Twizz 2012/2013

twizzstyle · Post by **twizzstyle** » Sun Nov 04, 2012 3:00 pm

I just love the idea of a ski that can "breath". Regardless of the functionality of it, seems like a good gimmick someone could use to sell a pair of skis

Last night I cutout the foam cores (that I'm doing instead of honeycomb for now), and epoxied the sidewalls on. Tomorrow I'll profile them. Me and KevyWevy have a ski building day planned for next weekend with four pairs ready for pressing... we'll see how many skis we actually get pressed...

twizzstyle · Post by **twizzstyle** » Mon Nov 05, 2012 6:23 pm

I profiled the foam cores today. This is the 4th pair of skis I've now profiled - with sidewalls - on the CNC machine with no sidewall damage!!!! What a change from the challenges of the past.

The foam cores (with sidewalls and inserts) weigh exactly 540g each. CNC consistency rules!

The bamboo cores (with sidewalls and inserts) weigh 825g. 285g difference per ski isn't huge, but it's not bad!

The foam core obviously isn't as stiff as the bamboo so I had to account for that. The foam core does have some ribs of fiberglass so it has a little stiffness, but not much. I setup a little test fixture with two identically sized/shaped pieces of foam and bamboo. I mounted them as cantilevered beams and hung a known weight off the end, and measured the deflection with some calipers. From that I calculated the modulus of elasticity - whether or not the final number was entirely accurate, I don't really care, what matters is I was consistent so for comparison purposes it should be spot on. From that I could calculate what thickness of foam core would give me the same stiffness as the bamboo core, all else the same. In theory. The end result was that with the bamboo core at 10mm in the middle, the foam core needed to be 12mm in the middle. I'll see how well that theory actually works out after layup

falls · Post by **falls** » Mon Nov 05, 2012 7:02 pm

1 pound on the foot is like 5 pounds on your back (or something like that!)

twizzstyle · Post by **twizzstyle** » Sat Nov 17, 2012 5:37 pm

A little sneak peak of what we've been working on. These are Kevin's (KevyWevy) new powder skis.

More photos and information later.

I've still got everything ready to go for my two pairs of new powder skis, including the foam core ones. Hoping to layup both those pairs this week.

twizzstyle · Post by **twizzstyle** » Sun Nov 18, 2012 5:41 pm

There is a good string of storms coming to the PNW this week, and I got word earlier today that one of the local mountains (Baker) may be able to open on Wednesday.

Now I'm in turbo mode trying to make these skis as quickly as possible to have them for opening day. Rushing ski building is never a good thing, but snow's coming so I've got to hurry!

The first ski of my new pair is in the press now. It was a bit hectic rushing to get everything ready for layup this afternoon. Drag-knived the bases, came out perfect, glued the edges on, and I must say it was the best edge fit I've ever had. Looked pro. Then I pre-bent the tips, and the edges popped right off in the tips - awesome. I was using a new super-glue I got, turns out it takes FOREVER to cure, unlike the last stuff I was using. So that sucked, fingers crossed the edges stayed put after I re-glued them. Another 30 minutes before I pull it out.

ben_mtl · Post by **ben_mtl** » Sun Nov 18, 2012 6:34 pm

As far as edges glue goes I used to do with "Loctite Super Glue" (red bottle).
I love it but it's very expensive if you consider the small amount of glue in every bottle. Lately I got a hand on some other cyano glue and it's freaking powerful and dries fast.
With the loctite glue if I saw my edge fit was not perfect I just had to wedge the tip of a screwdriver between the edge and the base to break the bond and do it again locally... with the new glue there's no way I can do that, on my test piece I checked to pop the edge off the base and couldn't do it, it just pulled pieces of the edge material with the edge !... I guess I'll stick with Loctite until I'm better ared edge fitting...

Twizz -> I love those topsheets !

twizzstyle · Post by **twizzstyle** » Sun Nov 18, 2012 6:45 pm

So what I've used in the past was Loctite super glue gel, it comes in an easy-squeeze blue/gray bottle. Works good, and dries fast, but like you said its expensive and you get hardly any glue. One bottle is good for maybe two pairs of skis, if that.

I bought some general hobby CA to use instead, and that's the stuff that takes way too long to dry. Sounds like I need the super strong stuff you've got!

