:: View topic - Leaf Skis

First of all I would like to thank skibuilders.com and this forum for all the infos and help without which I would have never been able to make a pair of skis.

This adventure started this summer on the italian alps just under Mont Blanc discussing with some friends in front of a bottle of good Barbera red wine about the possibility of making a pair of freeride skis.

Yesterday we finished the first pair and we where really pleased with the result.

Leaf Skis Mk1 is a powder ski lenght 190 150-125-140 40 meters radius reverse camber.

Here are some pictures and links to Youtube videos with all the steps we went through.

Base cutting out on cnc

http://www.youtube.com/watch?v=TSL7XTumjXk

Core cutting out and shaping on cnc.

First we started with birch plywood but we ended up a little bit too soft to we changed for a bamboo core 10mm thick

http://www.youtube.com/watch?v=F9nPYe_csIk

For the edges bending we made a couple of tools

Edges gluing on base sheet with super glue

Laying up

Bagging and pressing

For the first pair we used a vacuum press but for the future we would like to build a pneumatic press

For shaping the camber we used a system similar to 333 one and it worked really well

Out of the press

Cutting out excess material

Sanding the veneer and grooving

Finishing with sealer/base/high resistence pu finish 10 gloss with uv absorber additive

Drying

The final product

LEAF SKIS Mk1

Leaf skis vs Volkl Kuro

Skis look like they turned out great.

I have a question on the graphics. It looks like you added them after the pressing. And then there is the pic where you are spraying the PU yet no graphics yet. How did you apply them?

Again, skis look great.

ra

I LOVE the look of the veneer topsheets. What kind of wood is it? It reminds me of a wood called ebony black and white.

Don't think you can get ^ that stuff in veneer form tho. If only...

Actually you are right.

For this first pair I placed some pre-spaced stickers after spraying the base and after that I sprayed the PU finish in order to protect the stickers.

For the future I would like to improve the process.

The idea is to cut out the graphics in the venner using laser and then put inserts made with a thin layer of aluminium supported with paper or TNT (tissue-not-tissue).

In the area where I live there are different veneer suppliers that can do the job.

The skis look great but I hope they will ride great as well

The solution is much easier and more environmental friendly.

I used multilaminar wood veneer.

In my case is a poplar veneer, stained in dark brown and white, re-pressed together and then sliced again.

Here's the link to the company that makes this sort of material:

http://www.alpi.it/uk/ListaProdotti.asp?IDSC=14

How did you go about making those nifty molds? I need something that thin so that I can just pop it into my vacuum bag. I can't figure out how you managed such precise bends on an aluminum? sheet. I searched the forum for another mention of this type of mold but had no luck.

That's a pretty neat way of making veneers. Are they very fragile?

For bending tip and tail of the aluminium plates I used an old metal plate bender.

It is made of 3 drums and an handle and according to the distance of the 3 drums you obtain different radius.

The aluminium is inside the vacuum bag and for the final camber setting I placed a piece of wood od 5 cm under the tip and 3cm for the tail while at the center I pushed the plates to the table using the "squeezer" you can see in the pictures (sorry I don't know how translate)

Not really fragile.

As fragile as oak veneer.

You can use them with radiuses up to 2mm.

If you have problems you can always support it on the back side with paper or tnt (tissue non tissue)

Here are some pictures regarding base preparetion and tuning

as I told you last week, great job Luca!

the first time I saw the skis I was really stocked.

Now we have to wait for a big dump near Mt Blanc, or we gonna drink tooooo much Barbera.

ciao

At the first look, I tought the topsheet was made with carbon fiber yarns...

You may buy pre-bent, sanded edges if you want to build many pairs, you will save a lot of time.

Thanks Davide you are right, the steel edges producer I contacted in Austria can give both the sanding and bending services.

At this stage I prefer the non bended ones because we are trying different side cut.

For example yesterday we came out with a new ski slimmer than Mk1.

We even tested a new press mould (still using vacuum) with better performance but that is still very fast to set up.

WE cut out with a CNC a base mould and a top one from the same sheet of 25mm mdf.

The aluminium plate with the plastic bag remains between the two moulds that are squeezed together.

Here are a couple of picture to explain.

And here it is the final result:

130-105-120 35 meters radius 1900mm lenght

Very small regular camber + rocker for the first 70cm

Looks amazing, I really like the look of that veneer.

What thickness of aluminium are you you using for the base mold?

4mm

Here are the last two skis finished.

One has a teak wood finish while the second is in ash.

We tested the teak one over Easter in LaThuile where we had 40cm of fresh snow saturday night

and they rided very well.

I'm really impressed by the finish! I'have alot to work on and learn!...

Wow, very nice and clean! What did you use for the core? Can you provide more details about the ski construction? How about the graphic? It's simple but nice and clean.

I read the earlier posts from page 1 about the graphic... Did you apply the graphic in the same manner this time? I've been looking into doing a simple graphic also but not sure if rice paper is the way to go just yet.

