IJSSELMUIDEN – Whoever said people in glass houses must not throw stones, never met Robert Nissink. His company, Royal-Maritiem, cuts, grinds, mills, drills, heats and bends glass surfaces for builders of yachts, large and small.

Given the superyacht sector’s extreme quality standards, says Nissink, means he has to master all manufacturing processes to turn glass into a hard-as-rock, good-looking and versatile building material.

Royal-Maritiem makes glass constructions for yachts of all sizes. Rapid developments in materials technology have led to unprecedented innovations in products and processes using adhesive bonding. Royal-Maritiem uses certified ‘European Adhesive Bonders.’

For very large yachts, the company offers yards an all-in package, from request to delivery, and names project managers to oversee calculations work, testing, production and assembly. The refit market, says Nissink, is special in that it can reveal surprises and require unique activities such as the dismantling of window parts.

“For yacht windows,” says Nissink, “we focus on structural bonding, so the glass package is applied directly to the structure. With glass, you have to work very precisely. In making calculations, you must consider the different expansion coefficients of the materials.”

Royal-Maritiem also makes glass windbreaks, stairways, steps, customized shower cabins, etc. It has a stock of about 100 tons of glass that is replenished weekly and is also used for other industries that work with Royal-Maritiem. “We source our glass from a regular manufacturer in Belgium and Luxembourg. It always comes from the same melting line to guarantee a stable end product,” says Nissink.

After measuring and engineering, glass sheets are cut to size. Then holes may be drilled for windshield wipers or milling cut-outs. In a dust-free space, white-suited workers make glass laminates. Next comes the shaping and heat-bending of glass on a mold. In the ‘hardening hall’ stands a 25m (82ft.) ‘oven’ with a 10 kV electrical connection, in which  glass is thermally pre-stressed, applying pressure and tensile stress to the material making it as strong as safety glass.

An alternative to thermal pre-stressing is chemical hardening. It boosts the surface tension up to 9 times the value of annealed glass rendering 9 times greater bending strength. Annealed glass is cooled slowly to room temperature, whereas tempered glass undergoes different heat treatment and is rapidly cooled.

Nissink says his company is doing research into an anti-reflective coating that minimizes reflection. “We are also developing a heat-resistant laminate that colors darker with the intensity of the sun, i.e., the stronger the sunlight, the stronger the hue.” Nissink had hoped to show some of its research at the 2020 METSTRADE show but it has been canceled due to the COVID-19 pandemic.