The prototype hull of Alen Yachts' Metaphor 68.
The prototype hull of Alen Yachts' Metaphor 68.

The 20.5 m long yacht was designed by Italian company Victory Design. The hull for the prototype Metaphor 68 was produced by hand lay-up, but production hulls will be manufactured by vacuum infusion. Infusion has already been used for the production of the bulkheads and liners, which were then bonded into place with Crystic Crestomer 1152PA structural adhesive. The polyvinyl chloride (PVC) foam was bonded with Crestomer 1196PA using a recommended vacuum bagging technique which maximises the adhesive penetration into the gaps in a cross-cut scrim-backed foam for maximum performance. The deck was bonded to the hull using Crestomer 1181A.

Scott Bader says that this method of production using Crestomer structural adhesives where possible ensures low exotherms and low shrink with better mechanical properties of the composite. At the same time, there were the added benefits of making production faster and easier as well as reducing overall boat weight. Unnecessary lamination and mechanical bolt fixings were eliminated; even the engine beds were fixed with a Crestomer 1186PA adhesive.

Behind the gel-coat is Crystic Crestacoat 5000PA, a proprietary barriercoat, above the water line, and VE 679PA, a vinyl ester/DCPD skincoat, below the waterline, to eliminate print-through and protect from osmosis.

Turkish company METYX Composites' multiaxial fabrics were used in preference to woven rovings to further minimise print-through.

The overall system is reported to have resulted in an outstanding surface finish of the deck and hull. No evidence of the bulkhead is visible externally as vertical lines on the hull surface, says Scott Bader. This can be a problem area for some boat builders who use the more traditional laminate ‘tie-in’ method for attaching bulkheads as result of localised laminate shrinkage.

“This is the best gel-coated vessel surface that Alen has produced," states Emre Sandan, Assistant General Manager for Alen Yachts. “Using Scott Bader's latest products and technical expertise in both FRP tooling and boat building has also enabled Alen Yachts to produce one of the best gel-coated surface finishes now possible in the boat industry.”

The Metaphor 68 has an overall length of 20.5 m (68 ft), with 15.3 m at the waterline, 6.21 m beam and 1.1 m draft. The vessel has a displacement of 36.5 tons with a maximum speed of 45 knots from twin 1550hp Man diesels with Flexi Power Surface Drive. It also has a CE certification of category A from the Royal Institution of Naval Architects (RINA).

The launch of the first Metaphor 68 is planned for March 2008, with a planned production of six craft in the first year followed by a further 12 in the second year.

Further models are also planned. Production of a Metaphor 88 prototype will commence soon, with launch expected towards the end of 2008. A Metaphor 108 also being developed by Victory Design. A new Alen 425 Tender boat is scheduled to be launched in March 2008, and a new Alen 575 Lobster craft will be launched in August. The Alen 425 and Alen 325 craft will remain in production at the rate of 20 units per year.

“This is an excellent example of a real partnership approach between a boatyard, a distributor and a supplier,” reports Alen's Sandan. “We have been delighted with the service and co-operation provided by METYX Composites, who are Scott Bader's exclusive distributor in Turkey, as well as getting excellent technical and commercial support for this project provided locally from Scott Bader.”