don't know it's there, it can be easily missed. When damming, there is somewhat of a square hole where the spout washer goes that needs to be open. Make sure you put some Babbitt-Rite here too to keep that open.
aj39.jpg
3/8" oil groove in the middle bushing. Place it straight and on top opening in to the cavity.
When pouring this center bearing you want the snoot almost straight up. The babbitt can easily flow into the oil return hole as your pouring, plugging it up if your not careful. Thus, causing the oil to overflow from your hub when the mill is running. Make sure the oil return hole is still open after you make your pour!!
The oil return hole location is marked on the outside of the case. Note the distance between it and the pour hole. This is the reason for having the snoot almost straight up for the pour. Use a piece of wire to insure your oil drain hole remains open.
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Call Dan Benjamin for parts. P M me for the phone number. IF YOU TALK TO HIM, AND HE HELPS YOU, THEN BUY FROM HIM. IT CREATES GOOD KARMA.
A J 602 repour- Part 1
A J 602 repour- Part 1
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Call Dan Benjamin for parts. P M me for the phone number. IF YOU TALK TO HIM, AND HE HELPS YOU, THEN BUY FROM HIM. IT CREATES GOOD KARMA.
Re: A J 602 repour- Part 1
Bob , thanks for the refresh class .
Re: A J 602 repour- Part 1
Thanks guys. I had that scattered in different places in my pc. someone was aking about pouring a 602, so I took a lot of time today gathering all the stuff together and assembling it. It's odd that the pictures do NOT follow the writing when transferring it from one place to another. So I had to place thm in the text, one at a time from a file I copied from another file, cause they wouldn't transfer either. Next time my son comes up, I'll ask him about it. If anyone here tries to copy and paste the tutorial, they probably won't get the pictures, either.
Call Dan Benjamin for parts. P M me for the phone number. IF YOU TALK TO HIM, AND HE HELPS YOU, THEN BUY FROM HIM. IT CREATES GOOD KARMA.
