Hollow P-Tex

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Hannes
Posts: 87
Joined: Wed Nov 09, 2011 2:20 am
Location: NRW, Germany

Hollow P-Tex

Post by Hannes » Sun Dec 01, 2019 7:37 am

Yesterday I laminated a Touringski. Vacuumpress, -0.9bar. Resin like always, HP-E110L. Cores with rabbet for the edges. Edges prebend to fit the mold in the shovelarea. No Tipspacer for the shovel. I made this ski for the third time, 1st with 2.5mm in tip, 2nd with 3mm and now 2.3mm.

after pressing for 14 hours @ 40 Degres Celsius I let them cool in the mold and removed them. Veneer looked great but the P-tex was hollow, on both skis, tip an tail. I could compress it approxmimately 1mm. Firts thought wasthe core wasn´t coorectly aligned with the edges. So I used my saw and cut right through that area. The edges were right where they were supposed to be...
Maybe not enogh resin? But the glass looks pretty full of resin, same the ptex.
After I made about 20 pairs this one is the first wich is completely f...ed up (besides the first ski). What bothers me most is that I have no idea why.

Does anyone have an idea?

Thanks,
Hannes

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vinman
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Re: Hollow P-Tex

Post by vinman » Mon Dec 02, 2019 7:19 am

That is almost always going to be a pressure issue. Not enough pressure in that area if the mold.
Fighting gravity on a daily basis
www.Whiteroomcustomskis.com

Hannes
Posts: 87
Joined: Wed Nov 09, 2011 2:20 am
Location: NRW, Germany

Re: Hollow P-Tex

Post by Hannes » Mon Dec 09, 2019 8:40 am

Hi Vinman, thanks for your reply.
At first I didn´t want to believe what you wrote so I kept searching and cut the skis open at a few more places and I also took a closer look at the suction-hose that led to the vacuumpump. It was clogged with a little piece of fleece. So I think thats the reason why there was not enough vacuum in the bag even though the pressure gauge told me so.
Now that I found the reason why things went wrong I am motivated again to make the next pair.

When I started building skis someone on the forum wrote someting about "obsession". True words....

Cheers
Hannes

24Dave
Posts: 105
Joined: Mon Oct 03, 2011 2:14 pm

Re: Hollow P-Tex

Post by 24Dave » Mon Dec 09, 2019 9:50 am

Hannes,
I had a similar issue when my vacuum hose partially collapsed since it was not able to withstand the heat in a curing oven.

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