After the first 2 skis came out with too much camber (Kaffienes and Daddies little girl), I modified the mold to have only about 5-6 mm of camber. We were able to try out the new mold this past week and lo and behold, the camber doesn't change. Our new skis still have way too much camber (>25mm). We are thinking the thermal expansion of the materials, especially the edges, is causing the camber to increase as the edges cool and contract after pressing. One pair has titanal on the bottom and the camber is much greater than the pair without.
Is anyone else having the same problems? One thought is to reduce the temperature. Another idea is to build a negative cambered mold and hope some of camber cancels out. Other thoughts on the issue?
-kelvin
Heated Press and camber issues
Moderators: Head Monkey, kelvin, bigKam, skidesmond, chrismp
I'm no expert on the issue, but I have definatly heard that boards/ski's in heated presses should go through a heat/cool cycle before you take them out. I would guess that you should let them cool under pressure for approximatly the same amount time as you have them heated. I have also heard that the longer they cool under pressure the better the result.
James
Hello!
I cure my skis at room temp and have 10-15 mm camber built in to my moulds, the amount of camber varies with length. Sometimes I speed up the curing process by heating to ~35-40 celsius and I gain more camber, about 5 mm.
I think it is the steel edges that expand and contract different from glass laminates. The steel is the only part that my skis that are assymetrical with respect to the camber. Top sheet and base material are to soft to contribute to thermal relaxation tensions, probably.
My tip is: If you go for a heated press, optimize everything for a certain temp and stay to a certain material configuration. As soon as you differ material and/or temp you do not know what happends to your final product.
Henrik
Henrik
I cure my skis at room temp and have 10-15 mm camber built in to my moulds, the amount of camber varies with length. Sometimes I speed up the curing process by heating to ~35-40 celsius and I gain more camber, about 5 mm.
I think it is the steel edges that expand and contract different from glass laminates. The steel is the only part that my skis that are assymetrical with respect to the camber. Top sheet and base material are to soft to contribute to thermal relaxation tensions, probably.
My tip is: If you go for a heated press, optimize everything for a certain temp and stay to a certain material configuration. As soon as you differ material and/or temp you do not know what happends to your final product.
Henrik
Henrik
Professor!
Hi Henrik,Henrik wrote:Hello!
I cure my skis at room temp and have 10-15 mm camber built in to my moulds, the amount of camber varies with length. Sometimes I speed up the curing process by heating to ~35-40 celsius and I gain more camber, about 5 mm.
Henrik
At room temperature cure does your ski come out with the designed in camber or does it relax a bit? I am building 170cm skis and the mold has 15mm camber but I want the final ski to be no more than 10mm.
Thanks Tony
Hi Tony!
Yes they do, they relax 5-10 mm depending on length. I have a soft light core that does not contribute to the flex very much so you may experience differeces from my relaxation. But otherwise it sounds good with 15 mm of camber in your mold! Though I have a little less camber for a 170 cm ski, ~10-12 mm.
Good luck!
Henrik
Yes they do, they relax 5-10 mm depending on length. I have a soft light core that does not contribute to the flex very much so you may experience differeces from my relaxation. But otherwise it sounds good with 15 mm of camber in your mold! Though I have a little less camber for a 170 cm ski, ~10-12 mm.
Good luck!
Henrik
Professor!