A new ski is here! A new ski is here!

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skidesmond
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A new ski is here! A new ski is here!

Post by skidesmond »

I am finally an official ski builder. I pressed my first ski yesterday. :D I wish I could say it came out the way I had it pictured inmy mind :( I'm looking at this ski sbuild as a learning experience. Not sure if they are worthy of bindings or not but I may put some on just to learn how. I had planned to make them for a ski area I work at for their 75th anniversary. WWeelll.. I will make them a pair but not these.

I started researching the ski building process back in april/may this year. This sight has been great and couldn't have gotten this far w/ out it. I knew it was a big project but there was always more to learn/research at every turn.

I got my press done about a month ago.

Last week I had a major set back. I was getting ready for the build, double checking my supplies and work space. I noticed my cores I made weren't symetrical. I used SnoCADX to design the ski. I printed the core and base layouts in split pdf format. Then printed 7 sheets of paper that I
carefully taped together. I used that to make my first template for the cores and I had made 4 cores of varying sizes and dimensions. I later read in the forum that printing that way is risky and just to send the full size pdf file to Staples and they'll print a full size print on their plotter. So I emailed the pdf files to Staples and picked it up about 1 hour later. It was perfect! Cost was less than $2 a print. Well worth it!

So I spent friday night, saturday and sunday making new templates and a new core. I also planed down enough wood for 3 more cores.

For this build I wanted to keep it some what simple (if
there is such a thing ;) . Here's some specs of the build:

-Epoxy by QCM EMV-0049 resin with ECA-032 hardener. Made 3 separate batches. Each batch consisted of 8oz resin with 2 oz hardener.
-ski dimension 118-65-104 used snoCADX
- 4001 black p-tex from skibuilder.com
- triaxial FG 22 oz from skibuilder.com
- VDS rubber from skibuilder.com
- solid ash core, single piece of ash no glue up
- cotton cloth for topsheet
- vellum paper for graphics
- no tip or tail spacers
- wax paper
- packaging tape
- protective gloves
- pneumatic press approx 40 psi

The layup was pretty typical. I used clear packaging tape on the p-tex base to protect it from the epoxy. I used 1/8in hard board (the dark brown board) and covered it w/ wax paper to keep epoxy from sticking to it to do the lay up. I started using a spreader and found that doing with my hands was faster. Luckily I had box of latex gloves at the ready. The epoxy has a pot life of 25 minutes so I had to work quickly. It was my first time working w/ epoxy. It can get real messy quick. I thought it was kind of thick. There was almost no odor, but have good ventilation and wear a mask.

So now my layup is complete. The top sheet is on with the graphics and final layer of epoxy. I cover that up with wax paper and another layer of 1/8 in hard board and insert it into the press. But it won't go in! The cat track got in the way and caused the skis to shift a bit and wrinkle my top sheet. Unfortunately I didn't check it so I didn't see the big wrinkle until I took the skis out. That was a big disappointment!! :( :x

So the skis are pressing.... I left them in the press for about 10 hrs. The press had a couple small air leaks. I could hear the compressor coming on every 5 minutes. I tighten up some of the clamps/bolts/air connectors and that took care of it. I think it came on 1 once after that.

Skis hot off the press.
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Notice the core shift on the tail of the ski.
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Skis are separated.
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The bases came out pretty good. Peeling off the packaging tape took awhile but was worth the effort.

Now the top side. The left ski has a big wrinkle on the left side. Not real clear in the pic (crappy camera) I'lll post better ones tomorrow:
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Graphic pics. These were real disappointing. In a trial test it looked like the vellum paper would "melt" like rice paper. It doesn't. You can also see the wrinkle in the top sheet on the left ski.
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Tails
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The graphics should look like this:
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btw- I came up with the name SECTION8 from the show MASH. More than once I thought I was crazy for trying to build skis.
:D

Things that went well... The press worked well. The edges and base came out good. Next time I will do a full wrap around the tip.

