Types of wood

[Inbred_Redneck]

Alright this is a question regarding the wood properties chart here ---> http://http://www.skibuilders.com/howto/skicon/woodcore.shtml

Im confused as far as the elasticity and rupture goes. If the numbers are higher, then does that mean they are stronger and more stiff?

Also what kind of wood do you guys use in your cores?

 

[camohard]

That's right; the higher the modulus of elasticity, the harder it is to bend and the higher the modulus of rupture, the stronger it is. I have been doing some tests on different wood to come up with the best combination, but I've sort of ruled out maple (a lot of people like it though, including LINE, so who knows). Douglas fir looks pretty good but there might be some problems with binding retention. The guys on skibuilders.com have had a few problems with that, and they're mostly freeheeling and touring, not puting a lot of stress on the screws. Id get some scraps and also do up some test skis with whatever you have around to see what you think. Im just waiting for my press to get welded up and my materials to get shipped, so I cant say from experience what will be the best for skis. if you have a good wood supplier, tell them what youre doing and what they think; they probably will recommend some weird sounding stuff (which might actually turn out pretty good), but more importantly, they can tell you more about how to understand all those numbers as well as the impact of grain length, orientation, etc.

 

[crunkasfuck]

Common Name

Modulus of Elasticity (kg/mm2)

Modulus of Rupture (kg/mm2)

Density (g/cm3)

Ash, black

1126

8.97

0.526

Ash, blue

984

9.82

0.603

Ash, green

1170

10.04

0.610

Ash, white

1249

11.01

0.638

Aspen

838

6.04

0.401

Birch, gray

797

6.88

0.552

Birch, paper

1119

8.79

0.600

Birch, sweet

1520

11.81

0.714

Birch, yellow

n/a

11.88

0.668

Fir, balsam

879

5.42

0.414

Fir, silver

1076

6.69

0.415

Maple, black

1141

9.37

0.620

Maple, red (soft)

1155

9.35

0.540

Maple, silver

805

6.34

0.506

Maple, sugar (hard)

1290

10.97

0.676

Poplar, balsam

716

4.76

0.331

Poplar, yellow

1058

6.52

0.427

Spruce, black

1069

7.24

0.428

Spruce, red

1071

7.15

0.413

Spruce, white

1001

6.38

0.431

This may be of some use?

 

[crunkasfuck]

Modulus of Elasticity (kg/mm2) stiffness

Modulus of Rupture (kg/mm2) strength

Density (g/cm3) weight

 

[goneforever]

It depends on what type of ski you are making. If you are making a jibbing ski, you would want something softer; if you are making a charging ski, you would want something stiffer.