05/02/2019 11:00

In 2017, Chemco were approached by one of the world’s leading ship management companies to provide a solution for corrosion which had occurred within the water ballast tanks of a major crude oil tanker.

The ballast tanks had originally been coated in 2002, and were showing considerable wear and tear damage. As a result, they were looking for a new coating system to be applied.

Pictures: Original Conditions

The tanks were water-jetted to WJ-3 standard before one stripe coat and one full coat of solvent-free, wet & rust tolerant epoxy Epo-chem™ RS 500P were applied.

Pictures: After Surface Preparation and Completed Application Respectively

Due to the unexpected scale of the project, certain additional areas of the ballast tanks had to be coated in a conventional, solvent-based paint from a different coating manufacturer. This conventional paint was applied using the same surface preparation, shipyard crew and at the same time as Chemco’s RS 500P.

After 1 year in-service, the ship management company carried out tank inspections and found a clear difference in quality between the tanks coated by Chemco, and those coated by the separate manufacturer. The conventional paint system was failing after only 1 year, whereas Chemco’s RS 500P remained in very good condition.

Pictures After 1 Year In-service: Chemco (Left) v Conventional Coatings (Right)

The below chart compares the two coating systems utilised in this project; Chemco’s Epo-chem™ RS 500P and the conventional, solvent-based paint:

Coating Comparison Chart


Epo-chem™ RS 500P

Conventional Paint

Surface Preparation

Water Jetting (WJ-3)

Water Jetting (WJ-3)

Application Timeframe

Can be applied immediately after surface preparation (no need to dry substrate)

Surface must be completely dry

Volumes Solid

100% (Solvent-free)


Environmental Conditions

No humidity or dew point restrictions

If humidity above 85%, do not apply

Dehumidification or Ventilation

No extensive requirements

Large and expensive dehumidification and ventilation equipment requirements

Overcoating Intervals

No limitations

3 months

Health & Safety / Fire Hazard

Environmentally and applicator friendly process

Solvent-based, considerably increases environmental and applicator risks

Operational Shutdown

No shutdown required. Nearby work (including hot work) can continue without disruption

All surrounding trades (especially hot work) cannot continue

Back-in-Service Times

Ballast after 4-8 hours (can ‘continue to cure’ underwater)

Must be allowed to full cure (up to 14 days)

The unique characteristics of Chemco’s coating system ensure a durable, long-lasting performance which is perfectly suited to withstand the internal rigours of water ballast tanks.

The premature rust exhibited by the non-Chemco coating will invariably lead to a deterioration of the ballast tanks; having a negative impact on their long-term safety and performance.


Learn more about Chemco’s innovative RS 500P and ballast tank coatings by clicking the links below:


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