binding mount reinforcement

sammer · Post by **sammer** » Wed Oct 14, 2009 9:23 pm

Just wondering what, if anything, everybody else is using?

I've tried aluminum window screen on 4 of the last 5 pair.
The last got a thin (.025") aluminum plate.

Window screen doesn't do as much as I thought.
I've still had issues with screws coming loose and stripping out.

I've been thinking of just using triax as I always seem to have left over pieces laying around.

Just curious what your experiences are.

thanks

sam

Dr. Delam · Post by **Dr. Delam** » Wed Oct 14, 2009 10:05 pm

How are you going about mounting the skis? Is a shop doing it or are you? There shouldn't be a need for binding reinforcement if it is done properly.

rockaukum · Post by **rockaukum** » Thu Oct 15, 2009 6:10 am

Lets hear your suggestions on the right way. I currently use inserts but have a need to do wihtout them.
ra

Nick's Sticks · Post by **Nick's Sticks** » Thu Oct 15, 2009 7:53 am

I am playing with cedar cores. I expect the screws will pull out If I don't reinforce them. In the past I used and extra layer of biax glass with a copped strand mat under the binding area. Since I don't think this will fly with cedar I routed out a 2.5mm deep trench in my cores and added a layer of poplar above the core. My plan is to put light weight glass between the two layers of wood to improve the bond.

SHIF · Post by **SHIF** » Thu Oct 15, 2009 9:51 am

On one pair I added an extra layer of triaxial glass under foot. On several others I added nothing. These all had one layer of 20oz. triaxial glass and one layer of 4.5oz unidirectional carbon fiber above and below their bamboo cores.

Be sure to use the proper size drill bit for your binding screws. In my case that is 3.6mm (9/64"). Also use a waterproof wood glue in the holes when mounting the bindings, I use Titebond type 3. So far we've never had a problem with bindings staying attached to the skis, and they have been put through some high-stress situations on the mountain.

Cheers,
-S

MontuckyMadman · Post by **MontuckyMadman** » Thu Oct 15, 2009 11:17 am

Did you use one piece of screen? It should be doubled up. Chopped fg matt is what many manufacturers are using. Moment, ON3p, Iggy can correct me.

I flail hard and wipe out when I huck and ride tele. My poplar skis were some of the hardest to drill and screw into that I have ever done. Mounted about 30 different pairs of skis alpine and tele.

Perhaps wood type and or mounting technique and hardware could be a combo of factors.

I use the AL door screen doubled over and you can feel it when you drill and screw through it.
Maybe its a compressions thing pneumatic press or vacuum?

sammer · Post by **sammer** » Thu Oct 15, 2009 8:15 pm

Thanks for the replies.

montucky... I've just been using a single layer of AL screen and I'm vacuuming.

shif... I've been using proper drill bit, hardware, and jigs.
My buddy is a ski tech so I have access to all the gear for very little beer

My cores are generally made with SPF with maple stringers and sidewalls.
The maple doesn't always line up with the binding screws although it would be cool if it did.
I haven't had a binding pull out. Just screws stripping when retightening (as they do seem to come loose)
I don't think I'm over torquing them, just the pine or spruce is just too soft to get a good hold.

Keep them coming though.

sam

twizzstyle · Post by **twizzstyle** » Thu Oct 15, 2009 8:57 pm

Are you putting in wood glue before you put the screws in? I've never had a screw work its way loose on me...? I've been doing just an extra layer of triax in the binding area, although I don't think I really need it. I figure it won't change the stiffness of the ski much in that thick area, and it doesn't add much weight so why not have the extra insurance. But pullout doesn't sound like your problem, if the screws are becoming loose. Maybe try more glue? It should be pretty damn hard to take a screw out of a ski.

sammer · Post by **sammer** » Thu Oct 15, 2009 9:08 pm

Yup, wood glue in the holes. Not sure why this is happening as i believe I'm doing all the right things.
So far its only happened on one pair but that's the pair that get the most use ( probably 45 days and 10 different users)
(perhaps one of them got carried away with the screw driver trying to do me a favor?)
The local ski patrol had them for 2 weeks of "stress testing"

I'll probably just use an extra layer of triax for most but the ones that will get abused will probably get the aluminum plate.

thanks

sam

MontuckyMadman · Post by **MontuckyMadman** » Thu Oct 15, 2009 10:43 pm

I think its the spruce, pine, fir. Try poplar or beach or maple or ash or cherry even bamboo or aspen .
Moment had trouble with spinners like that and then they added that chopped glass sheet in the binding area. They use pine in their core.

Idris · Post by **Idris** » Fri Oct 16, 2009 12:42 am

Easy problem to solve. Stop using wood glue - it only acts as a lubricant to get the screw in, then does virtually nothing. Take some screws out of an older pair of skis - you will find rust.

Solution use epoxy - even the supermarket quick set stuff does a reasonable job - proper epoxy is better. To get any troublesome screws out again put the tip of a soldering iron on the screw for a few seconds to brake the bond if it's good epoxy it may take a few more seconds.

Since I've been mounting bindings with epoxy I've suffered no pullouts. When I haven't had any epoxy to hand and have been in too much of a rush to get any I've resorted to gorilla glue or it's equivalent - this is messy but hasn't failed yet - doesn't keep the water out quite as well as epoxy though

rockaukum · Post by **rockaukum** » Fri Oct 16, 2009 6:15 am

I don't recall where I heard this but "binding glue" is melamine glue. Perhaps give it a try also.
ra

telethor · Post by **telethor** » Mon Oct 26, 2009 6:52 am

Second Idris' suggestion. Have yet to finish building my own skis, but when they're done, they'll be getting epoxy in the holes. Never had any pullouts or loose screws in my other skis with epoxy instead of wood glue. And the soldering iron trick for removal works like a charm. I've used the 5 minute stuff and the several hour stuff. Lately, I've been liking the quick setting JB Weld epoxy. Works quite nice. Previously I had several wood glue mounts where I removed the bindings and saw rust from the wood glue. No good IMO.

sammer · Post by **sammer** » Mon Oct 26, 2009 5:38 pm

Thanks everybody, I will definitely try epoxy instead of wood glue.
Will also try an extra layer of triax.
Don't want to give up my SPF cores as I have a lift of rough 1x4's (fir and larch) under a tarp in my back yard

And pine 2x4's are dirt cheap
Wish I had a lift of maple or poplar!

sam

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binding mount reinforcement

binding mount reinforcement