snapping tip spacer joints left and right
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- MontuckyMadman
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For your delam under the core....are you using VDS? What type of sidewall? If Ptex are you abrading and flaming it properly?
Are you getting too much pressure in the tips with too much squeeze out creating a dry spot and a poor bond? Maybe the reason for so much resin?
Are you getting too much pressure in the tips with too much squeeze out creating a dry spot and a poor bond? Maybe the reason for so much resin?
Fighting gravity on a daily basis
www.Whiteroomcustomskis.com
www.Whiteroomcustomskis.com
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yeah i've been using the vds, but wasn't rabbeting the core out for my edges....maybe it was causing too much pressure on that area and i was losing all the epoxy? since i've just been prototyping different flex patterns i haven't been using sidewalls at all, just laminating together my core materials and leaving them square. wood sidewalls.
i always read about you guys discussing the proper ration of fabric to resin. i should try that approach also instead of just the "this should be good" approcach. i guess my only question is how do you measure out a ratio of 70/30 fabric to resin? is it as simple as placing my fabrics on the scale beforehand and literally just doing the math to figure out my resins? hopefully thats not such an a blatently stupid quesion.
i always read about you guys discussing the proper ration of fabric to resin. i should try that approach also instead of just the "this should be good" approcach. i guess my only question is how do you measure out a ratio of 70/30 fabric to resin? is it as simple as placing my fabrics on the scale beforehand and literally just doing the math to figure out my resins? hopefully thats not such an a blatently stupid quesion.
The amount of resin required for a specific fraction can be determined using a FVF calulator:
http://www.netcomposites.com/calculator ... -fractions
The final number should include an additional amount for waste and adhesion to the wood core. For good adhesion, you need a core with a moisture content of around 7%. You don't want moisture from the core interacting with the resin.
I wouldn't rely on your press to deliver the defined resin ratio. The first practical step is to build a resin impregator or something along those lines ... it can be done quite simply using printing rollers. Ideally, the roller should be 2 inch diameter.
Oh, not sure rebatting is the best method ... have a look at what Twizz did to resolve this issue.
If you haven't done so alreay, it's worth reading Springer:
http://www.skibuilders.com/phpBB2/viewtopic.php?t=4304
Second to last link. It might take a while to digest, but worth knowing.
http://www.netcomposites.com/calculator ... -fractions
The final number should include an additional amount for waste and adhesion to the wood core. For good adhesion, you need a core with a moisture content of around 7%. You don't want moisture from the core interacting with the resin.
I wouldn't rely on your press to deliver the defined resin ratio. The first practical step is to build a resin impregator or something along those lines ... it can be done quite simply using printing rollers. Ideally, the roller should be 2 inch diameter.
Oh, not sure rebatting is the best method ... have a look at what Twizz did to resolve this issue.
If you haven't done so alreay, it's worth reading Springer:
http://www.skibuilders.com/phpBB2/viewtopic.php?t=4304
Second to last link. It might take a while to digest, but worth knowing.
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- Posts: 26
- Joined: Fri Aug 10, 2012 9:25 pm
I had a problem with the cracking across the tip spacer and core line. I cut straight across. My problem with this set of skis was that I did not overlap the joint with the skis edging. In other words the edge stopped before the joint. It is my belief that if the edge were to overlap the joint between tip spacer and core you will have a much stronger ski.
Keeping in mind that I am not a engineer and do look at things from a logical perspective. This is backed up with lots of reading around here too...
ra
Keeping in mind that I am not a engineer and do look at things from a logical perspective. This is backed up with lots of reading around here too...
ra
I had a problem with the cracking across the tip spacer and core line. I cut straight across. My problem with this set of skis was that I did not overlap the joint with the skis edging. In other words the edge stopped before the joint. It is my belief that if the edge were to overlap the joint between tip spacer and core you will have a much stronger ski.
Keeping in mind that I am not a engineer and do look at things from a logical perspective. This is backed up with lots of reading around here too...
ra
Keeping in mind that I am not a engineer and do look at things from a logical perspective. This is backed up with lots of reading around here too...
ra
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After reading this again, I'm going to change my own design.
My sidewall ends and butts into my tipfill... my tip fill goes into my core an extra inch more than the thickness of the sidewall...
I suspect this is a large enough seam that a load on the nose/tail great enough has caused some delams for us.
I think I'm going to try to make the joint at an angle and stagger it, and change the tip fill shape
My sidewall ends and butts into my tipfill... my tip fill goes into my core an extra inch more than the thickness of the sidewall...
I suspect this is a large enough seam that a load on the nose/tail great enough has caused some delams for us.
I think I'm going to try to make the joint at an angle and stagger it, and change the tip fill shape
Doug
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- Joined: Tue Jan 08, 2008 6:02 am
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^ more good tips
and... if you do a two piece tip fill, for sake of saving plastic on your sheet of plastic...
don't lay the tip fill seam in the same spot as the edge seam. I always skew my edge seam about 5 teeth right or left, because i dont want the seam right were someone's gonna rest the board on the ground, or bang it into something, the tippy tip of nose/tail very prone to impact.
and... if you do a two piece tip fill, for sake of saving plastic on your sheet of plastic...
don't lay the tip fill seam in the same spot as the edge seam. I always skew my edge seam about 5 teeth right or left, because i dont want the seam right were someone's gonna rest the board on the ground, or bang it into something, the tippy tip of nose/tail very prone to impact.
Doug