Shopvac's Skis

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plywood
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Post by plywood »

me too! looks really nice.
how do the wooden topsheets hold up? in terms of "topsheet chipping" and other damages due to bashit the sidewalls with the edges of the skis while skiing?
plywood freeride industries - go ply, ride wood!
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shopvac
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Location: Colorado

Post by shopvac »

Thanks for the comments. The veneer does look really good after it gets finished. I think the veneer is slightly less durable then some of the other topsheets the big companies are using. My atomic TMEX's are 5 years old and they look really good still. They are the orange ones with a cap construction so that might help. My other skis are a pair of Praxis Pow 195's and the topsheets on them look pretty good after 50 days of hard skiing. They are scratched and chipped a little but nothing terrible. I don't think the veneer topsheets on our new skis will be much worse.

So far my brother and I really like our skis. We have been on them in all sorts of conditions ranging from corn, to crud, to powder. I prefer powder.
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shopvac
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Post by shopvac »

We finished the fourth pair of skis and they just keep getting easier and cleaner. This pair is the same as the last two pairs we have built. They are for a good friend. He came over and built them with our guidance and help. We used a thin coat of epoxy on the topsheets which we have not done yet. I think it worked pretty well but it did leave some small bubbles on one of the skis near the tail. Maybe we left a little too much epoxy down there or something. I am not sure why there were bubbles down there. Aesthetically, they still look stunning with the aspen topsheets in my opinion.

edges are on almost all the way down the ski:
Image

Materials are ready to go:
Image

small wooden dowels are super glued down to the bases for alignment:
Image

laying the last fiberglass on the top of the wood core:
Image

The ski is in the press:
Image

the final product with some sth14's:
Image
dbtahoe
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Post by dbtahoe »

Has to be one of the most successful "Outside the Box" projects I've seen here over the years. The easier and cheaper you can keep this hobby the better. I find myself getting so caught up in the process, that I never get anything done. How has the cloth been holding up? I know early on you were having ripping problems. Did the new fabric solve it. What do you think of webbing? Maybe another use for firehose.

Cheers!

P.S. Diggin' the wood cat-track!
rockaukum
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Post by rockaukum »

I noticed that you are not doing the full wrap edges. Also in doing so you pre shape the base. How is it that you finish the ski? Are you just free hand cutting the flash to the base? Do you use a template of some sort? Let me know as this is my chosen path for the next ski. It seems it would be easy to just let the base and all other materials run long and finish with a trim to the desired shape? Any other input?
ra
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shopvac
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Post by shopvac »

The bases are cut out with a router before we attach the edges. The template we use has notches where the edges sit recessed 2.2mm. When the ski comes out of the press we flash the ski with a band saw. We are leaving around 1-5mm of flash around the entire ski. You may be able to go right up to the edge if you are better or more confident with a band saw than we are. Then all you would have to do is do a little belt sanding and you could be finished.

We then clamp the ski on top of the 3/4" MDF template with the edge of the template matching the edge of the skis metal edges. The base of the ski is down and the topsheet is up. Then we use a pattern bit with a ball bearing on the bottom of the bit to route the skis to have straight sidewalls. This only works for the running length of the ski because the tips and tails of the ski get to be too far away from the template to be able to use the router bits length. The ski is bent and the pattern is flat so we can't go all the way around currently.

To finish the tips and tails we clamp the ski in a vice we have mounted on the workbench and belt sand the tips and tails to the right shape. This usually is done by taking the flash down to match the base material which is cut to be the finished shape we wanted initially. Sorry, I don't have any pictures of any of this but next time I will try and get some (this may be a while though as we don't have plans to build anything this week).

Yes, all of our materials stick out over the edge of the ski. We try and minimize the amount all of the materials stick over the edge because it seems easier to flash.

dbtahoe -- thanks for the comments. We would be nowhere without Montuckymadman and his crazy sewing skillz! the new fabric is totally the ticket. We have pressed 6 times with the current bags and they are "knock on wood, do it" still running fine.
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MontuckyMadman
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Post by MontuckyMadman »

blow um up man! how high can you go?
brewster
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Post by brewster »

Do you punch holes in the bottom fiberglass for the dowels? Or just try and wrap around them?
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shopvac
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Post by shopvac »

Brewster -- yes we do cut holes in the bottom fiberglass layer with a pair of scissors or a razor blade (whatever is laying around). We try and remember to do this before we apply epoxy for obvious reasons but sometimes we forget and it isn't a big deal.

Montucky -- So far we haven't tried to blow them up. We have had them up to 45psi and usually press just below that. Maybe we can send you some more base material and you can make us another pair. I will pm you.
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shopvac
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Post by shopvac »

Here is a short 2 minute time lapse video I put together of our very first pair of skis we built. This was back when we used to have a dual ski press and a canvas cloth frame. Youtube stripped the music so it isn't as interesting.

http://www.youtube.com/watch?v=a4AMjXalupo
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chrismp
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Post by chrismp »

great video guys!

i'm planning on using a press frame from MontuckyMadman as well :)

i have just one question...in your video it looks like the fabric stretches out quite a bit under the pressure of the bladders. is that just some slack in the tubes or does it really stretch? (i guess that would reduce the actual pressure on the ski, plus my bladders aren't half your diameter)

i've heard that this kinda fabric only stretches out in one direction, so maybe it wouldn't stretch if the tubes were sewn lenghtwise (i hope you get what i mean).
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MontuckyMadman
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Post by MontuckyMadman »

The cordura has a unidirectional weave. Virtually no stretch at 50 PSi but then my top mold cracked cause I did not heed the words of mighty plywood and transfer the stress in a directional/downward manner instead of out to the sides. Live and learn.
Cordura is bombproof.
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chrismp
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Post by chrismp »

thx montucky!

i'll get back to you as soon as i have the molds ready...the bladders are up and running already (without any sealant!).
now it's on to the molds.
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shopvac
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cloth press frame

Post by shopvac »

Chrismp -- The blue cloth in the video is the old duck cloth that eventually ripped a couple months ago. That blue stuff was basically the same fabric that carhartt jeans are made with. The gray/silver looking cloth we have been using lately is the 1000 cordura nylon fabric that MontuckyMadman so graciously supplied. It has proven to hold up very nicely.

Montucky -- can you explain how your top mold cracked in more detail? Any pictures? This could be very useful to anyone who plans on building a cloth fabric press frame style ski press.
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chrismp
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Post by chrismp »

plywood wrote:awesome, so glad that it worked out for you too!

my biggest concern was that the mold could snap in two pieces lenghtwise if you build 2 skis at a time. but i think your 2x6 really helped prevent this.

i made a little illustration ;)
Image
version A is a regular, flat mold for two skis. yellow things = firehoses, blue = clothen tube.
so if you inflate the hoses there results a load on the clothen frame. on the outsides it`s no problem as the cloth takes up the load. the problem lies in the middle. there the mold has to take all the resulting load as there is no cloth that could hold the two parts of the mold together. so there is some sort of shear force in the molds itself.
version B shows the better way to do it. by adding some 2x6 or whatever on top and bottom of the mold you can take up those forces in the middle and pass them on onto the cloth frame. this should really reduce the shearforces in the mold and prevent it from snapping in two pieces.

but in general clothen pressframes are sweet. they can be a bit bitchy to load, but they are cheap, light and do their job pretty well.

...i think i should patent my great and glorious invention and start earning millions with it ;)
Montucky already told me about his cracked mold...it's the same problem as plywood describes in the quote above.
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