The teflon-based ABCON Marine-Thruster Stop Leak (SL) additive stops or reduces leakages in thrusters by adding 2%-4% of volume to oil in the system.

We have products that are compatible with all kinds of thrusters lubricated with either mineral oil or bio degradable oil.

If you have a problem with a leak below 0.5l/h or 10l per day, then the Thruster SL is your choice. It can stop leakages from rotating and tunnel thruster units and it can stop leakages from controllable pitch propeller systems where there is a suspicion that the O-rings are worn or damaged.

Larger leaks

If you have a leak between 0.5l/h and 2l/h, then our Thruster SLL is the relevant choice. It has the same properties as Thruster SL but we have added some complex particles, which increases its effect.

Properties of Thruster Stop Leak

All our Thruster Stop Leak products have hydraulic oil as a base oil. This means that it is compatible with gear oil and hydraulic oil, and can therefore be used on fixed propellers and CPP propeller systems. It produces a barrier at the damaged area of the leaking seal ring. In addition, it protects the bearings and seals against wear and tear.

We also deliver to rotating thrusters, both Azimuth and Azipot.


The high content of complex particles produces a kind of a sealing layer on top of the seal. The effect is that the leakage is significantly reduced or stopped.

When SL or SLL is blended with the existing system’s oil, the blend produces an excellent lubrication, which due to the complex particles content, maintains its lubricating effect even if there is some saltwater in the oil.

Above mentioned products are available in biodegradable base oil. Those products are called Thruster BSL and Thruster BSLL. All ABCON biobased products comply with the 2013 EPA VGP requirements as environmentally acceptable.

Thruster Stop Leak products are easy to handle and can be added by own staff on board.

When assembling systems with rubber seals, a much higher protection can be established by using ABCON Marine Seal Protect+ on all seal surfaces.