I may try printing a graphic onto transfer paper and them iron it on to cloth or on to wood veneer. My only fear is that if I apply the graphic to the top sheet before pressing and I get any kind of shifting of the top sheet the graphic will not be straight. Guess it's time to experiment.

Great Job!

Thi model is called Woodbones.

The core is made with bamboo panels 10mm thick.

The construction is the following:

1,4mm Electra 4000 base

vds rubber

750gr fiber

core

750gr fiber

finish veneer

The grahics are now made with screen printing as explained in skibuilders.com.

The process is the following:

After trimming the ski I sand the veneer and then I apply a layer of sealer and one layer of base.

Once is dry I sand again and I obtain a very smooth surface.

At this point I do the screen printing and after this I apply the finish.

In this way the graphics are better protected and the surface remains smooth without major jumps at the border of the graphics.

It is very important to use a very strong finish.

I suggest to use material that is normally used for parquet flooring varnishing where you need a lot of resistance to abrasion.

Thanks for the info. I will review the graphics process in skibuilders. I've been using an exterior polyurethane on my wood veneer skis and it's been holding up very well.

Mmm...what could I say....let me think...

WAOW !!!!!

amazing skis, simple process, nice graphics and awesome finish...

I'm a fan

claps...bis ...bis...bis..

awsome skis dude nice work...

Thanks. By the way I always go to ski to LaThuile in Valle d'Aoste.

If by any chance you come to La Rosiere/La Thuile you can try them.

This is a video made last Easter with Leaf Woodbones in action:

http://www.youtube.com/watch?v=UTgRIGt4feg&feature=player_embedded

Desmond, if you like the bc we have had over 6 feet of snow at the local hill since it closed 4 weeks ago. Skiing is better now than all season long here. Just got a ft+ yesterday. Unbelievable.

over 100" and counting as a base right now.

Wow! It's a shame to have all that snow go to waste. Our season was fair at best. The big snow storms missed us and the storms were more coastal storms, dumping 2 feet on Cape Cod.

Here we are back with some big news.

And when I say big I really mean BIG.

Last year we produced our skis using a membrane press with vacuum technology.

This worked pretty well but the pressure you can reach is only one bar.

For this reason we started a new project for building a standard air press.

Even for the cassette wea re thinking of something different and I will soon post the new idea.

Back to the press we considered the use uf steel H and C bars and it is made so that you can press two skis together using differend moulds (two floors press)

These are 1cm thick and this guarantees that it will not bend under any pressure you can possibly reach using air.

Pieces are welded

The only problem is the weight......600 imbarassing kilos.

Here are some picture of the new base structure.

[img]

Even for the cassette and heating system we are thinking about something different and I will soon post the new idea.

In particular for the heating system we would like to use hot water.[/img]

Good luck with the new press - I'm sure we'll see some quality results

Btw, can you recommend a brand of varnish to a fellow european

Definitely yes, I use Sayerlack products.

For the base I use TU160 + it's hardener

For the finish TZ 9010/00 + it's hardener

The base is not a big problem if you want you can even use an epoxy base and the cover with the PU finish.

A good point for the TZ finish is that it is very hard and not schrachable.

Not I'm trying even some natural finish like oils or waxes like paraffine.

I'm doing some tresting just to understand how it works in wet environment and I'll report soon.

Ciao

Luca

Hi,

I made it the opposite way, going from a mechanical press with air bladder to some vaccuum system.

Looking at your skis, you were one of those who inspired me. What made you change of system ?

I understand your concerna about pressure, but did you manage to make links between the skis you made and the fact that you were using vaccuum ?

In one word, does vaccuum make worse skis ?

add : one of my friend combined vaccuum and mechanical press, awesome results

Well, I think that vacuum press makes good skis but with a bladder press should improve quality drastically.

Although it is quite difficult to heat a vacuum press.

All this is coming from reading ather post and experiences on this we site.

I think that combining a vacuum and mechanical press is a great idea in particular if you want to do a cap construction.

Anyway this winter in Valle d'Aosta will say if I'm right or wrong.

Ciao

luca

Luca,

Thks - I've been putting my topsheet ideas on hold because it was making my head hurt.

Cheers,

Rich.

Thx for the answer Luca.

I've just pressed my skis. See below :

I am really happy with the result, but haven't skied them yet.

The thing is, I really dopn't understand how a mechnical pressure is better than vaccum. It should be all about pressure by surface...and vaccum is unbeatable (unless you have a bad vaccuum system).

I'm not good at physics, but I understand that if you reach 0bars in absolute, or -1 bar in relative, the pressure is the highest you can get, and you'll never be able to reach that pressure/surface with a mechnical press.

Does the mechanic have an effect on materials that I do not understand ?

Sorry to use your post to tell my story, but I'm very looking forward your tests.

This is exactly same design I was going to build. You will hear from my patent lawyer

http://www.skibuilders.com/phpBB2/viewtopic.php?t=2588

How toll it is? Footprint looks narrow. In metal fabrication (I was told) height equals wight or at least 3/4 of it. 1200 lb not bad, mine probably over 1ton and can be wheeled around by one person.

haha this made my day.

