Ulavales!

Document your personal work here. Show photos, movies, and share your secrets.

Moderators: Head Monkey, kelvin, bigKam, skidesmond, chrismp

Post Reply
kurtgross
Posts: 10
Joined: Tue Nov 08, 2005 7:07 pm
Location: Sequoia National Park, CA

Ulavales!

Post by kurtgross »

SKIS: Ulavale

Image

BUILDER: Kurt Gross

MANUFACTURED: 12/01/05 to 6/01/06

DIMENSIONS:
Ski Lenth: 176 cm
Tip Width: 118 mm
Waist Width: 84 mm
Tail Width: 111 mm
Camber: 15 mm
Weight: 3498 grams/pair

MATERIALS:
Core: maple and birch from White Pine Lumber
Base: Black UHMWPE from Crown Plastics
Topsheet: “Clear” UHMWPE from Crown Plastics
Edges: Steel from SkiBuilders.com
Epoxy: West Systems from McMaster-Carr
Fiberglass: 22 oz. tri-axially woven
Graphics: printed cotton fabric from Jo-Ann Fabrics

COMMENTS:
This was my first pair of homebuilt skis. Big Kam and his Klown Whackers inspired my design. I am a terrible skier, recovering from an ACL injury, and know very little about what makes a good ski or a bad ski. However, I know how to use all the tools required and I just like the idea of telling people "look at what I made". So, I took advantage of 24-hour access to a woodshop (and a cabinetry genius named Mike) at the museum where I worked and hunkered down.

To make up for my lack of skipertise, I hounded SkiBuilders.com throughout the design and manufacturing process. Since I am not a telemark skier, my design parameters were for a versatile randonnée set-up that would accommodate my skinny legs and developing skill level. Since I already own a pair of Atomic MX:7 skis (103/70/95), I wanted my homebuilt pair to be fatter. Without the time or money to goof through clever prototypes like the Kananas or Birds I hoped to start with a sure thing. SkiBuilders suggested the Klown Whackers as a template.

Image

A fully equipped woodshop at work made the whole process manageable and required a lot fewer overhead costs. Thanks to some precision band sawing (I held tolerances of +/- 0.5 mm!), I split two cores in half and ended up with wood for two pairs of skis. This put the whole production a generation ahead of schedule but I still haven’t used the second set of cores.

Image

The band saw picture shows how I split the 20 mm thick core in half. I used the deepest blade in the shop (only 3/8" front to back), raised the guard as high as it would go (5 1/2"), ran the work along a rip fence, kept the blade centered on a scribed line, and clamped thin washers in the gap behind the blade to keep the work from pinching and pulling the blade off the mark. Then I ran both book-matched halves through a planer to smooth the saw marks. I ended up with 8.75 mm thick cores! Not bad, considering the band saw is a Korean no-name model.

The cores are laminated 3/4" wide strips of maple and birch and profiled like the Ahmas (9mm thick at CC, 2mm thick at tips). After profiling the cores I feared the tips would not bend in the mold without breaking. They seemed really stiff when flexed by hand but ended up working out just fine.

Bending the metal edges was the bigger challenge. I used pliers, a bender, and brute hand strength but was not really satisfied in the end. In a few places, there were small gaps between the edges and bases that fortunately filled in with epoxy during the pressing. However, this was not a very elegant solution. This is an area that I can stand to improve upon for the next iteration.

I opted for wood sidewalls in order to keep things as simple as possible. After beveling the sides with a 15° dovetail bit, I sealed the wood with urethane then painted the sidewalls black. In spite of the beveling, a bit of the paint and sealant was shaved off when the ski shop sharpened the edges. I sealed and painted the sides again after that.

Image

I pressed the skis (with the help of my hero, John, who took a day off from building his house and his sailboat) in a vacuum bag with a constant pressure of 15 psi for 12 hours. Since the whole production dragged out over six months, I kept shelving the project and materials to keep from annoying my coworkers. In the process, I misplaced the vibration dampening strips and accidentally left them out of the final layup.

Image

The skis kept their camber out of the mold but are soft. Big Kam noted a similar finding in his review of the Klown Whackers. Perhaps I should have profiled the original cores instead of splitting them with the band saw. But like I said earlier, I don’t ski well enough to push anything to the limit so I’m not sure that a stiffer ski would mean much to me yet. My only real gripe so far is that the topsheet is not nearly as clear as I had hoped. The very vibrant orange fabric doesn't stand a chance through the moderately translucent UHMWPE.

