sidewall and planing to profile

[MontuckyMadman]

I'm interested in these phenolithics. Used in high end consumable table tops for cnc machines and now available through isosport and in various formulations in the US. Looks like dynastar is using this for sidewalls in one of there most popular models of all time.
Excellent elongation at break, very dense and hard but extremely malleable and flexible.
Its not cheap but its made of natural material in a composite structure.
Should be good for bonding and everything sidewally.

[Sherpa Burns]

Ipe is a very tough and durable wood, but I would advise against using it. It is very heavy. In all likelihood, with even a 1/2" sidewall, you could end up with sidewalls that outweight or come close to outweighing the rest of the ski combined. We built a deck with this stuff and it is very heavy.

[Richuk]

Sam, I'm a fan of maple too, but had a few issues when routing. I guessing the spiral router bits ensure this is not a problem - difficult to find in the UK.

MM, the product in the UK is known as tufnol, been around since the war. I'd be surprised if Dynastar were using this as sidewall material - it can't be mistaken for wood and doesn't contain melamine. I would advise against the paper based tufnol, it will saturate over time. A fibreglass infusion is available, but it is super dense.

Personally, I took this in a different direction and it does its job well.

[SHIF]

Ipe is a very tough and durable wood, but I would advise against using it. It is very heavy. In all likelihood, with even a 1/2" sidewall, you could end up with sidewalls that outweight or come close to outweighing the rest of the ski combined. We built a deck with this stuff and it is very heavy.

These exotic hardwoods are only slightly higher density than UHMW polyethylene:

Ipe = .038 lb/in3
Massa = .036 lb/in3
UHMWPE = .034 lb/in3

Therefore, for all practical considerations they do not add significant weight to the ski (versus using plastic sidewalls of similar dimensions). And since they add to the flexural stiffness of the core assembly, you can use a slightly thinner core profile geometry, therefore their use may actually result in a lighter ski of similar flex characteristics.

Maple and bamboo have less density than these other materials, so when used as sidewalls will also yield a lighter finished ski.

Cheers,
-S

[Anvil]

Is anyone using a large drum sander to profile their cores with sidewalls attached? Severl video look like the cores are profiled this way, Never summer and swell planks. If anyone does this, how does it work and how large of sander is required.

[MontuckyMadman]

we use an enormous industrial over head belt sander and it works better than any other method I have tried. Its 3 phase and mounted in place and has a shop sized dust collector with it also, conveyor belt for moving the sled through. Its like a $30K machine.
Look in the journals a guy built one for kite board cores on here.

[Jibber]

Me

I pour my sidewalls with a mix of epoxy and cotton-flakes. It is no problem to sand them with my thickness sander.

I don't know if it works with ABS or UHMW-PE but if you can sand them down with a belt sander it should work.

Cheers, Christoph

[grace ski]

We do it like this:
CNC or waterjet cut the sidewall profile out of .5" UHMWPE with it rotated 90 degrees
take the piece and rotate 90 degrees to attach to core
we use ZIP ZAP to tack it to core
we drill small 1/32" holes to seep epoxy between the core and sidewall

the extra sidewall that over hangs the edge is cut off in post press finishing

www.skigrace.com

dwl