The press is 2 meter tall by 1 meter wide.

Actually I'm not an engineer but I tried to push it to see if it could be turned over and I couldn't move it one cm.

I think you are a little bit wrong.

I'm not good at physics as well but what I understood reading this forum is that with vacuum you can get a pressure of 1 bar while with air under pressure (fire hose system) you can get to 7/8 bars.

In order to improve vacuum performance you should use an autoclave.

If you lurk a little bit the forum you can find a lot about this.

As soon as we will be ready I'll definitely post my first impresions and experience differences between vacuum and air.

Ciao

Luca

Hi here are somo picture of the new press.

The press and the stell mould work great and results are definitely much better than vacuum pressing.

The mould is made by a 3mm stell plate and an other layer of 2mm laser cut bolted to the 3mm one. Using this system eliminated any problem with edges and during layng-ups.

While this is the press. The heating is done with hot water that flows into an aluminium bar with holes in it.

This is a glossy picture of the press in action

This a video of the cnc milling the bamboo core:

http://www.youtube.com/watch?v=GlWOPnRGszQ

While this is the final result:

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Excellent! Are you in production now?

Beautiful skis!

Hands up if you want a pair!

Yes, we are making around 20 pairs per type (actually two) to see if there might be a small market ready for this sort of skis.

The wood finish is really natural and simple, let's see how it goes.

We even set up a small web site because we would like to do direct sales but in Italy it's not that easy.

The web site is in italian but within next week the english version should be up and running.

If you want to give a look the address is:

www.leafskis.com

Consider that all the pictures are made by us.

Ciao

Luca

Wow, great looking skis! can you elaborate on your water heating system? How are you holding down your wood on the CNC machine, vacuum?

Thanks!

That is awesome!!

One question: what are you using for mold release and how are you going with not getting epoxy stuck to your cassette with the two parts fixed together idea.

Again awesome press and skis!

Actually two questions: You guys have "day jobs" in the woodworking industry as I recall, and from all the nice toys you have (eg CNC).

Having been lucky enough to see these skis in person. I can only say they are of the highest quality - finish - attention to detail, etc. that I have seen anywhere. Absolutely flawless

Hi Idris

It was a pleasure to meet you yesterday in Camonix.

I hope to see your skis with the new finish posted soon.

Ciao

Luca

For the heating system we used an aluminium bar that has 8 longitudinal holes.

In 4 of the I have water going in and on the other I have water going out.

Temperature 80 Celcius.

For the cnc i confirm we use vacuum

The steel cassette is teated before every press with "non sticking liquid" (forgive me for the translation). Actually it is a sort of liquid wax into a very volatile liquid that you distribute on the cassette with a sponge.

Yes we are in the wooden industry (doors http://www.castiglioni.net/default.asp ) and this makes things much, much easier

Great job, really. These are beautiful.

Hi Luca,

You mentioned testing more natural finishes in an early post. What option did you go for in the end?

Rich

Hi Rich

Last year the cycle we used was the following:

sanding+sealer+sanding+PU base+light sanding+PU finish.

The finish was great but not so natural.

We changed and now the cycle is done in this way:

sanding+sealer+sanding+finish

Avoiding the base allows to the grain to be seen as if it was treated only with wax.

The vanish I'm using is from Sayerlack:

http://www.sayerlack.it/scripts/default.asp

The codes are:

TU160 + it's hardener for the sealer

TZ 9010/00 + it's hardener for the finish

The finish in particular is fantastic because it is very hard with a 10 gloss finish but it really leaves the wood grain very natural.

Hi everybody

We did some changes on the Woodbones in order to reduce the weight.

With the standard bamboo woodcore the weight was 2400 grams per single ski.

We made a test ski with a red cedar woodcore with bamboo sidewalls and we reduced the weight to 1850 grams.

This means more than half a kilo.

This w/e we will test them on the snow, hoping to find some fresh powder that this year on the alps looks like a mirage.

So the Actual ski construction steps are the same as the "HowTo" section, even if your using the Vacuum press method? I am building a vacuum press and Skis in less than 3 months. So any and all help would be very appreciated!

Wonderfull work! I've seen some of your skis last winter in shops in Italy

(Alta Badia I guess) - they are really beatifull!

I was wondering what thickness of veneer do you use 0,6mm, 1,5mm or different?

At the shops I found they have only few veneers 1,5mm and those 0,6mm are really thin...

I think the majority of use are using the thin stuff.

The veneer I've been using is 1/42"=0.6mm.

I think if you use the thicker stuff it will crack where it bends.

sam

no way it will crack - I've made some tests with 1,5mm maple - it bends a lot, with no problem!

but anyway - good to know that most of you use the thin stuff - it would make it much easier as it's more choice in that thickness.

Don't forget that the veneer is not just pretty, it will add stiffness to your ski not to mention weight. IMO the thinner stuff is a better choice.