CASE STUDY
Ballast Tank Refurbishment
OVERVIEW
A crude oil tanker required to return to charter before all of the scheduled ballast tank maintenance work could be completed during the vessel’s dry-docking. The remainder of the work would therefore be undertaken by a riding squad and the ship’s crew whilst the vessel was at sea.
CHALLENGE
Grit blasting could not be considered due to its extensive equipment requirements and H&S concerns. Therefore utilising water jetting and a compatible wet & rust tolerant coating system was the only possible solution. This is an innovative solution which is uniquely only offered by Chemco. There could also be no disruption or danger to the operating tanker.
SOLUTION
The WBTs were prepared by high pressure water jetting. Mechanical methods were also utilised to remove the majority of the heavy rust/scale. One stripe coat and one spray coat of solvent-free, wet & rust tolerant epoxy Epo-chem™ RS 500P were applied to the areas of existing steel suffering from corrosion damage. For areas where shop primed steel plates were inserted, one primer coat of Epo-chem™ RS 500P was applied, followed by one stripe coat and one topcoat of solvent-free, wet tolerant, glassflake epoxy Epo-chem™ RA 500M in accordance with IMO standards.
OUTCOME
The riding squad and ship’s crew successfully completed the remaining maintenance work within 14 days. Substantial time and cost savings were achieved by utilising this innovative solution offered by Chemco. The execution and completion of this project was only possible due to the unique combination of water jetting and the wet & rust tolerant characteristics of Chemco products Epo-chem™ RS 500P and Epo-chem™ RA 500M.
BENEFITS
• Solvent-free
• Wet & rust tolerant
• No requirements for grit blasting
• No requirements for dehumidification or ventilation
• No disruption to normal operating service of the vessel
• No requirements for dry-docking
• Reduced H&S and Fire Hazard
• No humidity or dew point restrictions
• Ballast possible after 4-8 hours – Coatings can ‘continue to cure’ underwater
• No over-coating limitations
• Compatible with almost all coatings, including shop primer