Instructions for Pouring Bearings

Instructions for Pouring Bearings

The babbitt in a perfect bearing must be poured to form a dense, solid mass, and must adhere firmly to the bearing shell so that no oil can penetrate between the liner and the shell. When a firm bond is not secured between babbitt and shell, oil leaks in and hydrostatic pressures are set up which often force the babbitt completely away from the shell, allowing the babbitt to vibrate and finally crumble. To assure long-life bearings, select the proper babitt and pour your bearings as follows:

1. CLEAN THE BEARING SHELL- Remove foundry scale, dirt or rust with grinding wheel, sand blast, file, wire brush, or by chipping. Remove all oil or grease, either by burning or by scouring with hot caustic solution. (If caustic is used, rinse thoroughly with hot water.)

2. HEAT THE BEARING SHELL- If the shell has been heated to remove oil, no further heating may be needed. Otherwise, heat to about 500?F., being careful to heat evenly. Remove any soot with wire brush.

3. APPLY FLUX- Apply flux to the surface of the bearing shell and immediately rub with a bar of Tin or 50/50 Solder. Work as fast as possible--use flux liberally. As soon as each area has been covered with tin or solder and while the shell is still hot, scrub the surface with a soft wire brush. This bonds the tinning material to the bearing shell.

4. AFTER TINNING IS COMPLETED-While still hot, wipe surplus flux and tinning alloy from surface with a woolen cloth.

5. FASTEN JIG--CAULK JOINTS

6. STIR BABBITT-To ensure uniform temperature throughout, stir the metal thoroughly from bottom to top. Skim dross from surface.

7. USE LARGE LADLE-If possible, use a ladle large enough to pour the entire bearing at one dipping. If not possible, use two ladles, pouring simultaneously. Immerse ladles in babbitt pit for five minutes before pouring, to properly heat them.

8. POUR SLOWLY AND EVENLY

9. CONTINUE TO ADD BABITT- As the babbitt begins to shrink down into the bearing, continue to add molten metal to prevent formation of shrinks and to assure a denser mass. Pouring temperatures listed in the descriptions are subject to variation depending on size of bearing and temperature of bearing shell.