Ok, so this ski I’m building now will be used at the Blandford Ski Area SnowSports school where I work part time, www.skiblandford.org. I hope to have it done by the time we report for our orientation on 12/2. Next I’ll start documenting the steps to get this ski built.
Here’s the basic set of materials that will go into this ski:
The stack of wood will be the wood core. It consists of ash which will be under the binding area. Douglas Fir for the tip and tail sections, and maple for the sidewalls. I’ll glue this up and profile the core tomorrow (sat 11/19/11) .
This ski will be 168cm in length. The core will be 3-10-3, meaning 3mm thick at the tip, 10mm thick in the middle and 3mm thick in the tail. I made the core a few inches longer on each end to account for planer snipe.
Some basic terminology:
Running Length (RL) – the length of the ski between the contact points of the tip and tail. Generally it’s the length of the ski, minus the length of the tip and the tail.
Boot Center – Generally it’s the 1/2 the RL. This can vary depending on personal preference or the type of ski. So if the RL is 1480mm, the BC is at 740mm.
There are specific reference marks that I retain through out the process. They are:
- Where tip starts and stops
- Where the binding area will be
- Where the tail starts and stops.
- The most important is the Boot Center (BC). This is the location where the center of the ski lines up on the ski. Every ski boot has a mark indicating the center of the boot.
This is the wood core that I glued up the night before and it’s ready to be profiled using my planer and a planer crib.
Here’s the planer crib. The middle of the crib is lower than the ends. When the crib and wood core passes through the planer the rollers push down on the wood core, therefore taking more wood off the ends than in the middle. The black strips are grip tape to keep the wood core from sliding/moving while being planed.
The brown panels are adjustable. They are wedge shape and go from 12mm thick on the very end to 2mm toward the center of the crib. I adjust the correct position depending on the length of the wood core.
After about 15-20 passes through the planer the core is done.
The wood cores are placed on the planer crib and it’s ready for planing.
Here is the final wood core. I always label the core so I know which is the top and which is the bottom. During the layup process I’ll add in 2 thin layers of ash veneer on each core for the tip area. This will bring the ski to it’s final length of 168cm.
Now that the core is done the next step will be to shape the P-Tex base and apply the metal edges. That’s done by using a CNC template that I designed and had cut but EastMountain Woodworking in Holyoke http://www.eastmountainwoodworking.com/ . The template is basically the ski flattened out.
That’s it for now. Check back in a couple days.
So it’s been more than a couple days but made some minor progress. Today I hand bent the edges, cut the base material out, cut the fiberglass. Here’s some tools I used today to accomplish some tasks.
The pliers on the left I use to fine tune the bending of the edges. The box cutter is used to rough cut the p-tex base. The rotary cutter is super sharp and is used for cutting material and fiberglass. The blue handle pliers or dykes are used for cutting the metal edges to length.
All the little black specs are from the p-tex base when I routed out the base.
The metal edges are below. They have only slight bends to conform the shape of the template. I’m only doing a 3/4 wrap of the edges in the tip and tail sections. This simplifies the build and the attaching of the edges.
This is the router I used to cut out the final dimensions of the p-tex base. The router bit has a bearing on the bottom that follows the shape of the template, thereby giving the base it’s shape. Even with a vacuum pickup on the router it still doesn’t capture everything.
Here the base (the long black shape) has been cut out. I fasten the base to the template using thin double stick tape is just a few places on the template to hold the base to the template so it doesn’t move while I’m cutting out the shape.
OOPS almost forgot the secret ingredient… 🙂 It “brings out the best” in everything!
Tonight I will cut the topsheet material and lay out all the material in reverse order to get ready for the layup. More pics to follow.
I took the day off from work tomorrow, so I’ll be pressing the ski first thing in the morning.
I got the skis in the press this morning. Couldn’t take pics while laying up the skis but here’s some pics I took last night of the materials laid out in reverse order:
Here’s the top sheet material:
Then the fiber glass:
The wood core. The white wood on the far end are wood (ash) tip spacers.
Another layer of fiber glass followed by VDS. VDS is thin strips of vulcanized rubber. They go over the metal edges and act as a sheer layer between the metals edges and the fiber glass.
So when the layup starts, the bases and spray glued to the metal cassette (just in the middle of the base) The cassette is 1mm sheet of aluminum. I guess I should have took pics of that……
Once the bases are attached, the rest goes as follows:
VDS over the edges, coat VDS with epoxy on both sides.
thin skim coat of epoxy
top cassettes (another 1 mm sheet of AL)
I tape the cassette together or use zip ties, then insert the cassette into the press. I start pressurizing the press to about 45-50psi. It looks like this:
I’ll press the skis for 10-12 hrs. Waiting is the hard part because at this point you hope everything has gone well. While laying up the skis something didn’t look right so I waited a bit for it to dawn on me. After about 10min I couldn’t figure out what didn’t look right unitl I poured on the first layer of epoxy. Then I saw what I forgot. I forgot to pre-bend the tips! Hopefully it won’t make too much of a difference now that I’m pressing at a higher pressure. Wait and see…….
I let the skis press for 10hrs, turned off the compress and then let them sit in the press over night. First impressions this morning look good. One core shifted slightly but I think I may not have placed it in the exact position. Shouldn’t be a problem since the ski is a full wood core and wood sidewall.
The top came out beautiful, no wrinkles.
Good edge fit in the tips. Looks like not pre-bending the base didn’t cause a problem. Although I still think it’s a good idea to pre-bend.
The tail and edge fit looks good too. The bases are relatively clean.
I’ll let the skis cure for a few more days before I start cutting the flashing off and the finish work. I’ll use linear poly-urethane instead of exterior poly.
I wanted to get the skis done for this weekend for our ski/snow board instructors meeting at Blandford Ski area since we’re supposed to be on the snow, but since it’s been in the 50’s – 60’s all week and no cold weather for the next 3-4 days. So there’s no rush to get them done, except to show them off… 🙂
No snow still, been warm in the 50’s all week. In theory we’ll be training on snow next weekend and the skis will be ready for it.
Flashing removed and ready for poly. I’ll be using System 3 linear polyurethane.
Update with pics:
I started the applying the linear poly-urethane. With the graphics being what they are I don’t think a decal will be noticed. So I hand signed them instead. The serial number is yymmddski#, I doubt you’ll ever see a ski# greater than 1 🙂
I’ll buff out the tops tonight, base clean up and mount the bindings.
I got the bindings mounted tonight and they are ready for the weekend!, assuming it gets cold enough for Blandford to make snow. We had another day of temps in the upper 50’s. Not good! Keeping my fingers crossed!
So a for all practical purposes the ski building part is over. I need to clean up the bases but that’s boring and not much detail to provide. Scrape off some remnants of epoxy, flatten the base w/ a file and hot wax.
I’ll give an update on how they skied as soon as I can. Stay tuned!
I was hoping to test the skis this weekend at our ski instructors meeting on saturday but the weather did no co-operate and we had no snow. Hopefully next weekend they’ll be enough snow to teach the new ski instructors and give the skis a test.
So I have some ideas for the next pair of skis I want to make in the next couple of weeks. I have some ash burl wood veneer which I really favor and some more but different skull material that is bad ass. For those that are following what do you think? My next ski will probably be a 175cm all around ski or a GS ski.
I fixed the comments section so anyone can post comments, just make them so everyone can read them. Here’s some pics of the burl and skulls for the next skis. Let me know what you think.