First Ski Build - Success!!!

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chrish118
Posts: 10
Joined: Wed May 06, 2015 8:15 pm

First Ski Build - Success!!!

Post by chrish118 »

Hey Guys,

Just finished up my first pair of skis, and I wanted to say thanks to everyone on this site that provided all the helpful info to make it happen. I'll post a few pictures below of my process, but will mainly talk about the stuff that I had issues with along the way, so hopefully some of you can avoid my same mistakes. If you have any questions please send them my way.
Chris
Cheyenne WY

chrish118
Posts: 10
Joined: Wed May 06, 2015 8:15 pm

Post by chrish118 »

Difficult parts of the process, for me:

1. Sidewall comes detached from core during planeing

2. Core/base alignment during layup

3. Smooth edge bending

4. Beveling sidewalls after deflashing
Chris
Cheyenne WY

Hayden.Cameron
Posts: 7
Joined: Sun Oct 05, 2014 10:46 am

Post by Hayden.Cameron »

I have issues with the sidewall too. I found I can get pretty good bonding using ABS that has been sanded, cleaned with alcohol wipes, flamed and cleaned again and using Gorilla Glue. Getting even glue application and clamping force is the key to preventing the sidewall separating.

I am profiling the ski on a router table so slightly different to planning.

What did you do to locate the core, base, etc when laying up?

skidesmond
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Location: Western Mass, USA
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Post by skidesmond »

To keep the base in place during layup I use a 3M spray glue. I spray just a small bit under the center of the base. The rest of the cassette is waxed so the epoxy won't stick nor will the 3M spray glue. On the rest of the cassette I use left over bits edge, a couple of inches long. Using a super strong 3M double stick tape I align the small edge along the base and tape it down. The 3M tape will stick even tough the cassette is waxed. I'll do this is 2 or 3 places on each side of the base. That keeps the base from moving side-to-side. The 3M spray keeps the base from sliding front to back.

Use caution with the edge guides. You don't want it to slip under the base.

Lots of tips for smooth edge bending in the forum so I won't go into that.

I use wood sidewalls.

Core alignment... I don't do anything special except use caution when placing the core in place. I've tried using alignment guides like I do for the base but not anymore. You need to be real careful the alignment guides don't slip underneath the wood core. I press it down to make firm contact w/ the FG underneath it. Having a stiff cassette (AL 1.5mm thickness or more) also helps. When you lift the cassette to place it in the press you have less bending of the cassette and less likely that the layup will shift.

Good luck.

heke
Posts: 113
Joined: Sun Dec 06, 2015 9:44 am
Location: Europe

Post by heke »

skidesmond wrote:To keep the base in place during layup I use a 3M spray glue. I spray just a small bit under the center of the base. The rest of the cassette is waxed so the epoxy won't stick nor will the 3M spray glue. On the rest of the cassette I use left over bits edge, a couple of inches long. Using a super strong 3M double stick tape I align the small edge along the base and tape it down. The 3M tape will stick even tough the cassette is waxed. I'll do this is 2 or 3 places on each side of the base. That keeps the base from moving side-to-side. The 3M spray keeps the base from sliding front to back.

Use caution with the edge guides. You don't want it to slip under the base.

.
When you use the spray glue, do you tape the area that you will glue or how do you keep it wax free? As fas as i know it is usefull to wax the ski base also? Do you have the wood core pre made so that it is little smaller that the ski base?

skidesmond
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Location: Western Mass, USA
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Post by skidesmond »

I have the area on the cassette marked off w/ a sharpie pen. Yes I wax the base also with a very very thin layer. Leave a spot on base wax free. Don't tape the area on the cassette. Believe it or not the tape will make an impression on the base when you press (been there, done that :) ).

The wood core with it's sidewall is about 8-12mm wider than the base.

twizzstyle
Posts: 2203
Joined: Tue Mar 07, 2006 8:25 pm
Location: Kenmore, Wa USA

Post by twizzstyle »

1. Sidewall comes detached from core during planeing

Yep, welcome to the club. This is difficult for many people. Some folks have found good success. I profile my core/sidewalls together on my CNC router, by covering the bottom with masking tape then spray-gluing it down to a piece of MDF that is clamped to the router. The key is keeping the sidewall from lifting at all, if it lifts even a tiny bit it will rip right off. A vacuum table might work too. Also, some people profile the sidewalls separately, then attach them to the core during the layup.