The skis also came out extremely stiff!! The core was 12-13mm of ash. I need to make a new planer crib because the skis did not taper enough toward the tip and tail and were too thick. It takes a lot to bend them. Surprisingly they are not that heavy.

So it was a good learning experience.

I'll be making more cores this weekend. I'm hooked now!! :D
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KevyWevy
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Post by KevyWevy »

great first try. its always a learning experience. i'd say mount them up and test them out at the beginning of the season. that way you can really feel the stiffness and go from there.

what i've started using instead of packing tape on the bases, is contact paper. its easier to peel off since its only one piece. try that next time. :)

also, think about using alignment dowels to keep your core from shifting. this has worked great for me.

if you're making a new planer crib, make it adjustable. here is a picture of mine half way through a core. the bottom blocks are interchangeable and only hot glued in for temporary use.
http://students.washington.edu/kevinl3/IMGP4959.JPG

that way all you have to do is plane down new blocks for each different profile you come up with.
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MontuckyMadman
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Post by MontuckyMadman »

You gonna ride those at wa-wa-wa-wachusett?
skidesmond
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Post by skidesmond »

Thanks for the advice. Much appreciated. I will try your suggestions over the next week. I found a great video the other night. I should have stopped and took the time to try it out before pressing. Live and learn.. ...

I will definetly tune the lay up process and the core shaping. I think a 10mm ash core w/ 2mm in tip and tail will provide a more flexiable ski. I think I'd rather have a ski a bit soft than rock hard. This is as stiff as wood decking. :D

Maybe I will scavage the bindings from my old K2s. More skis to come!
skidesmond
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Post by skidesmond »

Blandford Ski Area, if I put bindings on them. I'm making a pair for their 75th anniv. More as a commemorative piece but would like them to be skiable. I joked that if they sucked we could mount them over the fireplace and if they were really bad we could through them in the fireplace. :D
knightsofnii
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Post by knightsofnii »

That's pretty good for a first try! And to start research six months ago and already be building with a pneumatic press? Very worthy.

I wish I had built a press from scratch, though I probably would have underbuilt it a little I would have saved a fortune. We've modded and modded and rebuilt this thing at least 3 times now.

If you're going to build a bunch of skis, might as well get some 18 or 16ga steel sheets for your "cassette" instead of mdf/hardboard, then you dont have to mess around with wax paper, etc...

Build a shelf even with the height of your mold on the press, that way you can slide the cassette in, or you can slide the mold out, place in the cassette and push the whole thing in. This is our next project. Though we need an adjustable height shelf. Side loading boards/skis yourself is a bitch. We wrap the ends of our steel sheets with duct tape to keep stuff from moving around, we initially did it to protect the heat blanket more from puncturing
Doug
skidesmond
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Post by skidesmond »

Thank! I couldn't have done w/o this forum and all the knowledge people who experimented before me.

I already have a list of tweaks and improvements to start on. First is a new planer crib the gives a better profile. My current one doesn't taper enough making the skis extremely stiff. Had the skis came out as stiff as the core was all by itself would have been doing the Happy Dance. So at least now I know the effects of fiberglass and epoxy.

I like the shelf idea. The less distance I have to carry and move the cassette the less chance of things shifting. And of course a method the keep the core centered over the base. Lots of ideas here in the forum.

Need practice bending the edges. I have a hand bender which works ok. I've seen some nice ones in the forum. Eventually I'll make a better one than what I'm using now. It's getting the right bend near the tip, last inch or so, that seems the hardest. It looks much nicer when a ski has a full edge around the tip.

Couple more HD Bungy chords to hold the cat track up. Tweak the tip/tail molds so the hose fits better in the bend.

Since the skis are experimental, I'm going to coat the top w/ acetone and Plexiglas and see how it looks. Might make a nice top sheet. Acetone melts the Plexiglas into a polyurethane like liquid.

I'm also thinking about making a flexible jig to make core/base templates. Or skip the templates altogether and just use the jig as the template. That's when I have more time. I don't need that right away.

So I'll be busy for a little while. ;)
skidesmond
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Post by skidesmond »

Figured I'd just add to this thread instead of starting a new one.....

