Stern Tube – Leakage

Leakages in stern tubes occur when they are least expected. But by adding 5-10% (by volume) to existing systems oil ABCON MARINE-STERN TUBE SL (Stop Leak) teflon based product it forms a teflon barrier to prevent further leakage.

There are several causes of leak such as fishing lines pulled into seals, sand and other impurities damaging seals when passing through shallow waters, insufficient lubrication of seals during dry dock, air locks in CPP’s after assembling, oil film pressed out during stand still. We have products that cover both smaller and larger leaks in the different kind of seals.

Lip Seals

In the case of a smaller leak below 15-20 liters per day, then the STERN TUBE SL is the best product to use.

If you have a larger leak than 15-100 liters, then our STERN TUBE SLL is the relevant choice. It has the same properties as STERN TUBE SL, but contains larger and more complex particles.

Face Seals

For face seals, we have our ABCON MARINE-STERN TUBE CSL which is designed to stop leaks in small and large Cedervall type systems.

Properties of STERN TUBE SL

The unique properties of our stop leak products are their abilities to produce a teflon barrier on the leaking area as well as reducing wear and tear. It also protects again corrosion.


The high content of teflon and other complex particles produce a barrier on the damaged surface of the seal ring. The result is that the leakage is significantly reduced or stopped. Should there be water in the lube oil, the stern tube paste will provide a substantial safety margin as teflon maintains its lubrication properties even in water.

STERN TUBE SL, SLL and CSL can be blended with all types of mineral lubrication oil. It can be used with all types of stern tube seal materials.

Above mentioned products are also available with Bio degradable oil based version. They all comply with 2013 EPA VGP requirements as environmentally acceptable. They are all named with a B (BSL, BSLL, BCSL)

Our products are easy to use and can be added by own staff on board the vessel.

When assembling systems with rubber seals a much higher protection can be established by using ABCON MARINE SEAL PROTECT+ on all seal surfaces.

For information about studies and detailed product info please contact ABCON by e-mail: