Press Stage 2

In past years I have created the graphic on cotton cloth or on paper, but this year my sister (Emily) and I decided to create the graphic directly on the wood core.  In order to do this, we wanted to first stain the wood to get a deeper background color.  I wasn't sure if this epoxy would still stick to the stain, so I performed a test.

The test showed that although the epoxy didn't stick as well on the stain as on bare wood, it would be sufficient to keep the top sheet on during use.  Based on the successful test, I stained both skis.

Next, my sister, with a small amount of help from me, painted the ski graphic.  The graphic is based on Revelation 19:11-13:

¹¹ I saw heaven standing open and there before me was a white horse, whose rider is called Faithful and True. With justice he judges and wages war. ¹² His eyes are like blazing fire, and on his head are many crowns. He has a name written on him that no one knows but he himself. ¹³ He is dressed in a robe dipped in blood, and his name is the Word of God.
  
The graphic was intentionally made with great detail on the tail of the ski and with much less detail at the tip.

Next the skis were put in the press. A full sheet of fiberglass was not place on the top of the ski, only a narrow strip was placed on each edge of the ski.

The flashing was trimmed off with a jig saw and the edges were finished with a bench top belt sander and hand belt sander.

The final step was to peel off the tape that was protecting the top sheet and base.  This was done relatively easily, but it would have helped if the tape was a little thicker to prevent it from tearing.

 

 

Prior to pressing the skis, I placed a nameplate at boot center on each ski.

 

 The only thing left to do is mount the bindings and tune the skis.

Press Stage 1

This year the base material is transparent so I added a simple graphic to the bottom of the ski with acrylic paint. To prevent the paint from bleeding underneath the stencil, I applied spray glue to the stencil first.  I bought this glue not realizing it was only "general performance"; this just means it's not actually sticky - which was perfect for this application, but not for actually gluing things.

The next step was to layup the ski and press it.  Since it had been a year since I last used the press, I tightened the bolts, perform a pressure test, and verified that there were no cracks in the wood members.  This year I went back to a MAS FLAG epoxy (medium viscosity resin and hardener).  I used this epoxy for my prototype and year 2 skis and it has performed well over the years.  I have used the prototype skis (Goliath) on a nearby fly ash dump several times.  This is kind of an accelerated damage test for the skis.

The image below shows the skis after removal from the press before the flashing was cut off.

I used my jig saw to cut the flashing off; however, someday I plan to have a more powerful band saw to do the work.  I purchased a new belt sander over the winter with a 6" x 48" belt; this made quick work of cleaning up the edges.  I still used my hand belt sander to smooth the edge bevel.

The skis are now ready for graphics and top sheet which will be applied during the final press stage.

 

Layer Prep

To get the ski ready to press, the edges, base, fiberglass, rubber, and top sheet must be prepared.  This year I purchased clear base material which will allow me to put some graphics on the bottom of the ski.  A razor blade and the base template are used to cut the base material to size.

 The edges are clamped in place and temporarily attached using super glue.

The image below illustrates the opacity of the base material.  When epoxy is applied, the material will become more clear.  The edges, black rubber, graphics, and core design will show clearly.

In order to protect the base from epoxy and damage, tape is applied.  This year I purchased 6" wide label tape from McMaster-Carr.  In past years I have used both contact paper and packing tape which both have their difficulties. Packing tape is applied in strips, and any overlap will leave minor depressions in the base material.  Contact paper uniformly covered the base, but was hard to apply and remove. This tape was by far the easiest to apply out of anything I used.  I built a tape dispenser to help me apply the tape to the base.

Once the tape was stretched out, a paint roller was used to evenly apply the tape to the base.  Because there was tension in the tape during application, there were no creases or bubbles.

The extra tape was then trimmed using a razor blade.

The top sheet, made from p-tex, is also clear and was cut in half and covered in tape similar to the base material.

Rubber is placed between the steel edge and fiberglass layer in order to prevent delamination due to shear between layers. The rubber comes in a roll and was simply cut into four pieces.

There is a fiberglass later between the base and core and between the core and top sheet.  The fiberglass on the base is 19 oz with a tri-axial weave (45, 90, and 135 degrees).

I did not purchase new fiberglass for the top of the core, but used some old bi-axial fiberglass (0 and 90 degrees).  Rather than covering the entire top of the ski, which adds considerable weight, only the edges will be covered.  This strip of fiberglass was cut into four pieces.

The ski is nearly ready to enter press stage one; however, graphics will be applied to the core prior to pressing.

The Core

It has been about 4 months since I have done any work on my skis because our second daughter was born in April. She is a wonderful blessing to our family and worth suspending ski building operations for.  I am excited for the day when my children out-ski me for the first time.

"Exactly one day in your life your kid will ski as good as you do. The next day, he'll ski better than you."
-Warren Miller

The Aftermath 2 core is nearly identical to the Aftermath gen 1 core except that cedar was substituted for several aspen members to lighten the core.  Also, the oak rails will not be included with this model since they provide too much stiffness.  This will be my lightest core ever.  The core is comprised of 13 members as shown below:

This is my first year using cedar and I had to find a piece with no knots, but this turned out to be pretty easy; all the wood was purchased at Lowe's.  Cutting the core members is fairly straightforward with a table saw - just watch your fingers with the 5mm wide pieces.

 

 

Once done, I used my core member template to cut the two curved aspen members for each ski.  Then I used a 50 grit belt on my belt sander to finish the cuts.  Clamping the boards together allows the sander to ride perpendicular to the top of the member.  It also ensures all the members are identical.

 

Aspen Curved

 Aspen Straight 

 

 Oak

 

 Cedar

 

 Poplar

 

 

 

 

Once the sanding was complete, all the wood was wiped clean with a damp cloth.  Wood glue, clamps, and a paint roller were used to join the core members.

 

The core is in its final stages now and can be planed down from 19mm to 12mm thick.

Next the core template is used to round the tip and tail of the core blank.

 

The ski is then clamped into the profiling jig and a router is used to machine the core blank to thickness.  The tip and tail are machined from 12mm to 2mm.

Another sanding, this time with 80 grit sandpaper, is needed to smooth out the surface created by the router.  The core is now ready for layup.