Pouring white metal Babbitt Bearings for a Tangye steam engine

The" big end" bearings of a Tangye steam engine need rebuilding as the parts were actually missing. (See index below). At this stage we are pouring new white metal bearing surfaces. This is done without the crankshaft in place in this case, and it will be necessary to bore the inside diameter of the bearing on a lathe and this required a special jig to mount them on the lathe.
White metal contains mostly tin with only about 5% lead plus addition of copper, antimony and bismuth in various proportions. The harder copper and antimony crystals "float" in the softer tin matrix and as the tin wears and molds itself to the shaft it leaves microscopic channels for oil to flow through, while the harder crystals support the shaft.
The large surface area contacting the shaft means that the pressures between the surfaces are much lower than those seen with ball or roller bearings.
This is the second of two single-cylinder double-acting steam engines powering a large ten-head stamper battery at "The Goldmine Experience" in Thames, New Zealand. Bear with me for a few seconds at the beginning when I show the location of the engine.
Index to Pouring white metal
0:05 Goldmine experience
0:50 Melting the white metal
1:00 Pre-heating the bearing
1:55 Note in the background the piston and blank for making rings
2:24 Pouring the metal
3:00 Topping up to compensate for contraction of cooling metal
3:30 Cracking open the “mould”
3:55 Melting metal out of oil galleries
4:40 Milling offf surplus metal
5:10 Re-assembing the bearing
5:28 The jig mounted in a four jaw chuck
5:50 The complete bearing is ready for boring in the lathe
6:00 The End.
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