Profil „U“ 4,0 mm

An open section four millimeters wide

The cross section is formed by a web with two upright flanges, that is, the shape known in construction as a rolled U-channel. The width of 4.0 mm applies to the whole section and the strip measures 35 centimeters. The open side is itself an advantage: a thinner profile can be slid into it, bracing glued in, or a wire routed through the model hidden inside.

In the large scales the section corresponds to a serious piece of steel. At 1:24 it works out at roughly ten centimeters, at 1:35 at fourteen and at 1:48 at nineteen, which is the beam of a truck chassis frame or the running rail of heavy doors.

Where the shape does its work

• the side members of semitrailer and trailer frames,
• the guide rails of sliding gates and crane runways,
• the stringers of ladders and flights of stairs,
• the edging of platforms into which a floor plate is slid.

Recommended procedure

The strip is best divided in a jig, because an open section easily runs off into a skewed shape under a blade. Before you start gluing, check that the web is not twisted; a slight wave is straightened by a ruler pressed against it while the cement sets. The inside of the profile tends to be smoother after extrusion than the outside, so it holds paint less well and deserves a pass with a sponge before spraying. Cap the ends with a piece of smooth sheet, or a view into the cavity will remain and the illusion of solid steel will fall apart.

With weathering the open shape pays off: a wash flows into the inner corner by itself and creates a shadow there that gives the section depth without a single extra stroke of the brush.