varying conditions through life, and this

standard may be too high for some ship

classess

• the recommended salt limits before

secondary surface preparation is set at

</=30mg/m

2

.

This will create problems for yards using

fresh water washing, as some fresh water

supplies may be unable to achieve this

• the grading of coatings as 'Good, Fair, or

Poor' lacks an industry-wide consistency

and also varies between classification

societies

• many of the newer high-volume solids

products do not yet have a 15-year track

record.

This standard will pose challenges for yards

and paint suppliers alike. Many yards are also

concerned about the changes, which this will

mean alterations to their well-established

working practices plus associated implications

on build costs and production time. This could

have the effect of significantly increasing the

work content.

The product types featured in the articles

presented in this feature focus on the following

areas:

• top-coats - for external superstructure and

house colours

• antifouling and foul-release coatings - for

drag reduction and fuel savings

• universal primers - to reduce the number of

products used to coat a ship.

Topcoats are critical for the appearance of a

vessel or offshore structure and often create a

very important first impression for third parties.

The ranges of most leading marine coatings

companies include products based on a variety

of chemistries including: alkyds, polyurethanes,

epoxies, vinyls, acrylics, and, more recently,

polysiloxanes. In this area, Jotun has introduced

its Hardtop Flexi, while Ameron has had its

PSX technology (introduced in the mid-1990s)

recognised in the USA.

Antifouling solutions have gone through

tremendous changes in the last few years with

the demise of TBT SPC products which have

been the mainstay of the industry for several

decades. The solution envelope has broadly

focussed down to two technologies (although

there are some novel and alternative

technologies out there at various stages of

testing).

These two technologies are copper-based

SPC antifouling products that broadly reflect

the banned TBT SPC products and match them

in technology and performance, and foul-

release technology (low-surface-energy

coatings).

The demise of TBT-based products left gaps

in the product ranges of all paint companies, and

the recent product launches by Hempel

(Olympic) and Jotun (SeaForce) are aimed at

ensuring all vessel type requirements can be

catered for, based on speed, level of activity, and

trade patterns. For many years, foul-release

technology has been led by International Paint,

but as that leading company celebrates its 100th

application, the choice in the market place is

increasing, with offerings from Hempel

(Hempasil) and Sigma (Sigmaglide).

These products do not polish or contain booster

biocides, instead they offer a very smooth, low-

surface-energy surface, to which it is difficult for

fouling to adhere. Consequently, when the vessel

is stationary, some fouling may occur, but as the

ship builds up to its required critical speed, the

fouling is released. These products offer a

potential of a long service life well in excess of

five years, but can suffer from mechanical

damage.

They are proving very popular on large

container vessels and are being specified on some

of the new LNG carrier orders. The use of silicone

does present some challenges for shipyards to

control the potential for contamination of other

surfaces by silicone, and to date, the majority of

applications have been in repair drydocks.

Finally, universal primers are playing an

increasingly important role in simplifying the

coating process, both at newbuilding stage and

during maintenance and repair, by reducing the

total number of products required to coat any

given ship. These products are designed to be

applicable to most vessel areas as a first-coat anti-

corrosive and to be over-coated by a variety of

products.

They afford through life protection for a variety

of environments. A welcome addition to the

products on offer from many of the leading paint

companies is Hempadur Uniq (from Hempel), as

a solution to this problem that is faced by both

owners and yards alike.

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