2. Core/base alignment during layup

I drill two holes in the core, cut two tiny pieces of wood dowel the same thickness as the core, and superglue those to the base. Then the core just slips over those during the layup, and won't move. It does mean I have to cut holes in whatever composite layers I have below the core, but that's easy.

3. Smooth edge bending

Tile nippers. Do a search. Easy.

4. Beveling sidewalls after deflashing

What part of this is causing you problems? This is like the easiest part of making skis?

chrish118
Posts: 10
Joined: Wed May 06, 2015 8:15 pm

Post by chrish118 »

Lots of good advice... on my next pair i'm definitely going to make some improvements.

1. With the sidewalls I used wood glue and clamps to secure. They seemed really solid until I got down to 2mm thickness then the tips would come detached. Wasn't a huge issue but next time i'll take the advice of securing with tape from below as well during the routing/planing.

2. For core alignment I ended up gluing vertical plastic cylinders that matched holes drilled through the base. This worked great for alignment but was a little bit of a hassle forcing the fiberglass around the alignment pin. I will work on some exterior alignment guide next time.

3. For the edges, I had a plank of wood with a screw/washer setup that I would use as the fulcrum for the bend. This and a pair of pliers worked decent, but per your advice i'll invest in a pair of tile nippers next time.

4. Beveling should have been easy, but for some reason I had issues. I used a vertical router bit and a angled wedge guide that I would run the ski along to bevel the edge. The issue was that the router bit needed to run on a clean metal edge in order to bevel accurately, and I hadn't cleaned the edge well enough before going to the router. Another difficultly was putting enough pressure on the ski to eliminate the camber while I pushed it through the router setup. Any ideas on this?

I'll load up some pictures as soon as that ability is granted to my account.
Chris
Cheyenne WY

chrish118
Posts: 10
Joined: Wed May 06, 2015 8:15 pm

Post by chrish118 »

vacuum pump
Image

base ribs
Image

base form
Image
Chris
Cheyenne WY

chrish118
Posts: 10
Joined: Wed May 06, 2015 8:15 pm

Post by chrish118 »

router sled planer
Image

edge gluing
Image

ski design
Image
Chris
Cheyenne WY

chrish118
Posts: 10
Joined: Wed May 06, 2015 8:15 pm

Post by chrish118 »

applying pressure
Image

fresh off the press
Image
Chris
Cheyenne WY

chrish118
Posts: 10
Joined: Wed May 06, 2015 8:15 pm

Post by chrish118 »

final product
Image

with bindings
Image

So far they are going strong, skied on them 15 times with no noticeable relaxation of camber of delamination. The only damage i'm noticing is the topsheet/sidewall edges seem to wear faster than production skis. They are getting pretty chipped up along the tip/tail edges from ski-to-ski contact.
Chris
Cheyenne WY

heke
Posts: 113
Joined: Sun Dec 06, 2015 9:44 am
Location: Europe

Post by heke »

Hi Chrish,

nice looking skies. What is thickness of plastic you have in the mould?

Is it polykarbo plastic or ? I have 2 mm polykarbo-plastic, I think it is too soft with support system you have.

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Akiwi
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Location: Olching (Near Munich) Germany

Post by Akiwi »

Congratulations on the first success.

I am also surprised that the press can create flat bases. I would think that you would need something under the Playcarbonate to spread the load a bit more.
I am nobody. Nobody's perfect, so I must be perfect.

twizzstyle
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Joined: Tue Mar 07, 2006 8:25 pm
Location: Kenmore, Wa USA

Post by twizzstyle »

Looks like he's taping his bag to the mold surface, so there really isn't any load pushing the polycarbonate down between the ribs. The atmosphere is pushing on the bottom just as much as it's pushing on the top. I'd still want more ribs though, just the weight of the materials may be enough to make it sag?

For the sidewalls, you nailed it - get your edges completely deflashed and smooth before routing. I put my skis in my tuning vises, which puts the ski on its side, and route each side like that. No need to push out the camber, router runs on the base, bearing on the edge.

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