V-Groove Siding (1,0 x 0,75 x 0,25)

A sharp groove bottom makes the shadow

A system of grooves with a V-shaped bottom is milled into the surface of millimeter-thick polystyrene. Neighboring grooves are three quarters of a millimeter apart and the groove is a quarter of a millimeter deep. The sharp bottom is exactly why this pattern is used rather than a mere scribed line: a shadow holds in it under the paint and the joint between boards stays legible even after several coats.

Joining without a visible seam

Styrene is not joined by a layer of material between the parts but by a weld. Liquid cement for plastics is applied with a small brush to the place where two parts touch and it soaks into the joint by itself. The surface of both parts softens, once they are pressed together the material mixes, and after curing the joint holds more firmly than the material around it. The procedure has two rules. First, the parts have to sit against each other before the cement goes on, because it will not fill a gap. Second, the part must not be moved after it has been placed until the softened layer has set, or the pattern will smear where the joint is. Any excess that wicks out is better left to dry and only then trimmed off.

Where the pattern looks convincing

A spacing of three quarters of a millimeter corresponds, at a reduction of one to seventy-two, to a board about five and a half centimeters wide, and in 1:87 it comes out at six and a half. These are therefore narrow boarded surfaces: the walls of shelters and sheds, doors with battens butted together, the soffits of gables, the cladding of platform shelters. In large scales the grooves read as fine ribbing, which serves well for instance on a corrugated door panel or the ribbing of a cabinet.