Image

One other goof was the result of using the double stick tape on hand instead of running to the store to get something more appropriate. At the museum we use "thick" foam double stick tape to attach exhibit labels to gallery walls. Unfortunately, the tape is so thick that it formed dimples in the bases during the pressing. For the next batch I will get thinner double stick tape to secure the bases to the mold.

Image

My little sister is a third grade teacher in American Samoa and provided the name. "Ulavale" means naughty or misbehaved in Samoan and is what she often calls her students in class. I figured that was as good a name as any since these prototypes would probably end up misbehaving on the slopes anyway.

I mounted the skis with Dynafit Tourlite Tech randonnée bindings and skied with Garmont Dynamite G-Fit boots.

THE RIDE
I first rode the Ulavales on Tuesday, February 27, 2007 at Sierra Summit east of Fresno, CA. Back to back storms treated me to 18 inches of fresh powder and the best conditions of an otherwise bleak season. Putting down first tracks all morning, I took full advantage of the skis’ width. This was the first time I skied twin tips and sliding backwards down the gentler runs was a lot of fun.

Since that blissful day, I have only skied the Ulavales on variable backcountry conditions in Mineral King Valley (Sequoia National Park). Buried rocks have dug into both skis but so far the sticks have stood up to the abuse. When I tune them up next season, I’ll put a sharper finish on the edges to ensure that they will grab on the groomers. I think that will also be the test for whether they are stiff enough and if the VDS are really necessary.

Thanks Big Kam, Kelvin, Mike, John, and all the folks at SkiBuilders for the inspiration and support!
User avatar
bigKam
Site Admin
Posts: 538
Joined: Tue Feb 01, 2005 5:15 pm
Location: Park City, Utah
Contact:

Post by bigKam »

Kurt: like i said, a work of art! congrats on your first pair. i'm excited to ski with you when i come visit.
allyson
Posts: 43
Joined: Mon Jan 31, 2005 7:48 pm
Location: reno, nv

Post by allyson »

sweet lookin' ride, kurt! nice color choices too.
powdercow
Posts: 76
Joined: Mon Jul 31, 2006 1:35 pm
Location: Orem, Utah

Post by powdercow »

Excellent write up, clear concise and to the point. The skis look great as well. Double sides carpet tape is fairly thin and is very sticky so that might make a good option for you.

One question is how the topsheets "shed" snow when you are touring? As a fellow disciple of the dynafit cult, weight is important to me, and for touring skis I need to find something that won't have me hauling a bunch of snow up the hill.
- Ben
plywood
Posts: 499
Joined: Fri Oct 13, 2006 2:13 am
Location: wilen, switzerland
Contact:

Post by plywood »

great skis! like you i also had to learn my lesson with the stripes of tape covering the base.

an other point: if i got you right you think that the topsheet darkened your grafics and took them the brightness, right?
maybe it`s not just the topsheet. i recognized following as i did some tests for my 2nd pair: there i used light green cloth - actually it was light green, but as soon as i coated it with epoxy and everything got wet the colour turned dark. to get a higher contrast on the white parts of the cloth i had to put a sheet of thick white paper behind the cloth. by this i got a lighter background for the cloth than the brown wood.

so check this out. do some smaller testing sheets and hopefully you`ll find a way to get better results.

but darker skis look cool anyway ;)
plywood freeride industries - go ply, ride wood!
kurtgross
Posts: 10
Joined: Tue Nov 08, 2005 7:07 pm
Location: Sequoia National Park, CA

Post by kurtgross »

powdercow wrote:
One question is how the topsheets "shed" snow when you are touring? As a fellow disciple of the dynafit cult, weight is important to me, and for touring skis I need to find something that won't have me hauling a bunch of snow up the hill.
Ben,

Since the topsheets are Durasurf brand UHMWPE from Crown Plastics, they shed snow as well any commercially manufactured ski. I use globstopper wax on my skins to minimize snow clogging them and weighing me down. Earlier this season I used some vegetable oil cooking spray to lubricate my boots and eliminate a squeak. While I was at it, I sprayed a bit on the tops of the skis and hauled less snow uphill that outing than my colleagues. However, gouges on the topsheets from my own clumsiness and out-of-control snowboarders have since roughed things up enough to add plenty of friction. Truthfully, my best solution for making climbing less difficult is plenty of training and strong legs. Good luck.

Kurt
Post Reply