MarineLine® E-Newsletters

Profitable Tanker News about Marine Cargo Tank Coatings
Issue 07
Cargo Tank Stories From The High Seas
In this issue, APC would like to share other stories and comments it has received on the MarineLine® cargo tank coating, over the course of many years of service in which it has been subjected to a wide range of different chemicals, operating environments, and applications. Here are several stories you may find useful.
First, to follow up last month’s conclusion of the 3-part series on ‘Taking Care of Your Coatings,’ Advanced Polymer Coatings received some excellent commentary on this topic. One maritime tanker fleet executive circulated a memo to his staff to: “Please have these instructions printed and laminated and provided to all our MarineLine® coated vessels. The instructions should be prominently displayed in multiple locations and the crew should be trained and reminded to follow these procedures. A copy of these instructions should also be in our onboard manuals on coating maintenance.”

If you would also like to use these three special issues, we have produced them in a printable PDF form for your download at the following links.
High Seas
1MarineLine® Coatings - Application
2MarineLine® Coatings - Cleaning
3MarineLine® Coatings - Maintenance

This cargo tank (shown below), coated in a Turkish yard with MarineLine® 784, has successfully carried many loads of methanol over its 5 years of service. This photo was taken during a recent on-board inspection of the coating. Only minor touch-up tank repairs were needed and the ship was quickly put back in service.

A shipowner with MarineLine®-coated tanks still in good condition after seven (7) years service fell into a difficult economic situation due to lower chartering rates. One way to make up the difference was to perform little to no coatings maintenance, yet still continue to operate and use the tanks in a similar manner. Thus it was no surprise that after its most recent major inspection, the MarineLine® coating was shown to exhibit excessive wear and tear, which then led to a full tank re-coating being required. Short term, the ship owner saved on some costs; long term the ship required a full tank re-coating that was more costly due to lack of maintenance.

In this instance, a problem occurred NOT with the carriage of a chemical, but with the use of a non-approved chemical in the cargo tank for other purposes. A MarineLine®-coated ship was purchased from another owner. The new owner wanted to passify the stainless steel steam coils and piping in the tank. In order to passify, they put a 70% concentration of Nitric Acid in the tank. This however caused discoloration of the MarineLine® coating because a 70% concentration or more of Nitric Acid in the tank is clearly NOT approved in the APC/MarineLine® Chemical Resistance Guide. So if there are any questions, contact APC, especially in unusual situations.


In this time of economic uncertainty, both shipyards and shipowners are trying to get the most out of their assets in order to make a profit. Coating a tanker’s cargo tanks has one of the lowest priorities at the shipyard, yet it is one of the most important factors in making a profit for the shipowner. Many shipyards that are in a difficult financial condition have been cutting corners in order to meet contract delivery dates. For example, during construction, ships are moved about to various areas in the shipyard causing different environmental conditions than those originally specified by APC, and this affects the application work. A shipyard may also turn off dehumidification equipment for long stretches during the evenings after the first (1st) coat has just been applied, in order to save on energy costs. A shipyard may not be properly exhausting solvent vapor from the bottom of the tank during and after spraying which can cause solvent to become entrapped in the coating. Some of these issues were proven to have actually happened after an inspection onboard several tankers where coatings problems arose. Two different tankers had been sprayed; one with MarineLine® and the other with a competitor’s coating, and both had problems related to the previously stated ‘shortcuts’. This was proven as both tankers were done at the same shipyard. In time, the ships were removed from active service and taken to another shipyard where the tanks were blasted clean and carefully re-coated to the correct APC application performance standards. Today the MarineLine® ships are operating well and are in full service carrying a wide range of veg oils and methanol. This illustrates the importance of avoiding shortcuts during initial application stages and keeping a close eye on the coating installation.

If you have questions on the maintenance of your MarineLine® 784 cargo tank coating, contact your Advanced Polymer Coatings’ representative to learn more why MarineLine® 784 is unique in the maritime industry.