Do I have to leave room for the metal edges in the sidewall?

shopvac · Post by **shopvac** » Sat Dec 03, 2011 4:17 pm

I think Chrismp is correct ... there are many ways to build a ski that works for you. We do not use heat and we do have a fabric press that is about 8" wide (so one ski at a time). We press between 40 and 50psi. One thing to note is we use wood sidewalls (ash, sometimes poplar or maple or cherry or oak) but we have never done any work with plastic sidewalls. Maybe if you use plastic sidewalls you need to cut the rabbit, I don't know and can't really comment on that.

jvangelder · Post by **jvangelder** » Sat Dec 03, 2011 5:20 pm

Well im doing snowboards, maby the extra width allows for more of an error.

pressing with heat, cat-tracked at 75psi with two bladders. sidewall is 1/2 wide including whats going to be cut off, with aprox 5/16 of that flush with the edge or inward

-Jacob

Sherpa Burns · Post by **Sherpa Burns** » Wed Dec 14, 2011 6:58 pm

For those of you using PE sidewalls and rabbiting for the edge tang, what are you doing to abrade and flame treat the recess for bonding? Seems difficult in my head to belt sand a very shallow, very narrow recess with any real precision.

Brazen · Post by **Brazen** » Wed Dec 14, 2011 8:07 pm

Just flame it.

Sherpa Burns · Post by **Sherpa Burns** » Wed Dec 14, 2011 8:16 pm

seriously? You don't need to sand or anything? You just flame it? I've been avoiding PE, just because I didn't want to take the time. Kinda wanting to get some neon style in my life with some PE sidewalls.

Also, Brazen, I wanted to talk to you about the board you built with the veneer inlays. I have stacks and stacks of remnant veneers. The combos of them would look really sweet all intertwined. Did you have it all cnc cut? Put together with some sort of backing?
Thanks,

Brazen · Post by **Brazen** » Wed Dec 14, 2011 8:32 pm

You could abrade it, I don't. I just flame it after the routing and so far, so good. I pm'd you the veneer answers

petemorgan(pmoskico) · Thu Dec 22, 2011 10:34 am

The combos of them would look really sweet all intertwined. Did you have it all cnc cut? Put together with some sort of backing?

I have stacked veneers on top of each other alot. you will get bubbles where the drop-offs are.

I then sand those down so there aren't any bubbles and the transition is smooth. I then do a finish coat ontop of everything. i have had some turn out that you cannot even feel that the veneers are stacked ontop of each other, and then others where you can feel a slight difference, but it is pretty slight. i think it depends on the thickness and hardness of the veneer.

it would be pretty awesome to do some CNC designs in veneers though.. man that would be sweet!

sir.orange · Post by **sir.orange** » Sun Dec 25, 2011 4:02 am

i just took a pair of skis out of my press where i noticed the base to concave from edge to edge. the archrise was about 1mm in some spots.

my core was ash with abs sidewalls, without any rabbet (space) for edges. i think while pressing,ash, as softest part of the core, got compressed and the abs not. opening the press, the ash expanded and dragged the base to increase that specific concave from edge to edge.
don t know if im right but this is the only possibility i could imagine so far. mould is flat.
i quit abs now for further construction, i rabbet my wood cores, hopefully to reduce any arc appearance.

OnDeck · Post by **OnDeck** » Mon Dec 26, 2011 4:15 pm

I would shoulder your edges but I doubt that caused your arc problem. Sounds like that may be asymmetry in your lAyup...different fibre orientation, use of carbon, etc?

sir.orange · Post by **sir.orange** » Mon Jan 02, 2012 7:42 am

OnDeck wrote:I would shoulder your edges but I doubt that caused your arc problem. Sounds like that may be asymmetry in your lAyup...different fibre orientation, use of carbon, etc?

i was pretty accurate in this, as i had this problem of fibre orientation before. just two layers of 22oz triax glass on both sides of the core, the UD fibres facing the wood core...

OnDeck · Post by **OnDeck** » Mon Jan 02, 2012 10:57 am

Wow, weird. The only other thing i can think of is uneven epoxy curing between the top and bottom, due ither to different heats or maybe using two different bathces of epoxy and screwing up the mix? i msut admit i'm not sure that would to arcing edge to edge.

Either way, i would still shoulder the edges!

MontuckyMadman · Post by **MontuckyMadman** » Mon Jan 02, 2012 12:39 pm

many things to cause this and it is the number one problem higher level home builders have.
1. Too hot on the bottom, uneven cure, top-bottom, or just too damn hot, try not to exceed 185 F but depends on the plastics and resins you use.
2. Edge rabbet not deep enough or just no rabbet at all.
3. Uneven pressure caused by mold unevenness or cattrack warping or lack of cattrack. My wood cattrack used to cause this.
4. Cooling the board under pressure - doesn't allow the laminate to contract evenly, I would not recommend throwing them in the snow hot but whatever works.

I personally have seen skis come out of the press concave and then 5 days later they are flat.
I have also seen flat skis go concave at cold temps on the slopes.

Many of the skis in certain shops have been ground allot to help alleviate this.
I guarantee if you fix all of the above problems the boards you make will be flat, as I struggled with this for about a year.

Richuk · Post by **Richuk** » Mon Jan 02, 2012 1:53 pm

I'm sure all of the above is correct and it is most likely a combination of factors. I don't know exactly what this means - but I have never had this issue. I think I was also lucky in my choice of GF, it's nominally quad-axial. I think it's something like 10 grams on the 90 degrees axis.

Orange, if you want to try this fibre - do some testing?

nate · Post by **nate** » Mon Jan 02, 2012 4:49 pm

I'm just finishing up a pair of skis, and I decided to skip routing out a space for the edge this time. I was left with pretty significant dimpling where the edge lies and convex base. Rather disappointed. I wonder if there might have been other factors at play as well.

Dr. Delam · Post by **Dr. Delam** » Mon Jan 02, 2012 9:17 pm

On my last pair I pulled them out hot and they looked very flat. Once they cooled on a rack they were edge high. Not too bad but noticeable with the true bar.

Before that I was letting them cool under pressure in the press and they have been consistently base high. Contradictory of what Montucky is seeing.

I always rabbet for the edge too.

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Do I have to leave room for the metal edges in the sidewall?