Blue Cheese
Moderators: Head Monkey, kelvin, bigKam, skidesmond, chrismp
Blue Cheese
Over the summer I completed my first "Pair" of skis with moderate success: http://www.skibuilders.com/phpBB2/viewt ... c&start=15
The first ski came out mechanically sound, but with cosmetic issues. The second ski never really came out; my vacuum pump malfunctioned and I had no backup. There were gaping voids in my sandwich.
So i tried it again, starting with a new adjustable mold, made plenty wide. It is 18" wide, which gives me around 16" of room for skis plus an inch on either side for sealing the bag. It's covered in a thick sheet of Formica, smooth and airtight. I taped of the sealing surface and applied a release wax.
I must have done something right when I cut out the bases and attached the edges, everything sat perfectly flat on the mold.
Alignment block are a PITA, and I can't pin the cores due to the mold needing to be airtight. So I used an 1/8" dowel to make some alignment pins:
Here are the skis, all ready to be wrapped up:
I kind of took a big leap of faith here and decided to do both skis at once. I had little faith, so I skipped over printing and applying graphics. Ooops.
I sealed the bag up, located the leaks, and then placed the "Eazy Bake Oven eXtreme" over the mold. A 3/4" particle board enclosure placed over the mold with two 150w heat lamps inside. No idea on the actual temp, put it got past toasty in there. For some reason I had fluctuating vacuum throughout the day, it would plummet when I turned the pump off, but other times it would hold for over an hour. I checked on everything and then ran the pump a bit until 10pm when the rest of my family went to bed.
When I checked on everything in the morning, the gauge read 5" HG vacuum, put the bag was still as tight as could be. I think my brand new gauge is defective. I opened everything up to find this:
Success!
Here they are all cleaned up and mounted:
Oh yeah, we got 10" of powder at my parent's on Monday morning, and are looking to get 12-16" tonight. When I took this pick there was already 4" fresh on the ground. I think I'll skip work to go skiing tomorrow .
Specs:
114-75-104, 172
15.7m radius
Mr. Fiberglass SLOW epoxy
VDS along edges, in tip and tail
22 oz triax
UHMW Tip/Tail Spacers
Cherry and White Pine core, with Cherry Sidewalls
VDS in binding area (~20")
22 oz triax
Cotton graphics
3 oz. woven glass
They ideally need a base grind, but I sharpened them Up a bit and threw on a coat of wax so I can play with them tomorrow.
The first ski came out mechanically sound, but with cosmetic issues. The second ski never really came out; my vacuum pump malfunctioned and I had no backup. There were gaping voids in my sandwich.
So i tried it again, starting with a new adjustable mold, made plenty wide. It is 18" wide, which gives me around 16" of room for skis plus an inch on either side for sealing the bag. It's covered in a thick sheet of Formica, smooth and airtight. I taped of the sealing surface and applied a release wax.
I must have done something right when I cut out the bases and attached the edges, everything sat perfectly flat on the mold.
Alignment block are a PITA, and I can't pin the cores due to the mold needing to be airtight. So I used an 1/8" dowel to make some alignment pins:
Here are the skis, all ready to be wrapped up:
I kind of took a big leap of faith here and decided to do both skis at once. I had little faith, so I skipped over printing and applying graphics. Ooops.
I sealed the bag up, located the leaks, and then placed the "Eazy Bake Oven eXtreme" over the mold. A 3/4" particle board enclosure placed over the mold with two 150w heat lamps inside. No idea on the actual temp, put it got past toasty in there. For some reason I had fluctuating vacuum throughout the day, it would plummet when I turned the pump off, but other times it would hold for over an hour. I checked on everything and then ran the pump a bit until 10pm when the rest of my family went to bed.
When I checked on everything in the morning, the gauge read 5" HG vacuum, put the bag was still as tight as could be. I think my brand new gauge is defective. I opened everything up to find this:
Success!
Here they are all cleaned up and mounted:
Oh yeah, we got 10" of powder at my parent's on Monday morning, and are looking to get 12-16" tonight. When I took this pick there was already 4" fresh on the ground. I think I'll skip work to go skiing tomorrow .
