[24Dave]

DTrain,
Hey I saw your skis with the yew sidewalls on facebook. I'm trying to increase the compressive strength of some paulownia cores without stiffening them up too much. Does the yew wood seem more flexible than say hard maple?

Do you have a referral for finding some pacific yew?

[Dtrain]

Exact same weight as hard maple. 20 percent softer on flex. Hard to find for sale. And clear wood almost impossible. I pulled em out of the bush myself. If your in Washington/Oregon you can find them

[24Dave]

Ha, That's kinda what I have been learning. Thanks for the quick response. Reckon I'll just use the maple I have and adjust flex and weight elsewhere in the recipe.

It looks like the bow makers gobble up any clear yew at pretty good prices if you find some good logs.

[Dtrain]

hope everybody is well.......I'm starting to get itch cause the temps are dropping, though I haven't really been in the shop that much or at all over summer

sketched up a new shape for my oldest son Noah. He outgrew his last one


106cm
clear polymide topsheet
maple leaf
9oz uniglass
sitka spruce core w/ no sidewalls
18oz 0/90 biax glass
edge
black crown extruded

kids beginner pow stick
20mm setback stance
9mm of tail taper
A little camber

Entropy with a shot of blue dye (came out blotchy).......not enough dye probably, only used one drop.


The asym composites layup and top/bottom heating diff really allowed me to pull this thing convex along with the uni providing more torsional flex for his riding ability and weight.

Weird thing is though.....the running length was affected more than the tips. I figured it would be the other way around as there is less wood thickness for glass to offset it the tips?

Either way the catch should be eased up, and the things gonna rip pow!

Base shot is taken with bindings mounted (which flattened it out some)


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[SleepingAwake]

[Dtrain]

That sounds like it could be reason for sure, Appreciate the the feedback Reto.

Thanks,
Derek

[skidesmond]

He looks pretty happy with them!

[FigmentOriginal]

Kid looks super stoked, so great! Can't wait to see what comes out of your shop this year. Your shapes and splits are top notch!
_________________

[24Dave]

DTrain, he looks stoked, kids are awesome.

I am wondering one thing though. I would have thought that since you only had glass going across the board on the base in the 90 degree orientation, that the base glass would have expanded with heat, then contracted after heating and curing and would pull the base into convex.

Do I have this backwards?

I'm curious to know as I am making my kids splitboards this year and will be using glass and I really have only used carbon and carbon-aramid blends and have not had problems getting flat bases, so no experience really.

[Dtrain]

You have it right Dave. As for this board the glass expands on bottom only because there is no 90 on top. When it shrinks it can’t pull flat because it must pull the core too. This is the reason as mentioned above there is less effect in the tips because the core is thinner along with less heat diff. top and bottom in those areas.

[24Dave]

Thanks for your reply Dtrain and enjoy that snow up there!. Essentially dry down here, but enough to facet. I wrote my last message wrong.

So the take away is that the single side (the base) that has the 90 degree or cross board glass will end up expanded and make the base convex.

Could this be a resin expanding and not shrinking effect since your base was heated more than the deck and the effect was less where the core was thin?

My original thought was that the glass fiber expanded with heat and then contracted which in your case would have made the base concave ( I mistakenly wrote convex in last post).

I think I am inclined to just use 90 degree carbon and uni glass lengthwise. I really don't want to end up with a concave base.

[Dtrain]

Whatever you choose remember i only did this to create more torsinal flex for the little guy. The convex base is just a bonus on his board. If I wanted to spend more time on the board I could of just thinned the core out between the binding inserts to get the torsional flex. I would never want to thin the core out on a split where it will flex the most during touring. That said Splitboards flex way more torsionally as they are two pieces.....food for thought if anything! I don’t really have any idea what I’m doing. I used to think I wanted to sell boards and skis due to interest from others. That was just a big pain in my ass that killed the love for being in the shop. Now I’m happy just screwing things up for friends and family again! And ya it’s been dumping here up high. Getting out for a hike on the weekend. 🤘�.

[24Dave]

Thanks, Yeah I have been getting mixed messages on the forum about whether its expansion or contraction of glass that makes glassed boards go out of flat sometimes. Time for me to just have a go.

I hear ya on fun in the shop versus building a side business. I think I have loved the tax benefits the most from having incorporated. If I even had to make 5 of the same board, I would be bored and it would be a drudge.

[Dtrain]

I read a long paper that tested composite expansion and contraction. the average fiberglass (unknown weave and weight) sample expanded .92 percent mixed with epoxy in a 75 degree celsius cure. It does expand when heated for sure. It is as what rate/how even and the same for the return to room temp and what core material, if any, it is encapsulating that create a wide array of variables!