Ski Builders Forum

Thanks, Makes sense now so much to learn so little time,, so balance the carbon top sheet with a simular layer below. or ditch it all together, The edges are lower than the base and were affected by the grind the center was untouched, interesting how carbon can affect it so much.

Now I m Not sure why i would even rabbet the edge now, abs has a melting point of 221 *f At 180*f its probably formable enough and would push into the edge as it is softer than Ptex base.

thanks lex , big dog

Cheers
Jim

what you're saying is i could build something like a bataleon triple base by just adding carbon in certain areas?!
that would be awesome!

http://www.bataleon.com/en/tbt

Checkout the video above. I've thought about making a ski tip similar to the snow board one. The concave edge of the tip would be concave maybe 3-5cm from the start of the running length toward the toe binding and extend through the entire tip. But my idea has the ski base flat as usual.

Horizontal rocker??

I had the problem of concave bases for a while, I rebuilt my entire camber mold, reinforce my press... and still had slightly concave bases...
The last few pairs I used ways less resin and my bases are flat again !

I believe I used to put too much resin when wetting the base before the VDS/first layer of glass and with all the pressure on the edges (even with edge recess) the flow of resin when pressurized was not efficient enough, leaving too much resin in the middle of the base -> concave bases !

Ben, I hear you on the too much epoxy. Doesn't matter how much pressure, you can't squeeze it out. The first factory I worked at making wake/kite/skateboards in the mid 90's. We had one guy who did all the lay-ups, once he got fired or quit, my boss started doing the lay-ups & we shaved a pound off the wakeboards. One of the best ways is to put down some cardboard or paper, wetout the glass on that then put it onto the base/core. Laying down the glass on the base & then pouring epoxy down & you get issues. For me(on boards) if I pour the epoxy on when the glass is on the base/core, I had more epoxy on the base(more finishing, plus you lose base material), added weight & voids(epoxy rich areas).

Putting carbon stringers on the bottom to get a convex base. Just putting 1" stringer gets you just a little, probably around .5mm. Trying to get a bataleon amount would need more, but the tips of the core are thinner so it might do more....haven't tried it. The bataleon is shaped more like 3 surfaces were the carbon will be more of a curve. Haven't seen the bataleon for 2012 yet, they moved production to Elan from GST. Elan is going to be making skis with this tech so they gave Bataleon a deal they couldn't refuse...like royalties if they move production. Omatic did something kind of similar but more on the length of the board, however not one board ever made it to production....only salesman sample were made...too hard to finish the base.

I am living the same problem, like Ben said

in my case i am using hard transparent base 1.1 mm thick and i rechecked all my process before and all the boards before were perfectly flat, and with this base no... i dont know what to do more to avoid this problem...

If this is happening only with that base material it must be a shrinkage thing too. What is the new base spec?

Stan

Another though I just had would you be able to bring the press temp to a lower first stage cure point. Hold there for a while to get the epoxy set. Then ramp up to the final temp. That way the resin will have kicked at a lower temp and should hold the materials at that dimension where the expansion is not as exaggerated.

Yesterday i toke a board from the press and again concave, and then i start searching deeply the problem, and then i realize that the bottom blanket was broken on one wire and then as my molds and cassets are made of steal, it doesn't get get hot due to energy leaking to the press frame then i fix it and test the heat blanket, and now it makes heat for all over the heat blanket,.

conclusion, the top blanket was pushing all the concavity ...