Specs:
114-75-104, 172
15.7m radius
Mr. Fiberglass SLOW epoxy
VDS along edges, in tip and tail
22 oz triax
UHMW Tip/Tail Spacers
Cherry and White Pine core, with Cherry Sidewalls
VDS in binding area (~20")
22 oz triax
Cotton graphics
3 oz. woven glass
They ideally need a base grind, but I sharpened them Up a bit and threw on a coat of wax so I can play with them tomorrow.
Hi,
Nice looking skis!!!.
I'm curious about your mold. How do you attach the formica to an adjustable mold. I am assuming that the formica is removable so the mold can be adjusted. Do you have any problems with is cracking at the tip radius? I've used acrylic plastic clamped to the mold but it breaks on occasion and it's pretty expensive to be breaking.
Thanks
bill
Nice looking skis!!!.
I'm curious about your mold. How do you attach the formica to an adjustable mold. I am assuming that the formica is removable so the mold can be adjusted. Do you have any problems with is cracking at the tip radius? I've used acrylic plastic clamped to the mold but it breaks on occasion and it's pretty expensive to be breaking.
Thanks
bill
Right now the Formica is one continuous sheet. The plan is ti use either a dremel or a sharp knife to cut along the tip and tail blocks when the time comes to adjust the mold. I will then use silicone to seal the joints at the new center section.breid19 wrote:Hi,
Nice looking skis!!!.
I'm curious about your mold. How do you attach the formica to an adjustable mold. I am assuming that the formica is removable so the mold can be adjusted. Do you have any problems with is cracking at the tip radius? I've used acrylic plastic clamped to the mold but it breaks on occasion and it's pretty expensive to be breaking.
Thanks
bill
I was worried about the cracking as well, so I used a heat gun as I was bending and gluing everything down. It worked out great, and this was a thicker then normal cover sheet (they put these down as a sacrificial layer when they ship a pallet of Formica).
Amazing.bigKam wrote:nice looking skis! so, how did they work?
First day out, January 2nd, Sunday River ME. I did a very rough tune to 1/3 edge bevels, no basegrind. I was able to find plenty of waist deep untracked in the woods. Somehow, I think I nailed it with these, I just look between the trees and go. Nice and smooth in the bumps too. They ride about 6" down in the snow, perfect for faceshots.
Later in the day I moved tothe other side of the mountain and found that the wind had blown much of the snow of the upper slopes. Considering the bad tune and high bases, these skis had respectable edge hold. Not the greatest, but very manageable.
I was able to work in a basegrind and tune at the shop. The tech was a bit worried aout the edges coming out, but it turned out to just be spots where my edges were not perfectly bent to match the base. We were still cautious though, I wish we had ground a bit more. I'm still slightly base high in spots, due to the edges. I need to run a few sample pieces/cross section to better understand what is going on when the edges and glass meet the core. I don't want to go to deep with the recess, but obviously this time I was a bit shallow. I think that as the core thins out, itr deflects to meet the edges better, as my high spots appear my underfoot then anywhere else. The tune is OK, I really should have done it at home myself, but I was swamped with schoolwork and trying to pack for a trip, so I didn't have time.
Second day out, January 26th, Smuggler's Notch VT. About 6-8" inches of fresh, on top of crap from the last warm spell. Ski are again awesome in the soft. The edge hold seems to have been reduced a bit. The tips are not as torsionally stiff as they need to be, a little sloppy on the high angle carves on hardpack. I did make it down a trail that was pure windblown boilerplate, the skies are capable, but not designed for the ice. Damp though, my tips are covered in VDS about 8" back.
In summary, these skis rock in the soft snow and trees. Fortunately, that is exactly what I was going for when I set on on this little adventure, so all is good. For next time, I need to:
- 1. Dial in the recess for the edges
2. Work on torsional stiffness.
3. Add about 10 cm. In a softer ski, I think I'd like to go a bit longer. For the hell of it, I may go a bit wider too, for those odd east coast dumps.