What's the deal with horizontal lamination?

[AlexF]

I've always wondered why horizontally laminated cores don't seem to be used.

Yes, the layers in a horizontally laminated core might seem like obvious sites for delaminations to occur. But, the strength of the joint between two pieces of wood glued together will be much stronger than the wood itself so the wood should break before the layers delaminate (providing the glue is not total crap or badly applied).

Regarding the test by clamping the wood to a bench aligned or transverse to the grain. I can see where you're coming from but a test like that won't represent what going on in the ski. Along the grain wood is stiff and strong, transverse to the grain it rubbish (just like a regular fibre reinforced composite). The test mentioned just demonstrates this. If you laminated some strips of wood horizontally and vertically and then flexed them their stiffness and strength would be the same (as long as the wood in each had the same properties, defect etc...).

I suspect the reason for not using horizontal laminations is (as already mentioned) difficulty in getting wide enough bit of wood without defects.

[sir.orange]

hi there
i was skimming throug the article but didn t figure something useful out. so here s my problem:
i found a remaining stock of birch plywood veneers here in my local wood store. 15mm, free of knots 150cm length. 6 layers lenghtwise, 5 cross.
i ll use these for the next skis.

the question i m thinking of is if i should mill the core out of the blanks, the result will be a horizontal laminated woodcore.
OR
the maybe better version, to cut stripes out of the blanks and clue them vertically?? (in this case i m thinking about to add some poplar for damping and reducing weight) to do so, might there be the problem to break the wood fibres (while flexing) which are vertical??

edit: using the horizontal blank, i m not expecting a delam on the adhesive layer, it will always be the wood that breaks first, if it s not tortured with water

[Richuk]

You might not have seen this: http://tromso.isuisse.com/aeg/aeg.htm Great stuff!

[sir.orange]

You might not have seen this: http://tromso.isuisse.com/aeg/aeg.htm Great stuff!

i know, there are some using multiplex, 333skis is also using this stuff.
i m wondering if cutting stripes and laminate them vertical has any dis/advantages?!?

[Richuk]

Wiser heads than mine will need to answer ...

[thefreshpimpofbigair]

having built a couple bows, and done extensive research on the subject I have yet to have come across a vertically laminated bow (perhaps this may be done in the riser(on a re curve), but re curve limbs are typically thicker veneer oriented vertically under glass. Self-bows: use the grain horizontally following ONE growth ring regardless of grain wayviness. This is called the back, or a self backed bow.. Bows that compromise or violate this one layer must be "backed" with another layer of veneer, FG, or for the more primitive, strands of beaten sinew, flax, hemp, etc: mixed w/ bone glue. That would be the lamination.
I could possibly understand using a "uni" ply layup.....W/ triax or xtra carbon suppling the torsional rigidity required???

[strangesnowboarding]

this is something that i am interested in, specifically for snowboards.
in following skate construction, horizontal lam provides a much stiffer platform, it still has flex and bash resistance. maybe fewer layers (3-5) would make a good sandwich.
you could also begin to play with grain orientation in each layer to get different results. i think that this kind of core would be more resilient and also hold camber/rocker for longer with the right adhesives and care in construction.