Subject: Re: Babbitt bearing replacement

From: [email-masked] (Mike Rehmus)
Date: 1 Dec 1994 02:04:30 GMT

In <[email-masked]> [email-masked] () 
writes: 

>
>I was given this newsgroup as a possible source of information for our 
high
>school.  Thanks for your time!
>
>"We are looking for information or suggestions on the repair or
>retrofitting of our building ventilation system which was constructed 
in
>the 1920's!  It has large shaft diameter babbitt bearings which need
>replacement and we have no known source.  Any suggestions on 
replacement of
>the bearings or conventional replacement would be most sincerely
>appreciated!"
>
>-- 
>Edee Miller, Library/Media Generalist
>Bemidji Middle School
>Bemidji, Minnesota, USA
>[email-masked]
>

I would try to contact a member of the Early Day Gas Engine & Tractor 
Association.  They always have this problem and it seems that at least 
one person in each Chapter (they are national in scope) can still pour 
babbit.  Contact the national president, Jack Versteeg at 503 393-9789 
for a contact in your area.

Best
Mike

---

From: [email-masked] ()
Date: 30 Nov 1994 16:55:47 GMT

I was given this newsgroup as a possible source of information for our high
school.  Thanks for your time!

"We are looking for information or suggestions on the repair or
retrofitting of our building ventilation system which was constructed in
the 1920's!  It has large shaft diameter babbitt bearings which need
replacement and we have no known source.  Any suggestions on replacement of
the bearings or conventional replacement would be most sincerely
appreciated!"

---

From: [email-masked] (James Kirkpatrick)
Date: 30 Nov 94 17:49:33 MST

In article <[email-masked]>, [email-masked] () writes:
|>
|>"We are looking for information or suggestions on the repair or
|>retrofitting of our building ventilation system which was constructed in
|>the 1920's!  It has large shaft diameter babbitt bearings which need
|>replacement and we have no known source.  Any suggestions on replacement of
|>the bearings or conventional replacement would be most sincerely
|>appreciated!"

According to posts earlier this year, babbit metal is available from
Centaur Forge.

   -  Centaur Forge Ltd.
      P.O. Box 340
      117 N. Spring Street
      Burlington, WI  53105
      (414) 763-9175, (414) 763-8350 (FAX)

Back on June 14 Andy Dingley posted a description of how to pour and
scrape a babbit bearing, if you're interested in replacing babbit with
babbit.  Let me know and I can pull it from the archive, or you can
pick up the archive and/or FAQ from plains.uwyo.edu in the METAL directory.

Jim

---

From: [email-masked] (Andy Dingley)
Date: Sat, 3 Dec 1994 18:18:58 +0000

In article <[email-masked]>
           [email-masked] "James Kirkpatrick" writes:

> |>replacement

> scrape a babbit bearing,

Hey !   4 months off the net, I get back a couple of days ago and the first
thing I see is a reference to one of my old postings.  I feel like Kibo  8-)

Here's my old Babbit piece:

In article <[email-masked]>
           [email-masked] "Mark Will" writes:
> Does anyone have experience pouring bearings made of babbit?  How do you do it?
> I have a need to pour a connecting rod bearing for an old Witte farm engine.

Well I thought this was an arcane skill I'd *never* get asked about on the net,
but after all there are people here who make chainmail.  8-)
Casting whitemetal bearings is easy, scraping them to fit needs slightly more
skill. I've done this for a bunch of engines now, from small stationary
(farm) engines, up to a White Scout Car (WW2 armoured car) and a 12" diameter
steam engine connecting rod big end.

   You need:

Gas/blown air torch

Flux (zinc chloride / killed spirits)

Whitemetal/babbit metal. For bearings, this can be either tin based or lead
based. The terms "whitemetal" and "Babbit" are too vague to be useful here -
buy it ready-mixed from a bearing supplier such as Glacier. It's still
available, but you have to look hard. If you have a network of farm engine
collectors, as we have in the UK, then the specialist dealers will have it in
stock. I was at a vehicle show at the weekend where sticks of it were on sale.
Older bearings are generally lead based. '40s-'50s ones are tin based and
usually thinner.

