Static Fouling conditions in Korean Newbuilding Yards
Over the past 2-3 years, there has been a phenomenon of very high barnacle activity over the summer months in Korea and the fouling challenge has become extreme in Korean newbuilding yards under static conditions.
Barnacle fouling occurs during the breeding season when the larval density in inshore seawaters is highest. In Korea, the barnacle breeding season is generally from June to October and vessels are at greatest risk of barnacle fouling during this period. In recent years, the barnacle activity over summer months on the south coast of Korea has become particularly severe; this phenomenon appears to affect all paint technologies.
Deep sea antifouling products applied at newbuilding are designed to provide optimum protection for deep sea vessels in active service. The polishing and biocide leaching profiles of these coatings are designed to deliver protection for this end use. However, under the longer static conditions encountered during fitting-out at Newbuilding the product’s antifouling performance is generally lower than in deep sea environments where the vessel is active. This can cause problems where vessels are exposed to high fouling environments, particularly as seen in Korea over the last 2-3 years.
Until now, the solution has been to apply an additional fitting-out coat, but this raises other issues. For vessels which have very long fitting-out times (e.g. LNGs – typically >12 months), such a fitting-out coat is seen as an extra coat over the standard deep sea antifouling coating and causes a cost increase for ship owners and shipyards.
For most other vessel types that have shorter fitting-out periods, typically 2-3 months, using this specific fitting-out coating is not seen as practical. Of course, without this extra fitting-out coat there is an increased risk of fouling.
Interflex 8700 SPC has been developed as a solution to this problem and the specially developed formulation provides protection under static conditions in newbuilding yards.
Further testing has also shown that when Interflex 8700 SPC is used as a duplex with the standard deep sea antifouling, excellent performance during the fitting period is achieved. The scheme is also suitable for the full 60 months in service period once the vessel is in active service.
As this is used as a duplex system there are no extra coats of coating and therefore no extra cost to the yard or owner for fitting-out period and in-service.
Interflex 8700 SPC is based on a high solids copper acrylate Self-Polishing Copolymer with a specially selected biocide package that is effective in resisting fouling under both static conditions and in-service trading.
As this is a duplex scheme performance, once the vessels is in-service, it will be using Interflex 8700 SPC for approximately 1.5 – 2 years (depending on activity), then reverting to the standard deep sea antifouling for the remainder of the scheme life. Performance of Interflex 8700 SPC under in-service trading will be at least the same as Intersmooth or Intercept products, which are the premium products from International® range of marine coatings.