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heat blankets

Posted: Sun Jan 22, 2012 8:10 pm
by infinityskis
I am new to ski building and what exactly does a heat blanket do? how is better that a press without heat? thanks

Posted: Sun Jan 22, 2012 8:16 pm
by nate
The undeniable advantage is that heat makes the epoxy cure faster. A 4-6hr cure can be turned to 45 minutes. Heat also helps the epoxy cure better, resulting in better mechanical properties. Stronger, more durable, etc.

It has been debated here lately whether the 45minutes of heating during curing is actually doing the second part of that, ie making it stronger. I'm inclined to believe that where the increase in strength really becomes evident is when heat is added as a post-curing process. Ie press until epoxy is hard, then heat for 3-4 hrs after that.

Posted: Mon Jan 23, 2012 1:12 am
by chrismp
it really depends on the epoxy you want to use. read the recommendations of the manufacturer and you'll know if a heated initial cure or postcure are beneficial for your epoxy system.

Posted: Mon Jan 23, 2012 1:42 am
by Dr. Delam
One of the huge benefits that I use it for is to modify camber. With a flat mold I can get camber if I heat from the bottom, reverse camber heating from the top, and a flat ski with top and bottom heat.

Posted: Mon Jan 23, 2012 6:29 am
by twizzstyle
It completely depends on the epoxy you are using. Some epoxies cure at room temperature, some require elevated temperatures. Really, most (all?) epoxies will cure at room temperature regardless of if they require heat, but it may take a very long time and you'll have suspect bonding/strength.

I would say that ideally you should be using a heat-cure epoxy (one specifically advertised as being for compression molding), and whatever temperatures the manufacturer recommends. But then again, there are many on here that use room-temp cure epoxies with great results.

Also there is nothing wrong with using heat on a room-temp cure epoxy, it will speed things up and improve wetout (less viscosity), just don't overheat... you don't want the epoxy to cure TOO fast.