When I had spoken to the technical people at west systems epoxy I had aske d them how I would know at what presure to press my ski`s. they had told me that my goal should be to have a 39 percent epoxy to fibre ratio. 39 percent?! Are you sure this is what they told you? Maybe it was 39 percent fibr...

It could be welded (in the materials science sense) together with a solvent. Application of a slovent at the edges of the pieces will open up the molecular chains of the material. When two pieces are put together the chains entangle and once the solvent has evaporated/boiled off you'd be left with a...

May I suggest you reconsider? PLA in any form (PDLA, PLLA or PDLLA ) is DESIGNED to break down when it gets in contact with water! One of its uses is as tissue scaffolds for cartilage replacement. The idea is that the open cell foam allows nutrients and cells into and out of the region. The cells at...

When you mount your ski measure the centreline position with a tape measure and base your mounting points on that. Don't trust the markings!

Park skis and pipe skis are starting to go on divergent paths. There a lot of 'pure' park ski coming out in the next season and they're already a few out there. The new park skis are going reverse camber in the tip and tail so that they easy to butter and spin off the tips/tails. E.g. armada alpha o...

Nice! Thats the sort of thin I had in mind. Well, if people think it will be of help I can put something together explaining Classical Laminate Analysis (CLA). It might look a bit tedious and may feel like going back to school but it could be pretty useful for ski design. One of the things CLA gener...

Go to matweb.com and like up the wood and natural products category; its got data for 368 different materials/woods! For the GFRP use NCF rather than woven material if you can; its a hell of a lot easier to model! Ideally you'd use UD prepreg to make the layup as its easy to model and all the data y...

All that talk about sandwiches made me hungry! :) Just kidding. Alex - I'm impressed by the people who understand how a ski should be made and can show it mathematically and can express changes in the ski composites mathematically. It's nice to know (generally speaking) a head of time what the chan...

I've put together a short document on bending of sandwich beams. I've put in a couple of examples too. As this thread started on the subject of a ski with composite only on one side of the core I did examples for this, a core by itself and a core with composite on the top and bottom. Hopefully this ...

I just noticed that son of sinecure's (tgr) skis were built by 333 with 12oz bias glass. For a resort skier is this even safe? Am I overreacting to think that skiing these as a resort ski is dangerous? I know for touring skis people are going that light, but for ripping bumps and jumps, etc??? Depe...

Rubber is about the same density as epoxy so shouldn't affect the density of the material whether it phase separates to form an new phase or whether rubber chains and epoxy from a co-polymer. If the rubber is added as a separate layer then it doesn't need to be very thick to have an effect so a thin...

I'd guess at a plastic foam reinforced with a natural fibre (wood, jute, hemp etc...). The foams would probably be some sort of polyurethane system as that is the most well researched matrix for short fibre reinforced foams. Corks was one of my first thoughts but it looks too floppy. Also, I noticed...

I've always wondered why horizontally laminated cores don't seem to be used. Yes, the layers in a horizontally laminated core might seem like obvious sites for delaminations to occur. But, the strength of the joint between two pieces of wood glued together will be much stronger than the wood itself ...

Young's modulus along fibres: 20.6GPa Ultimate Tensile Strength along fibres: 193MPa UTS transverse to fibres: 8.1MPa UCS along fibres: 68.4MPA In-plane shear strength: 9.2MPa From: Mechanical Properties of Bamboo, a Natural Composite, S. C. LAKKAD, J. M. PATEL, Fibre Science and Technology 0015-056...

knightsofnii got the right idea: "Your resin is a good source of dampening properties. Lots of people choose resins with "rubber modifiers" added to them or something like that. Roy (RIP) at QCM explained to me to NOT go with something that contained rubber added into it, but I think ...