My first true homebuilt

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

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

Post Reply
Idris
Posts: 382
Joined: Wed Jun 29, 2005 3:34 pm
Location: Chamonix, France
Contact:

My first true homebuilt

Post by Idris »

Ok first a few thanks. To Skibuilders.com for putting the idea in My head Pat at PMGear for the materials and Davide for how to with next to no equipment and the vacuum bag.

These aren’t my first of home built. But they are my first pair of skis from scratch. Back in the early 80’s I did build a snowboard. I Laminated 2 sheets of ply to get my core/shape. Put glass on top and bottom from dads kayak repair kit and screwed on edges from a pair of old skis that were already part of a sled. The thing weighed 10kg (22lbs) or more and was impossible to ride but it was fun.

I cut up a pair of Powder plusses, re shaped and cambered to make the Spat-u-lette and a pair of Ghostoons – A pair of Pontoon like skis mad from 180 Phantoms.

Here I am routing my camber block. I used a pair of old Dynamics for rails to guide the router as they are 20mm thicker underfoot than tip/tail. I really should have put some side stops on my router bridge. The bit cuts straight through the ski edges but takes chunks out of it doing so :(.

Image

The cores are white aspen. Actually 188 bro model cores. I was trying to make some lightweight billy goating/AT skis. So I kept the Bro model sidecut and went with the dimensions of the core without tip/tail spacers or sidewalls. Giving me 170 length, 100mm tail 105mm tip and 85mm underfoot. With a pre made core all I had to do was bend the tips.

Image

I put the tip of the core in hot water (a pan full on the stove with the core held by a tripod) until they were soft and then clamped them in position.

I cut the bases using an old straight ski as a guide. Found this a real pain to do , even with a wide sharp blade, kept wandering all over.

Real getto budget clamps I know, but then all they have to do is stop the edge wandering off while the glue dries.

Image

Disaster – I put my bases up against my cores and they’ve done a nasty Durasurf trick and warped!

To combat this it put alignment blocks tip, tail and center on my mold. And then got drastic and drilled three holes in my core base and mold. These force the warped base to the right shape. And hope the core and glass will hold them true.

When trying to press warped bases at PM Gear I used this trick – well a variation of it. I would superglue the warped base into a the mold. The thing would bulge and bend all over the place. But once you had the edges glued into place in the mold it couldn’t escape. Then 175 F and 95psi would force it to comply and be a nice ski. This didn’t work if the base was too warped to force into the mold. Or if it broke free of the superglue before you got it in the press.

Anyway. I laid up my ski with what I think is 22oz triax with a few strands of carbon in it running lengthways on the bottom and 19oz (might even be 22) 0, 90 biax on the top. The glass was cast off end of roll from PMGear’s subcontractor in Québec. I had wrinkles in it and sharpie marks on it but it was free.

I used resin from www.epoxy-resins.co.uk. These guys were great to talk to. They had never had skis made with their resin but had loads of useful info about using their stuff and what it would stick to.
The only real mistake I made in layup was to mix too much resin at once in a heated (to make the resin more runny) cup and it went exothermic on me – almost caught fire, melted the cup into a mess!

I won’t be putting screws through skis to force alignment again – far too messy.

The press mold I had made was overkill. It wound be fine in a pneumatic press running at 100psi but you don’t need 25kg of wood for a vacuum mold.

Image

My pump is a humble fridge compressor. Out of shot is my vacuum switch. This consists of a large syringe a spring and a large micro switch. The spring and switch position are adjustable. I made this to stop the compressor burning itself out from continuous running.

Cardboard for breather fabric. Painters plastic on top and below the ski to keep it from sticking. Also packing tape on the bases.
They came out of the mold better than I expected. And way, way stiffer. Ok I was using the core of a much bigger ski than I was making but these things are stiff. I cut them out with a jigsaw using my balcony as a worktable to keep the mess out of the kitchen.

Image

I profiled the sidewall with a large file, haven’t manage to find a dovetail bit with a bearing in it and don’t have the room for a router table to make an angled table with a straight bit.
I sealed them with exterior wood stain (I had some lying around). Don’t do this. It works on the wood sidewalls but took 4 days to stop being sticky on the fiberglass. Also doesn’t look too hot either.

I took them out for a spin on the Grand Montets. They were as twitchy as hell…my fault, I mounted the binders too far forward. They really grip the hard pack. Even the shiny bits that everyone else was just sliding down . They do however suck in pow. Being stiff they are like old school straights and don’t float. They do bash straight trough any crud though.

Image

I have remounted the binders much further back – they have a good few cm’s of movement anyway being rental binders. And I’m getting them ground flat. Then it’s time to test again.
Image
kohlrabi
Posts: 26
Joined: Thu Aug 25, 2005 8:52 pm

Post by kohlrabi »

good work, Idris. I like how you've completed your project using what you had sitting around your house.

What are you planning next?

Where did you get your edges?
davide
Posts: 260
Joined: Wed May 04, 2005 7:13 am
Location: Tsukuba, Ibaraki-ken, Japan
Contact:

Post by davide »

Who is living in the apartment under your balcony?
Idris
Posts: 382
Joined: Wed Jun 29, 2005 3:34 pm
Location: Chamonix, France
Contact:

Post by Idris »

kohlrabi wrote:What are you planning next?

Where did you get your edges?
Something mellower and fatter.

I got my edges from PMGear...from one of their previous sub contractors, who no longer exist.

davide wrote: Who is living in the apartment under your balcony?
No one so far. It's a rental or holiday place. While cutting and sanding I had a big sheet of carboard stuffed under the railing to stop debris falling on the balconies below
Image
Idris
Posts: 382
Joined: Wed Jun 29, 2005 3:34 pm
Location: Chamonix, France
Contact:

Post by Idris »

Seccond go at skiing them - Skis now ground flat and waxed, bindings moved back 10cm.

Wow, different planet. No more grabby, nasty twitching. Skied very much like an old school straight ski. T

hey carve big arcs and grip like a good carving ski - no as well as a slalom carver that we had along to comare with.

Very quick edge to edge as they are very light and have next to no swing weight compared to most skis.

Still think they are way too stiff fine for piste but too straight for that.

Will probably sand off the top layer of glass and sand down the core a few mm and relaminate with some light er glass. Then again might just keeep them as they are for skiing nasty hardpack and ice.
Image
alexisg1
Posts: 110
Joined: Fri Dec 08, 2006 12:38 am
Location: Grenoble, FRA

Post by alexisg1 »

Now the snow has finally arrived, ou'll tell us ow it goes in da powpow ? ;)
Idris
Posts: 382
Joined: Wed Jun 29, 2005 3:34 pm
Location: Chamonix, France
Contact:

Post by Idris »

Deprived of their bindings they lie against the wall. The Spat-u-lette . Have the bindings -they were fun but slow this morning - reverted to Volkl Explosives for the pow (my Bro models are out on loan) - realy must get my next pair finished
Image
Post Reply