shaft log with dripless seals for centurion boat

Duramax uses an oil-impregnated nylon bearing while Nautical Specialties and PYI incorporate a carbon-graphite bearing. Three companies manufacture face seals of this type: Duramax, Nautical Specialties, and PYI. A hose connects the fixed bearing to the stern tube. A thin film of water forms on the interface between the stainless and the carbon, lubricating the seal. Often referred to as dripless, face seals compress a fixed bearing against a collar that is attached to the shaft. If you carry a small amount of replacement packing with you, it can be repacked without hauling the boat or replacing any components. The damp and salty environment can also lead to crusty buildup on the adjustable parts, and it is good practice to keep them clean and lubricated.Ĭonventional stuffing boxes offer several advantages: they are durable, reliable, field-serviceable, and simple. Maintenance requirements for stuffing boxes are minimal: monitor the temperature and drip rate, inspect the hose for cracks or dryness, and the tension and condition of the hose clamps.

This issue applies to all of the seals and will be addressed again at the conclusion. In cases where water flow is inadequate, water must be injected. The amount of water that reaches the packing gland varies quite a bit, and in some cases the conditions might create a vacuum. Keep in mind the varied configurations of boats: length of the stern tube, depth below the waterline, speed of the boat, and water flow past the end of the tube. What is an acceptable drip rate? Realistically, you will most likely have to live with about four to six drips a minute at cruising speed. A spring compresses the bearing against the seal, eliminating the need for a bellows-style hose.

Shaft log with dripless seals for centurion boat