Very rough: Linear taper from front/ rear binding to zero at tip / tail = evenly distributed pressure along edge Stay thick longer = more pressure at tip/ tail Taper down faster=more pressure near foot. This is for a hard surface and a 'matched' stiffness. An overall softer ski will result in the re...

Glass will be something like 1:3 , maybe lower down to 1:2 Carbon is something like 1:6 ... 1:3 It is a bit tricky because the longitudinal stiffness of biax depends on how constrained it is. The more free it is to contract in transverse direction, the lower the longitudinal stiffness (So adding a 9...

What I read is that for high grip it is better to have a few high pressure points along the edge instead of an evenly distributed pressure . Makes sense to me, a few high pressure points to cut into the ice. But on my alpine carving snowboard I design with a very evenly distributed pressure, and I n...

Your first bullet is a bit confusing, but you definitely need titanal in both your too and bottom laminate. Otherwise your camber will change with temperature. Different thickness is fine, I prefer 0.6mm top and 0.4mm bottom. Bottom titanal I cut narrower to fit between the edges. That way you don't...

I'd like to add that from a mechanical point of view it is best to have the 45° layer facing the core. The biax layers have a lower apparent stiffness in the main direction of the core, which will result in less shear stress at the bonding interface between core and laminate and help with longevity...

Vacuum I built my first board (successfully!) on an MDF plate, bent it a bit to provide camber. Fastened it on top of a wooden bean to hold it in shape. Sealed the plate surface with epoxy(to hold the vacuum since it's porous). Made some ramps for the nose and tail that I placed on top of the plate....

With a long and gradual tip/ tail, you can just do a continuous core.

I put rub on wax on the base, except for the last few mm from the edge. I take most of the epoxy of with a scraper (home made one, about 100mm wide). The last bits come off in the base grind. The wax makes the epoxy come off easier, and I figure that epoxy would also fill the pores of a sintered bas...

A 2mm wood core will not conform to your mould if there is an abrupt transition to the tip curvature. It may appear so visually,, but conforming it to the tip curvature requires bending moment, and that bending requires some length to build up if you only have vacuum pressure. Not much, but at least...

Oh and taping the base should work. I recently glued a titanal top laminate back on a board under vacuum. I taped the base along the edge, and it came out clean. But I added filler to the resin for gluing, which will have helped.

Some resin is unavoidable, when applying vacuum the (low viscosity) air tends to flow out fastest(luckily) and replaced by resin. Next the excess resin flows out into your breather. If there is more than a film of resin on your base, then somehow.the base does not get pressed onto your mould. It can...

Considering how hairy it is, too little epoxy seems plausible. If the topsheet came off without force, you'd expect a smooth surface if enough epoxy was used.

I recently had a titanal sheet come off (should have respected storage time and condition). That left a perfectly smooth finish .

I did not mean to imply that mechanical properties go up with higher post cure temperature. I was comparing to no post cure at all, as I understand from RealMcCoy that he just did a room temperature cure. Regarding the Sicomin resin, I just checked the datasheet. Be careful with the interpretation o...

Your total fabric weight should be ok. But the spec is a bit vague. :-). Glass fibers come in different qualities and with different sizings(= surface finish) suitable for different resins. Epoxy is quite easy going in this, but the fabric is probably far from optimal. The floating of the fabric in ...

Ah yes because you mentioned cure maybe I focused a bit to much on that. If your fabric was also old and not stored dry (humidity), the fibre sizing may also be the culprit.
And as said it could simply be insufficient strength.