Vacum press air bubbles

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barnaba
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Joined: Mon Feb 10, 2020 9:58 am

Vacum press air bubbles

Post 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 :)
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vinman
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Re: Vacum press air bubbles

Post by vinman »

Air bubbles in the base or topsheet are most likely due to inadequate pressure.
Fighting gravity on a daily basis
www.Whiteroomcustomskis.com

Hannes
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Joined: Wed Nov 09, 2011 2:20 am
Location: NRW, Germany

Re: Vacum press air bubbles

Post 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.

OAC
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Re: Vacum press air bubbles

Post 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. :)

TimW
Posts: 3
Joined: Sun Apr 26, 2020 11:56 am

Re: Vacum press air bubbles

Post 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.
Last edited by TimW on Sun Apr 26, 2020 12:18 pm, edited 1 time in total.

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