Jump to content

Wood


John E
 Share

Recommended Posts

Does anyone know what considerations board manufacturers use to decide what type of wood to use for board cores?

I know that one local (non-alpine) board manufacturer uses Aspen. I thought this was strange. I would think that if cost were not an issue, a designer would choose wood with the highest strength -to- volume ratio. I doubt that would be Aspen. I would think it would be more like Maple, Birch, Spruce, Ash, or ???.

I would think a good board core should be stiff, thin, light & be able to be deformed to a large degree without breaking.

Also, do any board makers employ horizontal laminations instead of vertical? If so, what are the advantages of each?

Link to comment
Share on other sites

maybe a bamboo core, lite metal top sheet and a carbon butterfly over it.

That sounds pretty expensive to me; just think prior WCR metal plus Madd...

...but sending your kids to college is overrated, anyway.:lol::lol::lol:

Link to comment
Share on other sites

It sure seems like if you were to laminate with the grains accross each other it would stiffen it up torsionally. Maybe not 90* to each other, but for example grain heading from roughly the left leading edge to right trailing edge and then the next lamination would be right leading edge to left trailing edge.

I should really make myself a snowboard press...

5 bucks says I have one before I no longer can snowboard.

Link to comment
Share on other sites

I thought about this a little more after I posted.

I recall that 10 or so years ago, some makers experimented with foam cores. Evidently, these didn't work because you don't see them any more.

The strength to volume ratio of foam would be very low. The laminations that give the board the majority of its strength are the outer layers - fiberglass and or carbon fiber. The core serves to separate the outer layers. The farther they are from the central (neutral) plane, the stiffer the board. So, the core could easily be foam if it didn't break down. Maybe that's why foam was abandoned - it broke down under flexing.

The core should withstand flexing to extreme deflections without breaking. It just needs to keep the top & bottom laminations separated.

I wonder how balsa would hold up (probably not very well)?

Link to comment
Share on other sites

Well For the high end world cup level Racing Board manufacturers its not the amount of different products they use. SG Boards for instance use a Poplar Beechwood core. Its not a thick sheet of wood but a thin sheet combined with titanal. Figuring out how to combine the wood and metal in certain parts of the board is unknown and that is why Kessler and SG Are miles ahead in the race industry.

Link to comment
Share on other sites

I thought about this a little more after I posted.

I recall that 10 or so years ago, some makers experimented with foam cores. Evidently, these didn't work because you don't see them any more.

The strength to volume ratio of foam would be very low. The laminations that give the board the majority of its strength are the outer layers - fiberglass and or carbon fiber. The core serves to separate the outer layers. The farther they are from the central (neutral) plane, the stiffer the board. So, the core could easily be foam if it didn't break down. Maybe that's why foam was abandoned - it broke down under flexing.

The core should withstand flexing to extreme deflections without breaking. It just needs to keep the top & bottom laminations separated.

I wonder how balsa would hold up (probably not very well)?

balsa, is used in touring skis as well as cross country skis.

Burton played with it and if you use it grain direction becomes really important. as far as I know you can only use it if the grain is vertical AND you only use it in select areas of the board or ski

Link to comment
Share on other sites

Maple is extremely heavy and better restricted to the insert areas. Aspen is used by most companies due to its weight and flex memory. It rebounds extremely quickly back to its original (pressed) shape which translates to a snappy flex and quicker edge to edge turns. A little know advantage of Aspen is that it is really easy to machine and work with, so that's another reason why it is the wood of choice by the majority of manufacturers out there.

As for other wood species, poplar is also popular (no pun intended), but mostly due to its cost. Balsa is too weak and absorbs more resin than Aspen, so the weight savings are actually quite minimal. Bamboo has its place as a stringer, and so do some lighters woods like Suma (an African wood).

Anyway, I could talk about this stuff all day...

Link to comment
Share on other sites

The driving force behind the use of Aspen in snowboards is really the freestyle market. It's very light and usually less expensive than Poplar. It does OK in most situations and is something I use in moderation in some of our models. I use a great deal of poplar primarily because it has an appropriate strength and is readily available with clear, straight grain. I also use Ash and Maple for certain applications and laminates in the boards. Different lumber species can produce very different characterisitcs in the board, even if the board has the exact same flex pattern.

As the core of the board realy only sustains a shear load, flexural strength isn't really important. This is a primary reason that cores a vertically laminated instead of horizontally laminated (like plywood). Hot used to produce a hybrid core that incorporated a horizontally laminated core with vertically laminated sidesticks. They are the only company I know of that ever did anything like this, unless you look at the Yama monoskis.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share



  • Recently Browsing

    • No registered users viewing this page.
×
×
  • Create New...