Tinning solder. This will be 50/50 lead/tin solder for most bearings. Tin
based bearings in steel shells will use pure tin. Gunmetal or bronze shells
can use 50/50.

Casting stand. This is a heavy steel fixture, to which the bearing shell is
clamped during pouring. Mine is made from a piece of L girder, with a
half-tube of scaffolding pipe welded aginst one inner face. I use a welding G
clamp to clamp the bearing shell into place, with the scaff pipe taking the
place of the crankshaft. If your bearing also has thrust faces, then you may
need C shaped metal spacers too, to lift the bearing shell off the surface of
the fixture.

   The process:

Clean up the old bearing. Scrape or file off cracked & contaminated
whitemetal, then degrease. If you can't clean the whitemetal to a perfect
surface, then heat the whole bearing up and melt off the old metal. Allow to
cool, and paint the non-tinned surfaces with whitewash.

Tin the bearing shell. This is easiest in a tinning pot, but you'll probably
need to do it by hand, with a stick of solder. Warm the bearing shell up
evenly, trying to avoid oxidising the clean surface. Dip the solder stick in
flux, and wipe it over the heated shell. Don't over-heat the tinned surface,
as you want to avoid oxidising the solder. If the bearing shell has
sufficient heat capacity, it's best to warm it up first, then do the tinning
with this residual heat alone, not using the torch directly. In some cases, a
moleskin is needed. This is a thick pad of *cotton* corduroy cloth, or denim,
dipped in flux or tallow and used to wipe the solder over the cleaned area of
the bearing until it is all bright and shiny. Using a moleskin is *not*
regarded as good practice - careful heat control is much better.

Assemble the casting fixture. The bearing should be clamped into the fixture,
sealed with a rope of asbestos putty ("Moist-bastos" brand welder's
heat-shielding putty works). There should be sufficient clearance between the
bearing and the fixture to have enough bearing metal to allow machining and
fitting. Custom fixtures are not unusual. Before assembling the bearing shell
into the fixture, the fixture should be pre-heated to 200-250 oC.

Pour the bearing metal. Melt temperature should be as recommended by the
bearing metal maker, although 450 oC is a reasonable maximum. I use a
thermocouple to measure this, although there are also craft techniques
involving the time it takes squares of newspaper and stale bread to catch
fire 8-) Before pouring, flux the surface of the melt and skim off the dross.
Pour the melt in *one* swift operation (Important !). As it cools, the melt
will contract noticably - especially for lead based melts. If you don't have
enough pouring space to allow for this, then you *might* need to pour in a
little more metal.

If you have problems with trapped air in the shells (almost certainly) then
you'll need to either increase the spacing between the bearing shell and the
casting fixture, or use a puddling wire (thin welding rod) to work the still
molten melt gently up and down and allow the air bubbles out. You should be
able to feel the melt gradually solidifying from the bottom of the shell
upwards.

Once the bearing is poured, then it's a good idea to gently cool the *back*
of the bearing shell. This improves the adhesion between shell & bearing. Use
a damp cloth, or water-filled plant sprayer, from the bottom upwards.

Now the bad news - the bearing should really be metalled by tinning it,
assembling it into the fixture, and pouring the metal, all in one smooth
operation -- before the tinning solder has solidified ! Practice with it
cold, have everything ready, and have an assistant to do the clamps up.

If your bearing doesn't look right, melt it off and try again. Your first
couple probably won't be usable, so don't be surprised. Don't use a badly
cast bearing, it isn't worth the trouble. Don't re-use contaminated bearing
metal.

Once you're happy with the casting, you'll need to machine the bearings to
size, and then scrape them to a final fit. I'll leave someone else to
describe this bit  8-)

--
Andy Dingley                             [email-masked]

No, I wasn't abducted by Space Aliens - I've been in the Mid-West for 
a few months and couldn't get decent net.access.

---

From: john nichols jn493 <[email-masked]>
Date: Thu, 15 DEC 94 20:45:12 -0500

Babbitt bearings are alive and well and are still being used.
You have to know if you have low or high speed babbitt bearings.
The bearings have to be re-poured and machined to size. This
is a common thing. There is no problem in getting this done.
If you have a good shop, you can do it or send it out.