Base and Edges

The base of the ski is critical to the way the ski will perform since the base holds the wax on which the skis glide. The base is made from Ultra High Molecular Weight Polyethylene (UHMWPE) which has been sintered and rolled into a sheet. Sintering is a method for making object from powder until the particles bond to each other (http://en.wikipedia.org/wiki/Sinter_). The nature of sintering allows for small pores to be created in the surface; in this case the pores allow the wax to be absorbed into the surface. One side of the base material comes abraded; this process scratches the surface and allows the epoxy to mechanically bond to the plastic.

The edges are made from hardened carbon steel and are designed so that epoxy can fill in the voids and create a strong bond. The edges have also been sand blasted to create a rougher surface for bonding. Since the edges are carbon steel, they will rust over time. Stainless steel of the same hardness would be prohibitively expensive.

The base material is relatively easy to work with since it can be cut with a razor blade. The base templates created earlier are used to quickly cut out the base shape. As mentioned earlier, the base template is critical as it will give the ski its final shape.

Once the base is cut out, the edges are tacked on on with superglue. The superglue is only applied every six inches in order to leave ample room for epoxy to bond. Clamps are used to hold the edge in place until it dries.

The edges can be bent around the tip of the ski, but without engineered bending equipment, this is a cumbersome task. Since the edges are hardened steel, they can be annealed (http://en.wikipedia.org/wiki/Annealing_(metallurgy)) with a torch to soften the metal. Once the metal is cool it is more ductile and can be more easily bent. Since the metal is softened, it will wear more quickly, but since it is at the tip or tail, hardness is not as critical.

The base and edge design of these skis does not require that any edges be bent. The base material is simply brought to the edge of the ski at the tip and tail. Although this design is more susceptible to damage, it has proven to be adequate in the past, especially with a cap ski design.

I had originally ordered 12 steel edges, but was only shipped 10 so one ski does not have the edges applied yet. I have contacted the supplier (www.skibuilders.com) to find out if they will ship me the two edges they overlooked.