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Re-Press of skis

Posted: Sat Jan 07, 2012 11:14 am
by Jekul
I pressed a pair of powder skis last year with 8mm camber under foot and tip and tail rocker of ~20mm. I finished them out and skied them a couple of times and decided I would like to have ~60-80mm of rocker in the tip. So this summer/fall I built up new rocker profiles with my new desired shape.

Rather than make an entire new pair of skis and relagate my old skis to my learning wall, I wondered if I could heat them back up and change their shape. After doing some research I saw a few people on youtube (I know, not the most accurate source....) using heat guns to increase tip rocker.

Has anyone done this before? Anything I should be wary of?

I'm planning to basically repeat the first press process, including a 35min. soak at 160F and 40psi.

Posted: Sat Jan 07, 2012 1:30 pm
by skidesmond
Not sure that will work since the epoxy has cured by then. I've heated the ski to re-activate the epoxy a couple days after pressing and that works.

Posted: Sat Jan 07, 2012 5:37 pm
by MontuckyMadman
Do not use a heat gun. I have done this. It gets to hot to quick and will cause a topsheet and top fg layer delam. Repress yes, you will have to get to near 200f to really change the shape. Soak the skis for a while at temp like 45 min.
Tgr guys do the heat gun deal but if you have a press and heat no reason. You are damageing the epoxy by reheating it so be aware do not sell this and it could destroy itself but kinda unlikely.
This is from my personal experience.
i also would let the skis cool a bit under pressure rather than a hot pull from the press say to 140f or so.

Posted: Sun Jan 08, 2012 5:20 pm
by Jekul
So I tried the 160F method at 30 minutes with no change in camber. I let them sit in the press under pressure until they cooled back to 100F.

Montucky - I'll try your method later this week and report back. I'll also tried to capture some before/after pics to show what the results look like. Thanks for the recommendation.

Posted: Wed Jan 11, 2012 7:24 pm
by Jekul
Just an update or anyone following:

Put the skis in the press last night for 45 minutes at 195F. When I pulled the skis out only the end of the tips (final 4") of the skis started to take the shape of the mold. My plan for tomorrow is to increase the temperature a bit more (10 degrees) and press another time. My primary concern is that I start to approach the melting point of the base (yes, I've done that on a pair of skis), however that should be around 220-240F, so I belive at 205-210 I'll be OK.

Posted: Mon Jan 23, 2012 6:40 am
by Jekul
Thought I'd provide another update to those interested:

I took the next step up in temperature the other night. Ran the full press up to 220F (bottom blanket setup). I also decided to let them sit a little longer, so under T and P for >1 hour, then I turned the heat off and let it sit overnight.

I pulled them about the following morning and...no change from previous attempts.

Conclusion
Bad News: If I want more rocker in my tips and tails I have to make another pair of skis.

Good News: I get to make another pair of skis for myself!
Good News #2: The Epoxy/Hardener combination I'm working with is extremely solid.

Posted: Mon Jan 23, 2012 12:24 pm
by jono
I have repressed skis with success without a heated set up.
I've had a few pairs come out too stiff. For these I planed and sanded off the topsheet, top layers of carbon and glass down to the core+tip spacers. I sanded the cores down a bit and then replaced the carbon+glass+topsheet and repressed with the original mold.
I suspect that if you take off the top composite layers and then repress in a new mold with heat you'll be able to obtain a new camber/rocker profile.
Your profile might not be the same as your new mold because you will have a ski that fights between two camber profiles. This might also make your ski more lively.

Posted: Mon Jan 23, 2012 12:33 pm
by Jekul
Jono,

Thanks for the idea. Innovative but somewhat risky. Seems like I'd almost have the same amount of work as building a new ski, without getting the profile I'd want.

Rather than destroy a decent pair of skis I'll probably just make new.

Posted: Tue Jan 24, 2012 10:48 am
by jono
Making new skis is way more exciting!!!