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cores too thin...dang

Posted: Sun Oct 21, 2007 5:27 pm
by o2bjedi
So I was planing my core blanks out and somehow I ended up 1-2mm too thin. they turned out to be about 8-9mm at center instead of 10-11 like I had hoped. The cores are maple so at least it is a strong woodand sturdy platform for the binding screws. Should I add another layer of glass on top/thicker glass? I know Plywood mentioned he added a sheet of veneer over his core. Veneer is fairly thin though.
It isn't a huge problem, but now my skis probably won't be as stiff/strong as I hoped. Hopefully they won't be too soft.
Any tips?

Re: cores too thin...dang

Posted: Sun Oct 21, 2007 10:16 pm
by plywood
8-9 sounds fairly thin... and you already got what i`d recommend ;)

take it as a chance! i`d glue some veneer on it. take 2 sheets of 1mm veneer and glue the core in between, but do this in your mold. and what you`ll get is a sweet core that has the thickness you wanted. i think this would be the easiest solution...because 8mm is really thin, you had to apply more glas and everything gets heavier...but still soft.

Posted: Mon Oct 22, 2007 3:02 pm
by o2bjedi
Hey thanks for the help Plywood! Should I glue the veneer onto the core during lamination or before? Probably use wood glue other than lamination?

Posted: Mon Oct 22, 2007 11:02 pm
by plywood
well...it`d be possible to do it during layup. but i`d recommend you to glue it before layup. i always do it like this.

it`s a little extra work - in my case i only can press one ski/core at the time, so i`m pressing 4times for a pair of skis. and i inflate my hose with a bicycle pump by hand.

the advantage of doing it seperately are following: you can align veneer and core pretty accurate and you can take all the time you need to do this. this sometimes is a bit a fight because the cores "fight" against getting bent, so aligning could be a problem. after you pressed the whole core you get a "prebent" core - the core is already in shape of the camber/tip and tail stuff. and such a core is really a joy to work with, during layup: alignement is much much easier because you just can plop the core onto the layup and it will completely follow your mold - the tip and tails won`t stick up and lift the core away from layup anymore. it`s easier to keep the core in place.

theoretically you could do everything during layup...but i woudln`t recommend it. i`d fear that the core would shift too much between the veneers if everything is soaked with epoxy and alignment would be much more difficult i suppose.

about the glue...buh, i don`t care. i glue everything with epoxy. i never tried a different glue, neither on my skateboards nor on the skis...

Posted: Wed Jan 09, 2008 5:20 pm
by hadley
This results in the core extending out above and below the sidewalls. Is that a concern for wicking water and delamination. It must be a beautiful ski...

Posted: Wed Jan 09, 2008 9:36 pm
by littleKam
so plywood, you always use veneers as part of your cores? sounds like a cool idea about prebending the wood core. I had a huge problem today while doing a layup with my stiff core not wanting to lay down into the mold too well. I ended up having to karate kick my mold into the press. :?

Posted: Wed Jan 09, 2008 10:45 pm
by davide
littleKam wrote:...sounds like a cool idea about prebending the wood core. I had a huge problem today while doing a layup with my stiff core not wanting to lay down into the mold too well. I ended up having to karate kick my mold into the press. :?
Pre-bening the cores makes pressing much easier.
Now I have a nice polistirene box with an electric water heater inside.
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