Ski Builders Forum

...don't let the water heat to anywhere near boiling. What started out safer than a pnuematic press would then become much more dangerous...

Very good point. Letting the water get anywhere near boiling (212F) would be nuts but a temp rage between 120-125F (home water heater range) seems like it would be OK -you just need to make sure you can actually control that.

not exactly sure why but i think the most common curing temp for ski/board building is 170-200 degrees.

Read the thread about the Q&A with Roy from QCM, i think in there he says why.

not exactly sure why but i think the most common curing temp for ski/board building is 170-200 degrees.

I'm OK with the 120 to 125F range because it's still better than where I'm at now (room temp in a basement).

Thanks for posting the pictures of your clamping press. It really is a simple design. I built a simlar press and it worked great.

I think i'm going to go this route. Looks simple and easy and a lot safer than applying pressure.

thinking about using tie down straps that cinch up instead of screws.
To keep it even more simple.

i like this a lot.

thanks for sharing.

I like where you were going on the heated water asspect of things. I took it one step further and inbetween my bottom mold ribs I have fastened 1/2 hose just below the mold surface and am running a automotive recirculating block heater and a pump. The block heater keeps it between 130-140F and its not presurized, it just flows to a sump area and is pumped back through the system. Still in the process of getting to finally do a full run (sick of trials), should only be a few weeks now. Will try to get pics and if anyone has any more ideas let me know...

I'm a newbie and a non-engineer who's never built a pair of skis, but this seems to make a lot of sense to me. It seems like you could heat the water up just before you put the boards in the press, cover the whole thing up with a sleeping bag or electric blanket or whatever, and have a pretty low cost, simple way to introduce some heat to the pressing process.

I love all the different solutions people come up with. Thanks!

I really like this method too, I use a very similar clamp press to make longboard skateboards and am able to put very dramatic bends in the deck (drop deck speed boards), much more than I can get with a vac bag.

I have never seen a blatter used for skateboards in a manual press, definitely a great idea to distribute pressure.

I am thinking of trying this route for skis for the sake of simplicity and a smaller / lighter press. Plus I like the idea that sometime in the future, the moulds could be used in a proper pneumatic press.

Anyway to my question: Say I did decide to spring for a quality heat blanket and heated from the bottom. from peoples experience, what is the temperature gradient like across the skis and to the blatter? Basically could you avoid bloiling the watter and still get a good amout of heat in the the ski for curring?

maybe some insulation would be required. I dont know.

I´ve made a mold and using water in my hose. So far so good...

Here´s the set up

Base
Rubberstripes
Glassfiber 22 oz triax
Maplecore laminated (2mm - 10mm - 2mm)
Glassfiber 22 oz triax
Graphicdesign on ricepaper
Top sheet

Now to the problems. I made a pair of skiis, one at a time. What happens is that the core cracks longside where the steeledge is. I´ve made the core around 10 mm wider then the base. Why is the core cracking? Too much pressure?

Next problem: My skiis are way to soft! What can I do? Put more fiberglass under the core? Make the core thicker? Is it good making the core thicker than 2 mm? Put some other wood in and laminate with the maple? What is good to make it stiffer? Did I use to much pressure so that the epoxi ran out and thats why the ski so soft? There was plenty of epoxi that ran out of th mold when pressing.


I can´t really tell how much pressure i put on my skiis as I´m using a waterhose. The hose is hard as a rock when I have maximum pressure.

linuslimpan wrote:I´ve made a mold and using water in my hose. So far so good...

Here´s the set up

Base
Rubberstripes
Glassfiber 22 oz triax
Maplecore laminated (2mm - 10mm - 2mm)
Glassfiber 22 oz triax
Graphicdesign on ricepaper
Top sheet

Now to the problems. I made a pair of skiis, one at a time. What happens is that the core cracks longside where the steeledge is. I´ve made the core around 10 mm wider then the base. Why is the core cracking? Too much pressure?

Next problem: My skiis are way to soft! What can I do? Put more fiberglass under the core? Make the core thicker? Is it good making the core thicker than 2 mm? Put some other wood in and laminate with the maple? What is good to make it stiffer? Did I use to much pressure so that the epoxi ran out and thats why the ski so soft? There was plenty of epoxi that ran out of th mold when pressing.

Not sure why your core is cracking but I've seen them warp when you have overlap. To avoid this I've put scrap edge or something of the same thickness outside my edge to give the core overlap/overhang something to push on.

Your skis are too soft because your core is too thin. How long are they?

I would say make them 12mm underfoot. 2mm is a soft tip, but works, 3mm is a much stiffer tip.

If 12mm is still to soft try making a platform - an are where it stays at 12mm rather than just peaking.

I have a platform of around 25-30 cm. Skiis are 176 cm

Ok, I´ll try to put some spare basematerial at the side of the base and make the core 3mm -12 - 3 mm.

Do you think I should put some more glassfiber in aswell? My skiis are very light too. Only 1.2 kg! So I have some place left talking of weight...

Do anybody have a illustrator file of the core in profile. Don´t really know how the core should look like in profile. Or a snowcad-X file?

the profile is really up to you. here are some examples to get started with
http://www.skibuilders.com/howto/skicon/profiling.shtml

we don't do linear profiles on our cores. we have a 12mm section under boot.

I am confused as to why the water is in there?

I could see if you filled it entirely with water, and no air... but why only half fill it with water? Seems completely pointless to me... Air is compressible, water is incompressible. Either go all air, or all water.

Ok I read a little more and see that you're not actually doing half full, but entirely water.

So you're really not getting any more pressure using the water in the hose, it just helps even out the pressure. Either way you are limited with how much force the bolts can take, adding the hose does not add pressure, only evens it out.

This looks like a pretty interesting design, does anybody else have any experience with this type of press? Do you know what type of pressure it's capable of generating?

This would be a great temporary solution for my buddy and I while we try to locate space for a steel press in the future.

Thanks for any input!