Before ball bearings, ceramic bearings and modern bearings gained popularity, Babbitt bearings were the common bearing used when precision and longevity was essential. Made from an alloy of tin, antimony and lead, in most cases, the bearings were used in everything from the original Ford Model A and Model T to the massive vertical turbines of the Hoover Dam. In the 1940s, nearly any metal works or machine shop featured at least one Babbitt bearing repair specialist. While Babbitt bearings are less common these days, they still see regular use in applications involving heavy objects or constant, slow movement.
One of the most important components of any Babbitt bearing configuration is lubrication. Without lubrication, the soft Babbitt bearing material can be damaged, warped or worn away. When this happens, the shaft or journal supported by the journal bearing can lose accuracy. In extreme cases, the bearing can fail completely. This could potentially damage the machine and cost thousands of dollars to repair.
Most Babbitt bearings are custom poured for each device or application. While this provides an exceptional fit and outstanding anti-friction benefits, it tends to make Babbitt bearing pricey. Major manufacturers of Babbitt bearings include:
- Babbitt Bearings Incorporated
- PME Babbitt Bearings
- Odessa Babbitt Bearing Company
Costs can be alleviated by learning the skills for pouring Babbitt bearings yourself. However, this is something that should be done with utmost caution and attention to safety. While different Babbitt alloys will behave differently, the steps for pouring any Babbitt bearing is fairly similar. These tips are a general guideline. For specific information, contact the maker of your Babbitt alloy, a machinist or a metalworker. Failure to properly handle and pour Babbitt can result in serious injuries.
- Heat and clean your journal casing. All preexisting Babbitt should be cleaned from the surface prior to pouring a new Babbitt bearing. This is best done with a furnace and Babbitt scraper. If Babbitt comes in contact with cold metal, it can explode violently. This can create serious burns and cause lead poisoning. A surface with texture is ideal as this creates a better bond.
- Heat your Babbitt using an electrical heater or other controlled heat source. Overheating Babbitt can be very dangerous. If the Babbitt being used contains lead, the lead can vaporize and poison anyone in the vicinity.
- When you have reached the proper temperature for your Babbitt, you should skim the dross from the heating container. In most cases this can be done easily. Failure to remove the dross will result in a weakened Babbitt bearing and can cause poor formation and premature failure.
- Once all dross is removed, you can begin the pouring process. Using a ladle is an ideal way to pour Babbitt. Pouring should be done quickly and in one motion if at all possible. Pouring too slowly can result in a poor bond and sub-par performance in the final piece.
- Allow the Babbitt bearings to fully cure and harden before use.
- Lubricate the Babbitt bearings and test for quality.