How to Make a Babbitt Bearing

Create the Babbitt alloy by melting nine parts tin and one part copper in a melting pot at 460 degrees Fahrenheit. Skim any impurities off the top of the melted metal to keep the alloy pure.

Take off the top of the bearing shell, and position the bottom half on a flame and burn-resistant work surface. Torch the interior of the shell to completely remove any impurities.

Place a strip of damming putty on either end of the bearing shell, making sure that it covers the interior curvature completely. This will prevent any metal from spilling out during the pouring process.

Torch the portion of the crankshaft that fits into the bearing with an oxyacetylene torch until the exterior is coated with soot. The soot coating will prevent the crankshaft and molten Babbitt from sticking together. Firmly position the crankshaft inside the bearing shell so that there is a consistent gap between the two, and the damming putty completely seals off the ends.

Put on heat-resistant gloves and an apron. Pour the molten alloy into the gap between the crankshaft and the bearing shell with a cast iron ladle until the molten alloy reaches the top. Allow the alloy to cool and solidify.

Remove the crankshaft from the bearing shell by lightly hammering the shell while holding the crankshaft. Set the crankshaft aside, and remove the damming putty from the bearing shell.

Position the bearing shell on the work table of a milling machine. Use an end mill tool to remove the excess alloy from the top of the bearing shell, so that the tops of both sides are flat.

Lay cardboard strips over the entire surface of the flat areas on each side of the bearing shell. Torch the crankshaft as described in Step 4, and place it inside the bottom half of the bearing shell. Torch the top half of the shell as described in Step 2, and position it directly over the bottom half, making sure that the two are perfectly aligned.

Pack the gap on either end of the bearing shell with damming putty, making sure that the seal is airtight. Put on gloves and an apron, and pour more molten alloy through the hole on the top half of the shell. Let it sit until the alloy is cool and solidified.

Lift off the top half of the bearing shell, and remove the crankshaft, along with the remaining damming putty and cardboard strips. Lubricate the interior of each half, and reassemble the bearing shell with the crankshaft in place.