ABCON Marine-Stern Tube Stop Leak (SL) is a teflon-based product designed to stop water ingress.

It counters the negative effects of water can have on the system, including less lubrication and more corrosion.

STERN TUBE is a stop leak paste that also stops water ingress, which is the reverse side of oil leak. When ABCON Stop Leak is added to the system the content of teflon and other complex particles forms a barrier on the surface of the damaged seal ring. This stops water ingress and leakage.

We have a broad assortment of products that work with all types of stern tubes. They all stop leaks and water ingress on stern tube seals and other similar systems where mineral based engine oil or biodegradable oil is used.

Lip seals

In the case of a smaller leak below 15l-20l per day, then the Stern Tube SL is the best product to use.

If you have a larger leak than 15l-100l, 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 produces 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 a biodegradable 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.