As seen in: Hamburger Abendblatt / October 2007
Polyurethanes and exoxy resins provide a pleasant appearance as well as corrosion protection “The surface of a yacht is supposed to look as smooth and shiny as if it had just been coated and not quite dried yet – this is what experts call the ‘wet-look’. It has to be UV- and abrasion-resistant as well as easy to clean.” Thus Mr Peter Witte, member of the Mankiewicz executive board, characterizes the essential requirements on paints for luxury yachts. Mankiewicz, an old-established company of Wilhelmsburg with 700 employees, suppliers its paints mainly to shipyards, for the building of large yachts of 30 metres upward.
Mankiewicz is one of the few, perhaps one dozen, paint manufacturers leading the field worldwide in the development of new products. So far, this included paints and primers for the aviation and automotive industries; recently, yacht paints with the trade name ALEXSEAL were added. As base materials the paint experts prefer epoxy resins and polyurethanes, Resins, sealing the surface, offer excellent corrosion protection; polyurethanes are used in the topcoats for visual, weather- and UV stability reasons.
“We are in the process of bringing so-called sol-gel technologies to the market, thereby combining the classic paint chemistry with glass and ceramic chemistries”, Mr Witte says. New formulations ensure glass-like surfaces that are easy to clean and extremely scratch resistant. Organic elements keep the coating – in contrast to glass – from becoming brittle and fragile.
While competitors increasingly promote the use of nanotechnology, the Wilhelmsburg company is reserved. Although also using these new structures which are smaller than a micrometre (one millionth of a metre), it is not calling them “nano”; the term was already used to excess, Mr Witte explains. The lotus effect, i.e. reconstructing the self-cleaning surface of lotus leaves, is the most famous application of nanotechnology. This surface is not smooth, but – if magnified – looks like a tight agglomeration of nails which drops of water and particles of dirt cannot penetrate, thus remaining on the tips and rolling off very easily.
“This system does not work for boat paints”, Mr Witte says, “if the ship hits a bollard or something else scratches the surface, the structure is damaged”. Lotus-effect surfaces are far too sensitive for objects of daily use. However, finest nano substances are included in the paints: to adjust consistency and viscosity or as pigments.
Regarding pigments, the paint pioneers experiment with yet another novelty: pigments reflecting infrared radiation with the effect that dark-painted boats get less heated up by the sun, thus relieving the mostly present air-conditioning systems. These new colours are still awaiting practical testing, for
example in a test area in the western US where mirrors collect the Californian sun, concentrate it and
channel it to the paints which must not change in the process.
Picture: In a climate chamber, Mr Heiko Bandholz checks how yacht paints react to a humid environment. There, test objects are stored for 2,000 to 3,0000 hours (left photograph). Mr Peter Witte, member of the Mankiewicz executive board, is also responsible for the research laboratory.