Cornice Skis

falls · Post by **falls** » Mon Sep 24, 2012 4:41 am

You need masking tape as wide as your topsheet. It's much like masking tape only wider. Usually called application tape (often used to apply vinyl stickers). Comes in clear or the masking tape papery yellow colour.
Well done on the first press.
Protect those heat blankets! They're tough if you look after them right but very fragile if you don't.

ben_mtl · Post by **ben_mtl** » Mon Sep 24, 2012 6:02 am

Hi Cornice, what glue did you used to bond the UHMW sidewalls to your wood core ? epoxy ?
For you final crib did you go with double sided tape only or grip tape + double sided tape ? Personnaly I just glue son sheets of 80 grit sand paper onto the crib surface and nothing moves when profiling excepts maybe the tips could benefit more support when they're close to the "2mm thin" target... I'll dig the tape for this area !

Also, regarding the "Boheme profiler crib", the stopper at the tips looks like it's aluminum (and maybe you've noticed the stopper also prevents the core to move side-to-side). I'm a bit perplex about it, I would be scared to risk "planning" this piece of Aluminum ! (they use a sander though.. might be less of a concern for them...) An MDF stopper would have to be changed quite often I guess (with snipe and all that on a planer)

Cornice · Post by **Cornice** » Thu Sep 27, 2012 10:33 pm

Falls- Thanks ordered some of the tape you suggested.

ben_mtl- I used double sided carpet tape only. Actually it was permanent laminate tape and it was WAY too strong. It was a pain in the A to get the core off. The sidewalls were glued on with poly. glue. I tried the grip tape only but the tips kept getting sucked into the planer. It seems allot of people use just grip tape, maybe its just my planer?

Update-
I intended to press my first pair of skis today. The cores are prepped and looking mighty fine. All my materials are cut. The press metal sheets are extended to save the heat pad. The bases have edges glued on.
OOOPPPSSS Major F UP. How did i cut one base goofy? The bases were double sided taped against my wood template and cut out. I some how stuck one down skewed. That was my last bit of base so until i get some new base material this project is on hold. Thinking of building a vacuum table now.

MontuckyMadman · Post by **MontuckyMadman** » Thu Sep 27, 2012 11:46 pm

it warped.

vinman · Post by **vinman** » Fri Sep 28, 2012 2:39 am

It can warp and or you didn't have it truly flat. To make sure it is flat, I usually cut the base material off the tool about a day before I want to cut them to shape. I leave the material under some MDF or hard wood to help it flatten and relax.

When I go to stick the template to the base I put the base material on top of some MDF, on the workbench , apply the tape to the template and then press the template down on the base material. I feel like this way I can't lay the base material down funny and get some sort of minor bubble in there that causes the bases to be wonky.

skidesmond · Post by **skidesmond** » Fri Sep 28, 2012 4:18 am

I've had the same issue on the fist few pairs. The p-tex can warp. Of course I didn't know this until I had pressed the skis and finished them. When I put the skis together the middle was off by a 2-3mm. I skied them anyway. Now they stand in the corner of the basement.

Do what Vinman suggests. I also put the edges on asap after I cut the base. So have the edges already shaped. I also leave the base w/ edges on the template until I'm ready to press.

powderho · Post by **powderho** » Fri Sep 28, 2012 6:12 am

Cornice wrote:Thinking of building a vacuum table now.

You still have to be very careful with the vacuum table. I have found that it's almost easier to suck the material down crooked using vacuum. It almost pulls too hard on the material and can easily twist it. It really helps to let the base material relax and lay flat on it's own first. You also have to be careful to avoid temperature fluctuations. If I cut out some bases in my garage and leave them in there overnight (and the temp drops 30 degrees) they will warp by the next day. There is a reason most places layup the skis shortly after the base material is cut out. You can still salvage the base material if it isn't too bad. Just make sure you use the base template to glue your edges on. You can kind of force the base back into shape. You might need to heat up the material a tiny bit and you probably need to use more super glue to hold the edges on than you should.

vinman · Post by **vinman** » Fri Sep 28, 2012 8:06 am

I've just found local guy that will CNC cut my bases. $30 for a the first pair of a certain shape, $15 for the next pair of the same shape. The extra $15 is for him making the cut file. Seems pretty reasonable.

powderho · Post by **powderho** » Fri Sep 28, 2012 2:10 pm

Vinman wrote:I've just found local guy that will CNC cut my bases. $30 for a the first pair of a certain shape, $15 for the next pair of the same shape. The extra $15 is for him making the cut file. Seems pretty reasonable.

Why not just get a template cut for $30? You would save a bunch of money. You can still end up with warped bases even if they are perfectly cut out. The only reason I would consider this is because it makes such a mess cutting out the base material.

ben_mtl · Post by **ben_mtl** » Fri Sep 28, 2012 2:45 pm

powderho wrote:Why not just get a template cut for $30? You would save a bunch of money. You can still end up with warped bases even if they are perfectly cut out. The only reason I would consider this is because it makes such a mess cutting out the base material.

"router dust collection system" is your friend ! I'll take pics of my high tech plastic chips collector next time I use it !

vinman · Post by **vinman** » Fri Sep 28, 2012 4:46 pm

I can get the template cut CNC for about 40 plus material, but for the guys I'm building for, it is just easier to have the bases cut and have them pay for it instead of me. I may have some select shapes CNCd but it is too much right now to have the number of shapes I'm building this year to get done this way.

Cornice · Post by **Cornice** » Fri Sep 28, 2012 8:18 pm

Wow that makes sense. One base is perfectly to shape of the template and the test ski. The other warped one i let sit for a week before i put edges on. I tried to remove the edges but they are glued on amazingly well. Looking at the other base i cut about a month ago i see its all wacky wavy tube man.

Is it even good enough to attach edges to bases right when they are cut out? Or do the bases warp from stress relief right when they are cut out? Hmmm i guess they probably do but results must be acceptable since thats what yall do.
It probably does not help that i dont heat the shop all day.

MontuckyMadman · Post by **MontuckyMadman** » Fri Sep 28, 2012 9:56 pm

DOH!
last step is cut base and edge. then layup.
warpage is immediate.
clamp to template after cutting with many clamps and let stabilize. edge soon.
clamp other ski to similar template and keep straight while edging each ski.
clamp to template when done.
glue to casstte and align right before layup.

sammer · Post by **sammer** » Sat Sep 29, 2012 7:38 am

MontuckyMadman wrote:DOH!
last step is cut base and edge. then layup.
warpage is immediate.
clamp to template after cutting with many clamps and let stabilize. edge soon.
clamp other ski to similar template and keep straight while edging each ski.
clamp to template when done.
glue to casstte and align right before layup.

THIS^ is why I wouldn't pay to have bases cnc cut offsite.
Out of the cnc shop, into your car, to your shop, store for a couple days.
It seems to me bases would be pretzels by the time you were ready to use them.
Consistent temperature is your friend when it comes to base material.
This is why I no longer heat my work area in the dungeon.
The temp down there varies from 15c in the summer, down to about 12c in the winter.
Over all the temps stay pretty consistent. (day to day, day to night)

sam

powderho · Post by **powderho** » Sun Sep 30, 2012 6:34 am

I've brought my base material (with edges attached) into the garage from inside, taped them to my aluminum cassette (which was freezing), and watched the bases warp so much the edges pulled away. This took about 60 seconds.

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