Overview Primarily, the
sidewalls of ski serve to protect the wood core from moisture damage and impact.
The most common materials used for sidewall construction are ABS plastic and
UHMWPE (P-Tex). These plastics are ideal in that they are both extremely
durable as well as have a high resistance to moisture absorption. However,
sidewalls can also be made from wood or even epoxy. Each method is
Making Wood Sidewalls Wood sidewalls are the easiest to
make. To make wood sidewalls, simply make the ski's core wider
than the ski's base (w/ edges) and layup the ski as usual. After the ski comes out of
the press, trim the excess material exposing the wood sidewalls. Be sure
to treat the wood with some sort of wood treatment to prevent moisture damage.
If you plan to use different types of wood for your core, one option to
consider is laminating the harder woods near the edge of the ski. Harder
woods are usually more durable.
Making Epoxy Sidewalls Epoxy sidewalls are the easiest to make,
and they can can be made into different colors, whereas ABS/P-Tex plastic usually
only come in
black or white. Colored
epoxy is achieved by using special pigments designed specifically for epoxy.
There are several methods for making epoxy sidewalls. One method (we
call the Moat method) is to form the epoxy around
the blank wood core, then profile the core with the attached epoxy.
Another method (referred to as the Trough method) forms the epoxy sidewalls
after the wood core has been profiled. Both of these techniques are
outlined below beginning with the Moat method.
Step 1: Router Out A Channel in the Core To make epoxy
sidewalls, begin by using a router with a template to cut out a moat, or
surrounds the ski's perimeter within the blank core. The template should be made so that the
center of the router bit (1/2"-1" diameter) will align with the ski's metal
edge. The diameter of your router bit will determine the size of the
channel and in effect the width of the sidewall. So choose the
router bit accordingly. Typically you would use the a double-edged
straight router bit (1/2"-1" in diameter) along with an appropriate sized
bearing to follow the template. An example of such a setup is shown below:
The key is to ensure that there will be enough sidewall material to protect
the core and also to cover the metal edges. When routering, make sure the
bit doesn't cut through the entire depth of the core. The main
objective is to create a moat that will hold the epoxy as it cures. For
example, the picture below illustrates the process:
Step 2: Fill Channel with Epoxy After the channel
has been routed, simply feel the trough with epoxy, then wait until it cures
before profiling the core.
Notice that this method creates both the sidewalls and tip spacers.
Step 1: Attach Plexi-Glass to Profiled Core Cut two
rectangular pieces of plexi-glass that are as long as your core and
approximately 3-4 inches wide. With your profiled core clamped vertically
so that one edge is facing upwards, secure the plexi-glass to the profiled core
using strong double-sided duct tape along with clamps. A trough should be
created as shown below:
Try to make sure the core is as level as possible. If not,
epoxy will build up entirely on one side.
Step 2: Pour Epoxy Mix up your epoxy (the
same kind used during layup) and add any color pigments at this stage.
Carefully pour the epoxy into the trough. Check for any leaks.
Keep adding epoxy until you have the desired width of sidewall.
Step 3: Finishing After the epoxy has
completely cured, carefully remove the plexi-glass. Sand the surface of
the epoxy with some rough grit sandpaper so that it bonds well during layup.
Keep in mind that the above steps have to be repeated three more times for the
Making ABS or P-Tex Sidewalls Making ABS/P-Tex sidewalls requires the
most work out of the three methods, however, the results are much stronger than
those obtained by using wood or epoxy. The outline below demonstrates how
ABS/P-Tex sidewalls are attached to a wood core. Note that the method is
the same whether you choose to use ABS or P-Tex.
Step 1: Trim Wood Core to Shape Before you can attach the
sidewalls you must cut the blank (not profiled) wood core to shape using a band
saw or jig saw.
When cutting your core to shape keep in mind that you must leave enough room
for the plastic sidewall material. The actual width of the sidewall
is up to you to determine but typical widths range from 1/4" to 3/4". The
following picture shows the wood core on top of the base material (w/ edges
Notice that there is about 1/4" of room for the sidewalls to extend into the
ski. When attached, the sidewalls will actually cover the edges and
overhang them (the excess material is trimmed off in the finishing process).
Also note that the tip of the core is only roughly cut. This is because
this portion will undergo additional trimming when attaching the tipspacers so a
precise cut is not necessary at this point.
Step 2: Rip Plastic Into Strips After the core has been
cut, the plastic needs to be prepared. You usually find thick ABS/P-Tex
material in large sheet forms (1/2" x 48" x 96"). These sheets need be
ripped into strips using a table saw or any other saw you are comfortable with.
For a pair of skis, you will need four strips (two for each side of a ski).
The width of the sidewalls strips vary depending on your ski design. Just
make sure that you have enough to overhang the ski's edge by approximately 1/4"
Step 3: Flame Treat the Strips Most manufacturers of ABS
or P-Tex recommend that you flame treat the plastic before it is bonded to the
core. This is done by simply using a torch and quickly passing the
flame over the plastic.
Only let the torch stay in one location long enough just to slightly darken
the plastic material as shown below.
You only need to flame treat the side that you intend to bond to the wood
core. The other sides (top-side and base-side) will be flame treated after
the core has been profiled.
Step 4: Attach Sidewalls to Core Mix up a small amount of
epoxy (the same kind that you will use for layup or something similar).
Use a small, disposable brush to apply the epoxy to the vertical sides of the
wood core. Then apply another generous amount of epoxy to the flame
treated sides of the sidewalls. Arrange the sidewalls and core
together and secure into place with some clamps as shown.
After the epoxy has completely dried, remove clamps and proceed to the next
step of profiling of the core.
Note that it is also possible to make a full wrap around the core with the
ABS/P-Tex to create both the sidewalls and tipspacers at once. However,
this requires a little more work and the plastic will have a greater tendency to
"blow out" during skiing.