Core made of single piece of wood

For discussions related to ski/snowboard construction/design methods and techniques.

Moderators: Head Monkey, kelvin, bigKam, skidesmond, chrismp

Post Reply
uni412
Posts: 30
Joined: Mon Sep 04, 2006 1:40 pm

Core made of single piece of wood

Post by uni412 »

Hi,
I was thinking about using only pine in the cores of my next skis since I want to see how changing core thickness but not it's wood type effects the ski's stiffness. Since I would only be using one type of wood, would laminating the core really be neccesary? Would I notice a major difference in the ski's flex/liveliness/pop?

Thanks,
Cameron
heybulldog
Posts: 17
Joined: Wed Jan 02, 2008 3:41 am
Location: Reading, Pa

Post by heybulldog »

You could use one piece of lumber but you would need to use a plank that was quarter sawn (vertical grain)from the log. If you flex a piece of wood across the tangical of the flatsawn grain it will break along the grain lines. This is realy prevalent with pine because it has such a diffrence from the spring growth and the summer growth. It would be better to rip it into strips turn them 90 degrees and glue back together so the grain is vertical not horizontal.
You will have a realy hard time finding quartersawn pine in a lumber yard. You will have to find a furniture lumber dealer like Woodcraft of Woodworkers Warehouse to get it.
If at first you don't succeed, try try again.
G-man
Posts: 600
Joined: Sat Mar 25, 2006 3:58 pm
Location: northern sierra nevada

Post by G-man »

Hi uni412,

As you may have noted in some of my past posts, I use pine pretty much exclusively in my cores. Usually, I cut the preliminary strips 1 1/4" x 1 1/4", then orient the strips with the grain running vertically, and then rip them in half on the band saw. Then, I glue the strips together vertically so that I get a 1 1/4" thick (by 6 inch wide) core blank that I then rip in half again to yield two vertical grain bookmark 9/16+" thick core blanks. Is all this really necessary? Not really, in my opinion. Why do it then? Mostly because I like the look if the laminated core. If I was using a top sheet that blocked out the core, I really don't think that I'd do a laminated core... until, of coarse, I got a ski that went all goofy on me after it came out of the press.

I've done a lot of home-brew stress testing using pine strips. I cut the strips about 1/8" thick and about 4 feet long, with the grain running in every imaginable direction. Then, I grasp a strip at both ends and bend the strip into a circular shape until it breaks. It's pretty amazing how strong the pine strips are. Usually, I can bend the strips until they touch end to end before they break. I've really never been able to ascertain that any particular grain orientation was any stronger or weaker than another. I admit that the quality of pine lumber that I use might better than what most folks might easily find because I mill my own and get to choose from an inventory of about 100,000 board feet. But, as long as you don't get hold of a really squirrely piece of wood, I think that a non-laminated core would work just fine, especially if you're mostly experimenting with core thickness and it's effect on overall ski stiffness.

One of the early 'mantras' of this site was "go ahead and try anything and everything and see how it works"... and report back, of course:).

G-man
TexMurphy
Posts: 42
Joined: Fri Sep 14, 2007 8:59 am

Post by TexMurphy »

Im gonna be using pine for my 2nd pair of skis. Im using birch for the first pair and I want to compare the two tree typs and how it feels to ski them. So I will be doing same shape and thickness.

Though what I want to do in the longrun is to use pine. Two reasons really first there is lot of localy grown pine and second its cheap (due to first).

Hopefully Ill get good enough result from the pine and can just add stripes of stiffer to controll the flex between cores.

But really using localy grown is very appealing to me.

Tex
uni412
Posts: 30
Joined: Mon Sep 04, 2006 1:40 pm

Post by uni412 »

Thanks for all the responses. I think I'm going to try to use a single piece of wood for the cores and see what happens. I'll be sure to report back. I feel that if the main purpose of the core is just to give space between the fiberglass layers, maybe the grain direction/strength won't have that much effect on the ski.
User avatar
littleKam
Site Admin
Posts: 269
Joined: Mon Dec 13, 2004 7:43 pm
Location: SoCal

Post by littleKam »

i've also been using single planks of pine in my skis as well. I haven't been able to fully test the skis because of some issues concerning geometry and stiffness. But I have made a hopefully "regular" ski out of pine and will test with an alpine setup this weekend. I'll let you know how it goes.
- Kam S Leang (aka Little Kam)
uni412
Posts: 30
Joined: Mon Sep 04, 2006 1:40 pm

Post by uni412 »

Thanks alot, I look forward to hearing how they work.
uni412
Posts: 30
Joined: Mon Sep 04, 2006 1:40 pm

Post by uni412 »

littleKam, did you ever get a chance to try out those skis?
Greg
Posts: 225
Joined: Thu May 26, 2005 11:41 am
Location: Sweden but home is NW Washington

Post by Greg »

I too have made a couple pairs of skis from single pieces of pine. I haven't actually gotten a chance to ski them yet though, but they feel fine when they are flexed, and they have held their camber well.

Plus, by using a single board, you can purchase a 12 foot long 1x6 and you get enough wood for 2 skis. Plus, if you go to a good lumber yard, you can dig around and find one nice board. The price is sure right when you compare pine to anything else as well.
Post Reply