Just pulled the ski from the press. Looks like a ski! Base seems pretty flat, camber looks how I wanted (heated from the top to reduce camber from the mold).

Only one boo-boo, which is a weird one I've never had, and hard to explain. Near the tip, in the early-rise section, on one side of the ski, the whole ski was "bent" the wrong direction. My only guess is something must have gotten under the cassette when I was rushing everything into the press. Maybe a chunk of epoxy from the last ski? When I put a straight edge on the base running longitudinally, it made a bridge about 4" long with about 1/8" gap between the base and the straight edge - not good! Again, it was only on one side of the ski. I know the mold is perfectly flat, as is the cassette. Pressed at 60psi and all the layers are squished tight, so it's not like there wasn't pressure in this area. Must have been something under the cassette, that's the only explanation that makes sense.

I laid the ski on top of a big round piece of metal (it's actually my tip bender) upside down, with some clamps on either side trying to push this into the shape it's supposed to be in, and then got it nice and hot with my heat gun. I think that might actually have been enough to soften the epoxy and fix it, but I'll leave it in the clamps until tomorrow. It's in the early rise so it won't effect how the ski functions, it's just kinda ugly if you notice it

I'm tempted to lay up the other ski tonight, but I'm out of the Loctite, and don't want to tempt fate with that other super glue. I've still got two more days before we hopefully hit the slopes (and it's not like I don't have a huge pile of other skis ready to go at a moment's notice

)

amidnightproject · Post by **amidnightproject** » Mon Nov 19, 2012 5:32 am

twizz, pickup some of this stuff

http://www.scrollsawer.com/reviews/flex ... -glue.html

Takes about a minute to set. If that. And if you really need to remove the edge from the base, it'll rip off with a bit of muscle and some leverage.

Other then it being about $5 a bottle it works well.

knightsofnii · Post by **knightsofnii** » Mon Nov 19, 2012 8:46 am

re-press the ski if you have to,
take the temps up to like 200

some epoxy's although irreversible... can get reformable (a little!) with some heat and pressure.

twizzstyle · Post by **twizzstyle** » Mon Nov 19, 2012 10:42 am

Nice, thanks Doug. I'll give that a shot tonight if my clamping jig didn't do the trick. At work now so I'll find out this afternoon.

vinman · Post by **vinman** » Mon Nov 19, 2012 3:57 pm

Plain old super glue from big lots. I don't like the gorilla brand stuff. I make less mess with the thin stuff.

Brazen · Post by **Brazen** » Mon Nov 19, 2012 4:35 pm

This stuff is pretty good, and with the accelerator as soon as you're done edging you can pull the clamps. Fast. Cheap. Never lost an edge in the press. http://www.glue-shop.com/info2.htm

twizzstyle · Post by **twizzstyle** » Mon Nov 19, 2012 6:25 pm

That's basically what I was using, but without accelerator. Any concerns with the accelerator in the layup? I have these thoughts in my head about the accelerator causing issues with the epoxy, or delam, or something bad.

Just trimmed up the ski, ground the edges and cut the sidewalls. Dang, it looks good. The clamping/heating fixed the bent base issue about 90%, it's still a little funny, but you really can't see it now. Edge fit is great, no delam anywhere, really proud of this one, base is pretty flat too, I only did a few light passes on the base and it was already grinding pretty much the entire width of the ski (not normal for my skis). They're stiffer than I wanted, but this gives me a good new baseline for profiling with the CNC.

I must say I think this is as wide as I need to go, ever. They're ~155 at the tip, which is the same as my last powder skis, but these are that wide for a looong time, they look ridiculous! I'll get photos up when the second ski is finished.

rsotak · Post by **rsotak** » Tue Nov 20, 2012 11:40 am

The accelerator shouldn't have an effect on the epoxy cure chemistry. The great thing with accelerator is you can apply it to the surface and let it dry. When you apply the cyano later it kicks off really quick.

I used this on my last set of skis and it seemed to work really well.

knightsofnii · Post by **knightsofnii** » Tue Nov 20, 2012 12:57 pm

we now use this stuff called 2P-10

Its basically slow curing super glue with a spray bottle activator

put the glue where you want it, dab it up if it's bubbled up too high, spray the activator, kicks instantly, before you have time to remove the clamps its done, of course we wait like a minute.

It's not perfect, but it's as good as normal super glue and way faster.

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Twizz 2012/2013