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Vacum press air bubbles

Posted: Mon Feb 10, 2020 11:12 am
by barnaba
Hi, I'm new to this group :)
I hope you will be able to help me.
I have made about 20 snowboards and a few pairs of skis so far, but in some bards I have a problem with air bubbles between the fiberglass and base material. These air bubbles only come out where the bending of the nose and tail begins.
I use a heated vacuum press (up to 80 celcius degrees, 0,9 kg per cm), 2mm aluminum sheet and base material, fiberglass, woodcore, carbon fibers, verneer etc.
Has anyone had a similar problem?
I will be grateful for any help :)

Re: Vacum press air bubbles

Posted: Tue Feb 11, 2020 3:01 pm
by vinman
Air bubbles in the base or topsheet are most likely due to inadequate pressure.

Re: Vacum press air bubbles

Posted: Wed Feb 12, 2020 8:53 am
by Hannes
I had that problem once. I am using a vacuumsetup as well. During pressing the suctionhose got clogged with fleece and resin so the gauge told me everything was fine, but it wasn´t. since then I use a long hose with several holes in it.

Re: Vacum press air bubbles

Posted: Fri Feb 21, 2020 10:27 am
by OAC
Hi

I guess you're aware of that vacuum "apply pressure"/acting from all directions. Above, under, side and all other angels. I don't know how you're final set up looks like (pictures..?). What are you using, in the press or in the bag, on top of your skis/boards? Do you have the paper, that's in the picture, under the mold during vacuum?
And keep in mind that the (epoxy) curing process also produces gas and heat.
In my experince, it's super important to ensure that the air can easily be evacuated from the bag. My setup contain no paper or likewise under the mold that can block the way the air takes. I'm using a polyester felt over the laminate area. It acts like a breather. It works for.
Just a tip. :)

Re: Vacum press air bubbles

Posted: Sun Apr 26, 2020 12:17 pm
by TimW
Bit late reply maybe...

Anyway, it seems to me that the transition from the mold base to the mould nose section is not smooth enough. If there is a bit of a kink, the core cannot follow the curvature and there will be no pressure below the core.