MarineLine® Benefits

In 2008 Marinspec Associates (MA), an independent testing laboratory, investigated the absorption and retention of chemical cargoes in organic cargo tank coatings prior to the carriage of vegetable oil cargoes.

In 2009, MA then compared the transmission characteristics of MarineLine 784 against a typical zinc silicate coating, a typical epoxy phenolic coating and stainless steel. The following surfaces were evaluated:

• Mild steel coated with an industry standard Ethyl Zinc Silicate coating
• Mild steel coated with an industry standard Epoxy Phenolic coating
• Mild steel coated with MarineLine 784 coating
• Stainless steel, grade 304

MA investigated the cargo absorption (and retention) characteristics of each of the surfaces under the same operational conditions with a view to comparing the contamination threat each surface posed, after exposure to Styrene Monomer (SM) and Ethylene Dicholoride (EDC), to subsequently loaded ambient temperature and high melting point vegetable oils.

RESULTS

1. The surfaces posing the least threat to the vegetable oils were MarineLine, Stainless Steel 304, and industry standard Zinc Silicate and with results reported from the laboratory being below the detection limit (2mg/kg) of the analytical equipment. However, it is important to note at this point that the stainless steel used in this project was new stainless steel, which was degreased and fully passivated prior to exposure to the chemical cargoes. Similarly, the zinc silicate used was a newly applied coating, which was washed in fresh water, dried, washed in clean toluene, and dried again, prior to exposure to the chemical cargoes. As such, these two surfaces can be considered to be in “new” condition. Had these two surfaces been in a “used” condition, their performance may have been different.

2. MarineLine 784 performed in much the same way reported in the first testing. The laboratory results for Styrene Monomer being consistently below the detection limit (2mg/kg) of the analytical equipment. The laboratory results showed very slight traces of EDC in the vegetable oil samples that were exposed to the panels that had been washed in the “cold” washing procedure (it should be noted that the panels that were “hot” washed, did not show any traces of EDC in the vegetable oil samples), but even so, after the results were adjusted to a surface area to volume contact ratio of 1 : 1, they were equivalent to a contamination threat of less than 0.30 mg/kg.

3. The surface posing by far the greatest threat was the industry standard epoxy phenolic coating. The results for transmission of both chemical cargoes show very similar trends to those reported in Marin 02/08 – FOSFA International reaching a maximum of 25.1 mg/kg for Styrene Monomer and 45.0 mg/kg for EDC.