What's the bend radius on your tip ?
I had issues with a pair once as the tip radius was too tight (less than 100mm in the very end): a dry pressure test to see if the bladder conformed the mold seemed OK but in the end it was not. Now I keep my tip/tail mold radius above 200mm and I know I have a consistent pressure all over the mold.
If I ever go smaller again I do have a solution though, I'll try to take pictures tonight.
Pre-bending your wood core is a pretty easy thing, have a look at my journal, on my first pairs I used to do it. I made a simple jig to hold the core bent, sprayed some warm water on it (just a slight mist) and force drying with a heat gun, repeat a few times and you're good to go. The core will "relax" for sure but still, it helps a lot (I was using vacuum at this time, with almost full wood core). Just make sure your let the bent core dry completely before you proceed with the layup, epoxy and water don't like each other.
Did you pre-bent the edges vertically ? It also helps, even with a pneumatic press I still do it...
Section8- GS Comp ski
Moderators: Head Monkey, kelvin, bigKam, skidesmond, chrismp
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skidesmond
- Posts: 2337
- Joined: Tue Apr 07, 2009 3:26 pm
- Location: Western Mass, USA
- Contact:
The tip radius is 300mm (according to my sno-Cadx design), the tip blocks s/b pretty close to that.
I haven't tried prebending anything yet but will be doing tests on this. I'll give the bending of the core tip a try. I really want to get this worked out. I think having a full wood core is a way for the ski to stand out among most of the others. Granted it takes a little more TLC in caring for the ski over time. I've thought about resurrecting the steam box to bend the tips. But that takes up a lot of room and I really don't want to be steaming cores indoors this time of year.
I measured the ski tip and the final thickness is almost 8mm. The core itself is 3mm. I think I said it was 2mm but it's 3mm. So I'm going to get the core tip down to 2mm by sanding it down next time. Getting a core to 2mm w/ my planer is risky.
The edges are bent to conform to the shape of the base so there is no tension when I glue them. But I haven't been bending them vertically.
So, things I'll be trying are:
1. thinner core tip, 2mm
2. prebend base/edges
3. prebend core tip
I'll check out your journal. Thanks.
I haven't tried prebending anything yet but will be doing tests on this. I'll give the bending of the core tip a try. I really want to get this worked out. I think having a full wood core is a way for the ski to stand out among most of the others. Granted it takes a little more TLC in caring for the ski over time. I've thought about resurrecting the steam box to bend the tips. But that takes up a lot of room and I really don't want to be steaming cores indoors this time of year.
I measured the ski tip and the final thickness is almost 8mm. The core itself is 3mm. I think I said it was 2mm but it's 3mm. So I'm going to get the core tip down to 2mm by sanding it down next time. Getting a core to 2mm w/ my planer is risky.
The edges are bent to conform to the shape of the base so there is no tension when I glue them. But I haven't been bending them vertically.
So, things I'll be trying are:
1. thinner core tip, 2mm
2. prebend base/edges
3. prebend core tip
I'll check out your journal. Thanks.
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skidesmond
- Posts: 2337
- Joined: Tue Apr 07, 2009 3:26 pm
- Location: Western Mass, USA
- Contact:
So I raced on them last night. Ha-ha, I should have skied a bit on them first to get the feel for them before jumping into the starting gate. I've been skiing a 168 (homemade) and a 170 ski (Fischer). These are 180cm so a bit longer.
Snow Conditions - Good ol' fashion eastern hard pack with mini ice chunks scattered around (we need some real snow!) and some loose frozen granular. Once the ice chunks were pushed aside it wasn't too bad. Very fast conditions. And they were making snow as well.
The race - The first run was horrible. First race jitters. Hard time staying on line half way through the course. Second run was much better.
The ski - Need some more time on them but not as stiff as I thought they would be, which is fine. They carve nicely, hold a good edge. I think if I made this ski a 168cm like my others it would be very stiff w/ the all maple wood core and extra fiber glass/carbon fiber layer. I think I'm going to like them. Will be skiing on them more this weekend.
Snow Conditions - Good ol' fashion eastern hard pack with mini ice chunks scattered around (we need some real snow!) and some loose frozen granular. Once the ice chunks were pushed aside it wasn't too bad. Very fast conditions. And they were making snow as well.
The race - The first run was horrible. First race jitters. Hard time staying on line half way through the course. Second run was much better.
The ski - Need some more time on them but not as stiff as I thought they would be, which is fine. They carve nicely, hold a good edge. I think if I made this ski a 168cm like my others it would be very stiff w/ the all maple wood core and extra fiber glass/carbon fiber layer. I think I'm going to like them. Will be skiing on them more this weekend.