Why should rust prevention be part of ship husbandry? Corrosion control from a ship husbandry perspective

Why should rust prevention be part of ship husbandry? Corrosion control from a ship husbandry perspective

Make ship husbandry a major part of your operation and see how all aspects of basic care translate into massive cost savings on through-life costs.

Let’s look at some figures. The director of the World Corrosion Organisation estimates that the overall annual cost attributable to corrosion worldwide is around $1.8 trillion or around 2% of world GDP in 2007. In 2001 a US DoD estimate put it at, at least $20 billion per year as costs to that department alone. So we are talking considerable costs per annum here. However unless there is risk of catastrophic damage through corrosion as in pipelines or aircraft frames, very little attention is paid to most potential areas of corrosion.

Most of corrosion controls are reactive and ship husbandry is also a reactive process in a way, but what we are saying in this article is that very early treatment is nowhere near as expensive as later major treatment, so long as a little thought is applied both during ship design, build and for planned maintenance during service.

Let us look at how a routine can save time and money. Routine inspection and treatment of early signs of rust staining can stop a lot more damage than leaving it until the rust sets well in to the steel Rust staining is the first sign of problems beginning to set in, yet at this stage it takes very little time or effort to remove the staining and protect the steel. Consider. The basic chemical requirement for rust staining removal is quite safe to use, non-acidic and will not damage to any great degree the coatings. Greater areas of corrosion will require cutting out and/or re-welding, phosphating and similar surface treatments as well as more time required on replacing coatings. After the staining is removed, a small area will need one coat of paint, but the potential underlying problem has been identified and contained. Any corrosion usually starts with neglect.

Poor design can lead to corrosion – wells and sinks are water traps and eventually corrosion. Using an approach which is basic in the extreme will again save long term costs. Unless these can be designed out, keeping these areas dry by keeping them cleaned will go a long way to prevent corrosion settling in.. You will not need to spend a great deal of time on this routine task but you will need the will to do it. Design for smooth surfaces, excellent welding and good surface preparation, easily cleaned surface coatings will all contribute to better corrosion control. Rough and unsmoothed edges on superstructure welds form pits which positively invite corrosion. The design of a ship should include ease of fresh water wash down which is a simple but effective way of corrosion control.

Corrosion can affect most areas of a ship but when looked at from the point of view of basic routine cleaning it does not need to be such a big problem and is easily contained. No steel will corrode if the factors which cause that corrosion are completely minimized:

  • Paint and other coatings are kept intact
  • The right coating for the surface material is chosen or a supplementary low maintenance coating such as PTFE is chosen
  • Rust staining is treated immediately
  • Surfaces are cleaned and kept protected
  • Hidden areas with a high corrosion potential are also kept cleaned and any coating maintained This applies to wet vents and waste pipes, water lines and tanks, ballast tanks among others
  • Excessive and vigorous cleaning methods themselves will damage a coating, leading to corrosion setting in as will using the wrong cleaning products

Why not let Futureclean Assured Systems set up a ship cleaning system for you to reduce through life costs. Contact us today by email or phone.

 

Call us today or email us for a free initial discussion of your requirements and problems in this area

Mary de Cobos
mary@futurecleansystems.com