Mart's ski building adventure

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Mart
Posts: 21
Joined: Thu Jul 13, 2006 5:49 am
Location: Sherbrooke, Qc , Canada

Mart's ski building adventure

Post by Mart »

First, i've to say that this site is incredible. It has occupied my mind for several months now.

I have been looking at the content this forum for quite some time now without posting anything. I felt it was time to show a couple of pictures of what i've accomplished so far, before the final products gets done....

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I've decided to go with a pneumatic press design very similar to Buuk's (My mind was set before seeing your post. Still, i hope you don't mind. :) )

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The mold is made out of 42 pieces mdf. 14 for the camber part and 2x14 for the adjusteble tips parts. The mold is design to press one ski at a time without heat.

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The balloon is made out of low pressure discharge hose ( rated to 60psi). I don't plan pressing to more than 30psi so low pressure hose was ok. Plus it was pretty cheap at McMaster ( 2.?? $ / foot ).

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I think i might have a pair to show before the end of september. Will see how it goes.
Mart
Mart
Posts: 21
Joined: Thu Jul 13, 2006 5:49 am
Location: Sherbrooke, Qc , Canada

Post by Mart »

Sorry for the spelling errors.

You'll have to forgive my poor Quebec's English ( French canadian ).
Mart
Skivolkl
Posts: 22
Joined: Fri Dec 23, 2005 7:40 am
Location: Madison, WI

Good Work

Post by Skivolkl »

Everything looks good. I really like the blue cross pieces. What kind of material did you put on top of the MDF pieces on your base mold?
Mutombo
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Location: Madrid (Spain)
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Post by Mutombo »

Good work Mart. Didn´t you think about fixing the manometer after the air valve?
Mart
Posts: 21
Joined: Thu Jul 13, 2006 5:49 am
Location: Sherbrooke, Qc , Canada

Post by Mart »

The material on top of the MDF pieces is Masonite. It's very cheap ( 7$ CAN for a 4'x8' sheet of 1/8'' thick), it's flat but it hates humidity..... I might have a problem with that.

About the manometer... It will have to go. The gray PVC fitting is to big and I have a hard time fixing all the leaks because the hose becomes "too round" under pressure and neither silicon nor polyurethane adhesive can make a good seal that resist deformation. So i'll recut the hose, install only the valve and close the hose again.
Mart
Mart
Posts: 21
Joined: Thu Jul 13, 2006 5:49 am
Location: Sherbrooke, Qc , Canada

Post by Mart »

Things are going well.

My jig for profiling the cores is ready.

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I have remove the troublesome manometer and resealed the hose.

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And the edge bender is ready to flex some edges.

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Mart
Tore
Posts: 17
Joined: Sun Apr 23, 2006 2:07 am
Location: Norway

Sweet!

Post by Tore »

Nice work that is.
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zachjowi
Posts: 110
Joined: Sat Aug 26, 2006 10:41 am
Location: WI

Post by zachjowi »

hi I am a nOOb and I was wondering how long your press machine is.

thanks
Mart
Posts: 21
Joined: Thu Jul 13, 2006 5:49 am
Location: Sherbrooke, Qc , Canada

Post by Mart »

The lower piece is ±96'' long and the top is 6'' shorter. I use the small "lip" on the bottom to support the mold when it is outside the press.
Mart
Mart
Posts: 21
Joined: Thu Jul 13, 2006 5:49 am
Location: Sherbrooke, Qc , Canada

Post by Mart »

I've finish my first pair of ski this week. They have a couple of problems but i'm mostly happy with the results for a first pair.


Getting ready for the first layup.
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I took several minutes to fix the base to the mold but because of the low temperature, the epoxy was quite thick and the base shifted while I was spreading it ..... so i replaced it in 10 sec. Luckly for me it turn out well.
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Like most of us, my bladder has a couple of leaks and this could be a problem with this first pair. I'm working outside and its getting colder every day. The epoxy might not have had the time to cure completly in 24 hours.

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On the right, what i wanted my skis to look like. On the left, what they actualy look like. I hadn't thought the cloth would get dark from being "wet".

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The skis are semi-fat 120-87-115. The core is white ash. Wood sidewall. Fiberglass tipspacers.
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The white spots on the ski at the back are region where the top sheet is delaminating already. The cold outside temparature ( ±5C ) the night i pressed it slowed the curing of the epoxy leading to lost of camber and bad bonding of the top sheet. I should have waited more before flashing the excess material ans sanding the sidewall.
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Mart
Mart
Posts: 21
Joined: Thu Jul 13, 2006 5:49 am
Location: Sherbrooke, Qc , Canada

Post by Mart »

I've finished my second pair last week and had the chance to try them last night.

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I have used 34 oz triaxial fiberglass instead of 22 oz. I was hoping that the skis might come out stiffer but the fiberglass did not "wet" so well and i might have been scanty on the epoxy. In the end, they aren't that stiff and they have something strange about their behavior on the slope.

Sidecut is 116/75/102 mm. The tail might be to skinny compared to the tip. 180 cm in length.

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Among the numerous problems faced are : offset inserts (thanks anyway Bambi), delamination after flashing the skis, the bearing of the router slipped when bevelling the sidewall and a little bit of the wood sidewall chipped.

Still, i'm pretty happy with the results. Next time will be better.
Mart
plywood
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Location: wilen, switzerland
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Post by plywood »

the look cool! i like the different colours. how did you create those darker "stripes"? is it some sort of veneer shining through or what?
plywood freeride industries - go ply, ride wood!
Mart
Posts: 21
Joined: Thu Jul 13, 2006 5:49 am
Location: Sherbrooke, Qc , Canada

Post by Mart »

Yes, the stripes come from an exotic wood veneer (I've forgotten which).

The pale one has the original color and the red one was dyed with a water based dye.
Mart
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RoboGeek
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Location: Middle of a cornfield...

Post by RoboGeek »

good idea with the discharge hose! I've already located some near me thats 8" ID and 150 psi

good price on some 6" 150psi here:

http://heartlandpump.thomasnet.com/item ... 8?&seo=110
I used to be a lifeguard, but some blue kid got me fired.
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