Image of the inside of the cylinder liner on the MV Eget with wave cuts clearly visible


Lacquering / black spot on cylinder liner

January 2020

Relevant to Technical Managers operating vessels in areas of high humidity.

This service information covers the technical explanation for formation of lacquering on the cylinder liner, and how to deal with this condition.

Please contact our After Sales department for further information and scheduling a visit by our engineer.

T: +45 9857 1911


How to deal with lacquering

Experience has shown that normal cylinder condition is maintained despite the presence of black spots. Lacquering is a fully harmless symptom which in general has no negative effect on the operational condition of the engine, and there is therefore no problem in continuing engine operation despite the presence of black spots.

We recommend disregarding the presence of black spots when evaluating the cylinder condition, and determine the cylinder oil feed rate based on other parameters such as piston and piston ring condition as well as analysis of scrape down oil.

Please read the flyer PDF for a more detailed explanation.

Make a quick estimate of your cylinder lube oil savings and liner condition, using Hans Jensen Lubricators on your 2-stroke engines.
Calculate your savings potential