I've been thinking about a combo vertical / 2 layer horizontal laminate idea where the bottom layer would be a standard easily built, lighlty tapered layer with the top layer being a more structured piece shaped for stiffnes both torsional and flexural. I'm a bit worried about the horizontal layers delaminating.
Any input?
horizontal laminate for flex control
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doughboyshredder
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Bucky Mullet
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if i get you right you`re thinking about using a vertical woodcore with veneer on top of it?
this is what i do. vertical woodcore sandwichted between two veneers. i just profiled the vertical part of the core and then glue the veneer on top and bottom. you won`t get any problems if you press carefully. there can be some differences depending on thich type of veneer you`re using. of course you have to flip one layer because of the grains.
for example ash has very distinctive grain structures. there is some harder wood in the veneer, from the yearrings of the tree. this creates some small bumps and irregularities. on the other hand maple has similar properties as ash, but has far less "hard grains" - maple veneer is really even and plane and maybe more suitable for such a purpose.
furthermore, if i did get you right, you want to change flex with the veneer layer, richt? to be honest: forget this. i don`t think the type of veneer will have any impact on flex. the thickness of the veneer will have, but it is just able to make a ski stiffer or softer because the change in thickness runs over the whole ski. if you want significant change in flex patterns you have to change the profile of the core and the ratio of thickness in center/tip and tail...
this is what i do. vertical woodcore sandwichted between two veneers. i just profiled the vertical part of the core and then glue the veneer on top and bottom. you won`t get any problems if you press carefully. there can be some differences depending on thich type of veneer you`re using. of course you have to flip one layer because of the grains.
for example ash has very distinctive grain structures. there is some harder wood in the veneer, from the yearrings of the tree. this creates some small bumps and irregularities. on the other hand maple has similar properties as ash, but has far less "hard grains" - maple veneer is really even and plane and maybe more suitable for such a purpose.
furthermore, if i did get you right, you want to change flex with the veneer layer, richt? to be honest: forget this. i don`t think the type of veneer will have any impact on flex. the thickness of the veneer will have, but it is just able to make a ski stiffer or softer because the change in thickness runs over the whole ski. if you want significant change in flex patterns you have to change the profile of the core and the ratio of thickness in center/tip and tail...
plywood freeride industries - go ply, ride wood!
Shaping cores can be a pain. I've often thought of making a bunch of 3mm flat cores and then using another wood core on top in order to customize the flex. In my actual experience I've concluded that it is simpler to make a one piece, tapered core and then alter flex patterns with carbon stringers and additional layers of fiberglass. I've found that minor alterations in core profile lead to big changes in flex but when I change the fiberglass and carbon layup I get smaller and more manageable alterations in flex.
That said, I'm not sure why you couldn't just use vertical lamination (or horizontal) for both pieces. You could use wood glue to put together your core pieces on your camber mold, this might be a good way to avoid camber loss in your finished skis. It might also be easier to use horizontal lamination to achieve the thinner bottom segment of your core. If you laminated these veneers on a camber mold you could get even better camber retention. I would avoid trying to lay up the core at the same time as you're laying up the skis. There just seem to be too many things that could slide around in your press.
I use veneer top sheets and have had no problems with delamination. Veneers tend to soak up glue and epoxy and this seems to hold them together quite well.
That said, I'm not sure why you couldn't just use vertical lamination (or horizontal) for both pieces. You could use wood glue to put together your core pieces on your camber mold, this might be a good way to avoid camber loss in your finished skis. It might also be easier to use horizontal lamination to achieve the thinner bottom segment of your core. If you laminated these veneers on a camber mold you could get even better camber retention. I would avoid trying to lay up the core at the same time as you're laying up the skis. There just seem to be too many things that could slide around in your press.
I use veneer top sheets and have had no problems with delamination. Veneers tend to soak up glue and epoxy and this seems to hold them together quite well.