Veneer Thickness

[UJ]

We have built some skis using 0.5mm thick plastic topsheet material. I now want to do a Sapelle veneer on the next pair with a spar finish. I would like to go 1 or 1.5mm thick for a little more durability. Is this a bad idea? I searched the forum a little but did not see anything about max thickness.

The skis we built ski well and don't want want to change anything that might effect this.

[vinman]

With a veneer that thick you would definitely see on increase in stiffness of your skis. Most veneer you can buy comes in .6mm(1/32 in) thickness. Even with .6mm thick veneer you'll likely notice an increase in stiffness in comparison to a plastic top sheet. I'd consider a decrease in waist thickness of .4mm to compensate for the veneer adding stiffness.

[chrislandy]

While on the subject, if you had to lay up a number of veneers to get the size you need (the sizes I need are quite expensive as they are on the larger size of the stocked curve), do they have issues with cracking at the join after a little use due to the in use flexing?

[vinman]

I cut and joint lots of veneer. Use a little paper first aid tape (medipore) to hold the pieces together, top coat with epoxy going into the press. If the joint looks big or is gapped make sure to put a little extra epoxy in that spot to be sure it fills in. If there is a small depression after pressing, just light sand it out and finish with spar or a clear coat epoxy. I've not had any veneer joints crack or delam from just flexing a ski or in heavy use over multiple seasons.

You'll want to adhere a sheet of parchment to the upper layer of your cassette as a mold release.

[UJ]

Thanks for the advice. looks like we better go .5 or less. I suppose with the fiberglass and epoxy under this should be pretty tough.

For splicing veneers in woodworking we use a veneer tape specifically made for this. It is very thin and does not see to leave any indentation while pressing.

[skimann20]

I agree with Vin on this one. I would say that it adds at least ~20% more stiffness. I've made two pairs of veneer skis now and they are both stiffer than I wanted. i'm getting closer to nailing them but like everything with ski building, its a journey...

[vinman]

The epoxy impregnated veneer is actually pretty tough. It wears at the tips much like a plastic topsheet.

[jono]

I subtract the thickness of the veneer (plus a little more) from my core. I still tend to get skis that are too stiff (this is more due to my own neurotic tendencies during layup).

I have made skis completely from skateboard veneer and at the ends they had two 1/16 layers of maple and one layer of 1/32 douglas fir + 2 layers 19ox triax, carbon stingers and these are not too stiff. When you buy a big set of skateboard veneers (www.roarockit.com) they include more flexible cross grained veneer that would not add too much stiffness to a ski if used.

Most veneer that is big enough to cover a ski has the grain going in the long direction and this contributes greatly to the overall ski stiffness.

I agree with VinMan. Depending on the dryness and absorption qualities of the veneer and epoxy temp and viscosity, a veneer top sheet really can become totally imbued with epoxy. This makes for a really tough top layer that looks great and only requires a few coats of spar. I use peel ply instead of parchment and I get a textured surface that adds durability. I have also never seen veneer crack after it has become part of the ski matrix. I have used Tamo veneer that had cracks in it but these disappeared once the ski was pressed.

UJ, where did you find sapele veneer that is 1.5mm thick?
Is it long enough to cover the entire ski?

[UJ]

Hi Jono,
I have a fully equipped millwork and door shop (my day job) so we resaw our own veneer. Usually for 3mm thick door skins.

My door mentality had me thinking a thicker veneer better but now see the reasoning not to. And also good to know the thin is pretty tough with the epoxy.

To make it that thin I will resaw and plane to 1.5 or 2mm then grind it to 0.5mm with the steel drum on the wide belt. Most thin veneer is sliced and I wonder if the abrasive planed will behave any different.

UJ

[vinman]

I think the sanded veneer will be ok. I wouldn't sand it with anything more corse than 80-100 grit. More corse and you destroy the cell structure and leaves it too "hairy" and decreases bonding.

[UJ]

Good idea using the finer grits here. I think I read on the forum that 80 grit is best for epoxy. I might be able to plane thinner with a sled also.
I am thinking one of those Japanese fixed knife surfacers would make ideal veneer for skis.

[Upper Left Coast]

Be careful using that medipore tape for keeping inlay pieces together, we have noticed major bonding issues. We thought it was porous enough to be negligible but it creates a bit of an impenetrable layer. Use little bits of it instead of taping across letters or whatever. Otherwise agree with how veneer soaks up epoxy and becomes a pretty tough top sheet.

[vinman]

^^definitely use only what is needed with the medipore, especially on base die cuts. I personally have it had any bonding issues with it but I have good Intel that it can crest issues if too much is used.

[skidesmond]

You can buy veneer tape for inlay work. I have not tried it. I don't do much inlay work. It's cheap. I don't know how thick it is compared to medipore tape.

I use the medipore tape for holding the tip/tail spacers in place.

[Akiwi]

I use Veneer tape like this.

Usually starting with short strips horrizontally, to pull the veneer together, then a strip down the middlefor more strength.
It has a water soluble sticky surface, like postage stamps. I have never had any issues with delamination when combined with Epoxy. On the other hand, I have only used it on Longboards up till now, which are a bit stiffer than skis / Snowboards.