I made some tweaks. Re-configured the planer crib and made a better edge bender. Very low tech/low budget bender. I'll be making one like Skeviks, using Twizzstyle drawings as a guide:
viewtopic.php?t=2069

So the results? The skis are more flexible than the last ones. Could still be a little softer overall but they're better. Out of the press they looked good. The bases looked good and I wrapped the edges around the tip this time and that looked good. After I cut the flashing off I noticed the top sheet wrinkled/crinkled again!! In the same place on the skis before. ARGH!!

I took extra care in the layup and everything aligned, as far as I could tell. I used double stick tape on the base to prevent them from moving. So from the layup table to inserting into the press things must have gotten messed up. I used zip ties to hold the cassettes in place so that wouldn't move. But the layup must have shifted in between the cassette somewhere along the way.

Before I cut the flashing off I checked the base and the double stick tape kept the bases in place. So the core and fiberglass moved. I think I may also be leaving too much fiberglass over hanging in the lay up which could be causing it to get wrinkle up when I slide it into the press.

I didn't use offsets or dowels in the layup. BIG MISTAKE!!!!! I didn't fully understand how the dowel system worked. This morning I did a search on "dowel" in the forum and found some great examples/pics of how it works. I thought some folks were drilling a hole through the base and core. I certainly didn't want to drill a hole in the base. So I just abandoned the dowel system. As for the offsets I thought they would get in the way of the layup and figured if I was careful I wouldn't need either system. WRONG!!!!! YOU NEED SOME KIND OF SYSTEM TO KEEP THINGS FROM SHIFTING.

Now I see that the dowel is super glued onto the base and aligns with a hole in the core. I'll use this method in the next pair.

As for the wrinkle/crinkle? I didn't want to waste another pair skis so I thought perhaps I could fix them with a new topsheet. I took my first pair of skis (since they are now experimental skis) and put the belt sander to the wrinkle/crinkle and sanded down to the fiberglass, just to see what would happen. It sanded out smooth.

So I did the same to my second pair.... The sander did a good job. I took the wrinkle out and then lightly sanded the rest of the topsheet, which is cotton w/ epoxy. I plan on adding another cotton topsheet with epoxy and throwing them back into the press tonight or within the next couple days. Hopefully I'll get a decent result.

As for the graphics I used rice paper this time instead of vellum. The results were about the same. Both papers shows up too much with the dark blue topsheet. I think either paper will work ok with a lighter color topsheet.
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MontuckyMadman
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Post by MontuckyMadman »

good stuff, dowels work well. Make the hole slightly bigger than the dowel otherwise in layup it may be hard to slid the core on. Don't forget to cut a hole in your bottom glass for the dowel.
Use spray adhesive to hold the base down, no impression or dent and works great on AL.
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nate
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Post by nate »

An alternative to the dowel method that is using a couple inserts. (if you're using inserts already) Just superglue down 2 of your inserts to the base material before layup, then when you go to layup you can just slide the holes in the core over the inserts. Basically the same as the dowel method but you're using holes that would already be in your core.
skidesmond
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Post by skidesmond »

Thanks guys for the tips. I think the dowels will solve most of my problems.

I was able to put a new topsheet on today. It came out ok. Some very minor wrinkles that I live with, probably from the wax paper.....
Not going to worry about it.

I found the causes of the large wrinkle/crinkle problem. First my cassette could be a bit wider. Second, too much fiberglass and top sheet over hanging when laying up the skis. It was getting caught on the cat track and tip block when I was inserting the layup into the press. It happened again when I went to re-press the ski w/ the new topsheet. But this time I saw it happen and fixed it.

I'll cleanup the ski later this week.

So before I make anymore skis I need to finish tweaking the press by using more heavy bungy chords to pick up more of the cat track, add some material to the cat track so it's longer, round the top of the tip/tail blocks for a better fit w/ the air hose... etc. Do some trial runs.... THEN make another pair of skis.

Thanks everybody for the tips!
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