Ski Builders Forum

for a park ski, what is more likely to delam with all else equal full wrap or 3/4?

i think a full wrap will delam easier but i haven't made a park ski and I dont ride park.
I would mKe one of each and do the standing slap test on concrete and see what happens.
Stand on the tail and flex into the ski with your other foot and slap it down.
I bet the metal tip will delam faster because its not as flexible.
I also think laminate pressure has allot to do wit this. If you press at 100psi vs 50psi, the laminate will hold together better if you do it right and remember rubber always increases bonding.
this should be posted as a poll.

If you assume you can get the same probability of delam with each method (the exact opposite of your question...), you might consider this: A park ski can be considered more expendable than a non-park ski... I.e. it will inevitably get trashed. Full wrap is a lot more work to get it nice than a 3/4 wrap, and is that extra effort worth it for a ski that will get trashed?

(for what it's worth I do full wrap on all my skis, park or not, just cause I think it looks nice)

we the goal is to make the best ski possible, i agree that they are just going to get trashed, but if full wrap lasts longer the extra effort is worth it. what do you do with the end of the edge if you do 3/4 wrap. just end it or do you tuck it in somewhere. i was thinking about safety wiring them together to keep them from blowing out. bad idea?

There have been a few people on here that have strung kevlar across the width of the ski/board using the edge tines just as extra insurance. Pretty clever if you ask me, and kevlar would be a much better choice than safety wire. The edge should just end, it doesn't get tucked in anywhere, just cut it.

to do 3/4 edge wrap most people tape/glue a piece of tip spacer around the tip and tail on the template they route the base material with. the tip spacer is about 2mm thick so when you route the base you end up with a 2mm wide offset around the tip and tail. It leaves a circular notch that you need to square up with a scalpel/box knife and then you cut the edges to length so they sit in correctly.

Capped template with tip spacer material

Close up

Edge recessed behind offset in base material created

How do you get the edges to go flush like the one in your picture or when I see them on skis when they are not fully wrapped? Is the bottom template cut so the edge will lay into the side and then end near the tip or tail?

thanks

Read my post above the pictures, then look at the pictures...

i think i am going to try the 3/4 wrap. i like the way that your edge is flush with the base. just wondering how u get the square cut in the base, is that what u use the exacto knife to cut. i dont use tip spacer, but i am very interested about using the kevlar sounds like a great idea, can u elaborate on how you use it.

thanks

You want to look at Carlito's work: viewtopic.php?t=2922&highlight=carlito

This is a good video : http://www.swellpanik.com/uk/

ggardner90 wrote:i think i am going to try the 3/4 wrap. i like the way that your edge is flush with the base. just wondering how u get the square cut in the base, is that what u use the exacto knife to cut. i dont use tip spacer, but i am very interested about using the kevlar sounds like a great idea, can u elaborate on how you use it.

thanks

I don't use it, I've just seen others using it. It's one of those things that you shouldn't use to prevent an underlying issue in your ski (delam/edges ripping out). Those are issues you should be able to solve on their own, but there is no harm in having extra insurance built-in to the ski such that if you do bork up the layup, your chances of issues is smaller.

You want to get kevlar tow, just threads of kevlar basically. Tie it to one of the edge tines, and then thread it side-to-side, looping it around the edge tines with a little bit of tension in it. I wish I could remember who was doing that, they had some good pictures of it (it was a snowboard if I recall)

falls wrote:to do 3/4 edge wrap most people tape/glue a piece of tip spacer around the tip and tail on the template they route the base material with. the tip spacer is about 2mm thick so when you route the base you end up with a 2mm wide offset around the tip and tail. It leaves a circular notch that you need to square up with a scalpel/box knife and then you cut the edges to length so they sit in correctly.

Tip spacer works perfectly to offset your base.
I've contact cemented it and stapled it to different templates.
The last time I used the brad nailer, quick and easy and pulls right out if you decide to do full wrap next time.

Richuks link above shows how carlito used kevlar tow, gotta scroll down a bit.


sam

yeah the exacto knife is used to "square" the plastic where the end of the edge fits in.
As a router bit is circular it can't create a 90 degree corner, so when you follow the template and it rides off the MDF and out onto the plastic material (or use any material that is the same width as your edges) it leaves a quarter circle shaped notch. I use the exacto knife to cut in towards the template and then flush along the template to leave this notch at 90 degrees so the edge sits in flush. I attach the edges with a few spring clamps then cut the edge to length with a dremel cutting disc then use the drum sanding piece on the dremel to shorten the edge until it fits snuggly in place.

Way less effort than full edge wrap.

twizzstyle wrote:You want to get kevlar tow, just threads of kevlar basically. Tie it to one of the edge tines, and then thread it side-to-side, looping it around the edge tines with a little bit of tension in it. I wish I could remember who was doing that, they had some good pictures of it (it was a snowboard if I recall)

IIRC, there was a 333skis video that had this. Don't know if the video still exists on the youtubes. Just sayin...

falls wrote:I attach the edges with a few spring clamps then cut the edge to length with a dremel cutting disc then use the drum sanding piece on the dremel to shorten the edge until it fits snuggly in place.

Last time, instead of this, I tried trimming the slot in the base to fit the edge instead. It worked out okay. Sanding/grinding down the edge bit by bit is probably a more precise way to do it.