Press Stage 1

The skis I am designing this year use a cap rather than a sidewall.  Eliminating the vertical side wall creates a lighter ski with no reduction in strength or stiffness in addition to a ski that is less susceptible to top sheet damage.  In order to create a cap I have to press the ski in two stages.  The first stage attaches the base, edges, rubber foil, and fiberglass to the core.  Once these are connected, the flashing is trimmed and the sidewall is beveled to 30 degrees from vertical.

The first step is to attach mounting hardware to the core; this will ensure the core doesn't shift during pressing.  This is done by super gluing blocks on either side of the center line and drilling a hole through each block into the mold.  This allows a nail to be passed through into the mold.  The base is held in place by the fixture already attached to the mold.

 

A piece of plastic (2 mils thick) is cut to place between the ski and the mold.  This prevents excess epoxy from sticking to the mold.

 

The base is placed on the mold using a pre-attached alignment guide.  This guide is made from excess edge material and prevents the base from shifting forward or backward.

 

Once this is done, all material is staged.  This includes the fiberglass, rubber, core, base, reverse mold, and bladder.  The air compressor is also charged so that it will be ready to inflate the bladder.  At this time, I mix 1.25 cups of epoxy.  I use a west system two part epoxy (105 resin, 206 hardener) to make my skis.  Marine supply stores such as www.go2marine.com are great places to get epoxy.  http://www.go2marine.com/product/97792F/slow-epoxy-hardener-206.html

 



Once staged, the epoxy is applied to the base, rubber, fiberglass, and bottom of the core using a foam brush.

The press is then pressurized to 23 psi.  The pressure is checked periodically to ensure the pressure is maintained.  The epoxy has a pot life of 20-25 minutes and is hard within an hour.  The ski will remain in the press for roughly 12 hours to ensure the epoxy is fully cured.

 



 Once cured, the ski is removed from the press.

 

 

 

After the skis are removed, a jigsaw is used to trim the flashing from the edges.  The saw was set to a 30 degree angle and the cut was made from the bottom of the ski, using the edge as a guide.  This year the wood at the edge of the ski is aspen, which is a softer, lighter hardwood; this wood allowed the skis to be trimmed faster than in years past.

 

 

Once trimmed, the edges are sanded smooth with an 80 grit belt sander.

 

Typically, I would round the sidewall into the top of the ski to remove the sharp edge and allow the top sheet to easily bend over the ski.  This year I am adding "rails" to the top of the ski to add additional stiffness and will round the top of the rail.