Anyone out there have any experience using nomex honeycomb? I was thinking it would make an interesting core material. I see Burton's new Vapor board is using a honeycomb core which supposedly saves a full pound. I'd sure love to take a pound off my backcountry boards...
paul
I got a 20x20cm piece of honeycomb and I laminated both sides with carbon. First I impregnated the two carbon sheets, then I glued them to the nomex with epoxy.
The only problem if you want to make skis is the tapering. Nomex is not the easiest thing to cut. Then you should put some reinforcement in the binding area, so the screw will not be pulled out.
Im pretty sure the kids who build skis out of the U of U tried some honeycomb...
How about using a tapered wood piece above a flat honeycomb piece for a sortof composite core?
something like this:
that wouldn't be too tough, i'd think, easier than tapering honeycomb. probably back to wood for the tip and tail if the honeycomb couldn't handle a bend there also.
my dream ski:
105 mm underfoot, moderate sidecut, moderately stiff...
but only 4 - 5 pounds per pair.
my current powder plus's weigh in at 10 pounds total. sooo heavy.
I saw those jib skis the U of U guys built. Pretty cool ideas there. I wanted to ask them about the honeycomb, but the contact info I've got isn't working (jib_ski@yahoo.com). Anyone know how to get a message to those guys?
thanks,
paul
We milled out a section of the core in both the tips and tails and replaced it with honeycomb. The honeycomb was then pre-bonded to the top of the core using a sheet of 16 ounce biaxial fiberglass. This was necessary so that the cells did not fill with resin during the wet lay process which would have inherently negated the benefit of the weight saved by using the honeycomb in the first place. After the resin cured, the honeycomb was sanded to match the core profile.
If you've got any more questions just post them on the forum here. I'm working up in AK now and cannot access yahoo mail from my work computer.
cheers
Right, don't want the cells full of resin. Did you mill the core all the way through? Just partway? And would you say honeycomb has strength/stiffness properties that make it a good core material for skis?
Thanks for the info, this is helping.
paul
First we cut the honecomb into thin sheets using a bansaw, just barely thicker than the thickest pat of the core where we were implementing it. Next we milled the core all the way through (actually I think we were getting too much vibration when milling so we went with the bansaw and chisel method) and fitted the honecomb in the milled out slot. Unfortunately this relieves all the internal stresses, and the free ends of the core want to branch outward when you do this so we had to epoxy the outside walls of the honeycomb to the insides of the milled out section of core, put it in compression using tape, rubberbands, or a vice, and let it set before pressing. You'll want to do this on all 3 sides of the honecomb that contact the core, we had some delam issues at the transverse wood/honeycomb convergence point. We then took it to the belt sander to profile the honecomb to the exact shape of the wood.
I'd say the diameter of each honeycomb cell was less than 1/8", and if you held a ski core machined out of this in the middle there would be noticeable deflection at tip and tail due to its own weight. We used ploycarbonate honeycomb, aluminum honeycomb may be more suitable here. The weight of the fiberglass implemented above and below the core definitely contribute substantially to the flex of the finished product. On our skis there was a noticeable difference from the 17.5 to 20 oz glass.
If you were to use honeycomb for the entire core you'd end up with and extremely light ski but I think the flex would suffer some. Wood just feels more solid underfoot for me...
hope this helps
Rory
to broskier: can't you add pop(stiffness) maybe using carbon stringers or a full carbon sheet on top or bottom???
carbon definitely helps add some pop, we used several stringer in the tails of both of our skis
be careful how much you use, a little bit goes a long way
also, carbon has a negative coefficient of thermal expansion so it reacts differently than all your other layers to the changing temps, both during pressing and up in the snow, we didn't experinence any delams due to this but if you used a full sheet this might be more of a problem
