Ski Builders Forum

Hello,

I'm in process of making my first press (maybe the first press in Chile). I've read her there is a lot of difference when curing the resin under heat, but at the cost of it and considering is my first attemp, i'm considering seriously.

As i understood, heat cured resin should mean stronger adhesive propierties and a harder resin. Does it means you could get a lighter ski with less resin without compromising strenght? or a stiffer ski without adding weight?
So, from your experience, how different can result a ski without a heated press?

Thanks, Emilio.

When resin gets warm it becomes less viscous (thinner), so it will ooze out easier. This means more resin gets squeezed out and you have a lighter ski.

But if you heat it up too much, it might cure before it has time to ooze out. I like to set my heat blanket to just warm (100 deg F) for a while just to heat up the resin and let most of it squeeze out, then I turn it up to 180 deg F to actually cure it.

It also varies on the resin you are using, some resins are designed for room temperature cure, while others are designed for a heated cure.

twizzstyle wrote:It also varies on the resin you are using, some resins are designed for room temperature cure, while others are designed for a heated cure.

This is the #1 factor. Typically, heat cured epoxy formulations are better suited/tailored for the ski industry. The mechanical properties (mainly flex) air designed for the cold temps that a ski will be used at.

That being said, if you choose the right room temp cure epoxy you won;t notice a difference, and it gets you building faster and cheaper. later on you can always buy blankets, just plan for whatever heat source you want to use while building your press.

twizzstyle wrote:When resin gets warm it becomes less viscous (thinner), so it will ooze out easier. This means more resin gets squeezed out and you have a lighter ski.

But if you heat it up too much, it might cure before it has time to ooze out. I like to set my heat blanket to just warm (100 deg F) for a while just to heat up the resin and let most of it squeeze out, then I turn it up to 180 deg F to actually cure it.

It also varies on the resin you are using, some resins are designed for room temperature cure, while others are designed for a heated cure.

But apart from viscosity or curing time, can i get the same result with a heated press than a with non-heated one? (using the proper resin for each use, obviously)

krp8128 wrote: This is the #1 factor. Typically, heat cured epoxy formulations are better suited/tailored for the ski industry. The mechanical properties (mainly flex) air designed for the cold temps that a ski will be used at.

That being said, if you choose the right room temp cure epoxy you won;t notice a difference, and it gets you building faster and cheaper. later on you can always buy blankets, just plan for whatever heat source you want to use while building your press.

Good to hear that.

I have used room temp epoxy on all skis and boards so far and have not had a problem with lay-up or the performance of the skis.
There is a big cost for the blankets and remember that there is a life span for the blankets. Maybe some of the builders here can correct me on this but the blankets can be fragile when pressing... Just food for thought. I would agree with krp that if needed, later you can upgrade your process to heat the press.
I heat the room the press is in durring the winter to help with the curing process and use west systems epoxy.
Good luck with the building!
ra

I fully agree with the above!
And from my book of experience(again): Don't forget(underestimate) the "after cure" process! Which takes between a week or two, in room temperature. Just because the surface of the epoxi feels hard and robust it is only done by 70 - 80%. There are loooong molecules forming here. But when they are done, almost unbreakable!.. It is Also depending on what type you are using and brand. Check with the manufaturer.

Cheers

Underfloor carbon heaters work cure and or post cure - depending on your epoxy. Electric blankets can be made to work, although I would use them post cure. 'cheap heat' or is it 'cheap heat alternative' as search terms should yield some good results.

Good luck with your build!

Thanks for all your advices. Now i have more money for materials and more prototypes.