Securing stern tube bearings (which support the propeller shaft as it passes through the hull) is a mission-critical, high-load, safety-demanding application in marine vessels. This joint is subjected to massive and constant radial load(shaft/propeller weight), high axial thrust (propeller force), significant vibration, and continuous exposure to the marine environment (saltwater, oil/lubricants).
The bearing must be rigidly secured within the stern tube to prevent any movement (spin or walk) that would lead to fretting corrosion, loss of critical oil film clearance, and catastrophic failure of the main propulsion shaft.
INCURE WeldLock™ 356 Retaining Compound (Metallic Grey)
Stern tube assemblies, especially during maintenance or retrofit operations, often involve large component diameters and unavoidable clearance gaps due to wear, casting tolerances, or the need for a slight slip fit during assembly. The WeldLock™ 356 is the optimal choice for this job because it offers high structural strength coupled with a crucial ability to fill larger clearances (up to 0.25 mm diametral clearance). The metallic fillers ensure maximum contact and retention across slightly imperfect bores, creating a permanent, rigid bond that distributes the immense static and dynamic loads across the entire joint.
| Feature & Benefit | Technical Insight for Stern Tube Bearing Assemblies | Conversion Value |
| Gap Filling Capability | Formulated with metallic fillers to seal and bond clearances up to 0.25 mm, compensating for bore wear and large fit tolerances. | Permanent Seal: Achieves high retention strength even on worn or oversized stern tube bores. |
| High Shear Strength | Provides high structural strength, resisting axial forces(propeller thrust) and preventing bearing spin/walk under continuous radial load. | Lock Out Movement: Eliminates fretting corrosion and preserves the shaft’s critical alignment. |
| High Temperature Resistance | Withstands continuous operational temperatures up to 200∘C(392∘F), essential for joints that can generate friction heat. | End the Heat Threat: Guarantees the joint won’t fail or soften during continuous operation. |
| Marine/Oil Immunity | Inert to saltwater, marine lubricants, and oil-in-water emulsions, ensuring the integrity of the joint is protected within the stern tube environment. | Structural Durability: The bond remains permanently intact despite constant fluid saturation. |
Application Steps: Locking Stern Tube Bearings for Propulsion Safety
Preparation (Critical): Thoroughly clean both the bearing outer diameter (OD) and the stern tube bore. Remove all grease, oil, rust, and moisture. Use a powerful degreasing solvent (like acetone or industrial cleaner) and wipe until both metal surfaces are perfectly dry.
Application: Apply a generous and continuous bead of WeldLock™ 356 evenly around the bearing outer diameter or the inside circumference of the stern tube bore. Ensure the compound completely covers the entire mating area.
Assembly: Press or slide the bearing into the stern tube using the manufacturer’s specified tools. Ensure the component is fully seated. Wipe away any excess compound immediately.
Curing Time (Mandatory): Allow a full 24 hours for the compound to reach full cure strength before applying load or turning the propeller shaft. This is a crucial safety step for maximum structural integrity.
Stop risking main propulsion failure and ensure your stern tube bearings are absolutely locked for maximum vessel safety and reliability.