Cap ski made with press???

[telehead]

Been trying to build a cap ski with my press, haven't had the best of luck. I first tried with fire hose only (no cat track) and 1/4" #40 rubber, with a 25 degree side bevel. I only got the topsheet to go about half way down the sidewalls. I then got some discharge hose that was much more flexable, increased the sidewall bevel to 45 degree, and got the topsheet to go all the way down.However, it seams the topsheet trapped epoxy between the aluminun cassette and the sidewall/edge. I trimmed the core about 2mm each side narrower than the base thinking the FG/resin/topsheet would fill the gap. Maybe the core needs to be the same size as the base with the edges??? How about vacuum bagging with the press, could i then go back to the 25 degree sidewall?? Any thoughts would be great. Thanks alot...KT

[skidesmond]

I think it this has been tried.... I haven't tried it however. I was thinking the same as you, the core s/b the same size or smaller than the base. When you did the layup did you wrap the FG, etc over the sides?

[telehead]

Hey skidsmond, yea, did the same layup, base VDS /FG/ core/ FG/ Pbt topsheet. My thought was that the upper and lower FG layers would come together and make a nice "Box" . It seams that when the hose pushed the topsheet material down it sealed onto the alumunun cassett and trapped resin between the core and edge. If you look at the side of the (ski) sample it looks like there is a 2mm sidewall, which is the resin FG??? It also looks like there is alot of resin in the (section view) of the cross section that I cut. Make sense?? KT

[skidesmond]

Do you have pics?

[twizzstyle]

How about vacuum bagging with the press, could i then go back to the 25 degree sidewall?? Any thoughts would be great. Thanks alot...KT

I tried this exact thing last year on these skis:



I did a 45 deg sidewall, and the core was cut to the exact same size/shape as the base (without edges). On the first ski I laid up, the hose ended up clamping off the vacuum hoses (this was before I used a cattrack), and so it lost vacuum. I didn't realize this until I pulled the ski from the press, the top sheet only wrapped about 1/2 way down.

The second ski I made provisions to prevent the vacuum hose from being clamped, and it held vacuum the entire time and actually worked pretty great. Unfortunately I don't have any pictures of how the sidewalls turned out. It's not going to be a perfect cap like you'd get from a machined top-mold, but it's not so bad.

[danishstock]

I made these skis as a cap design in a vacuum press:
http://picasaweb.google.com/danishstock ... directlink

The cores and bases are identical width so the edges sit out proud providing a platform for the sandwiched glass and the top layer of glass to seal. All that glass and epoxy filling the corner between the sidewall and the edge provides excellent support for the edge. The vac bag actually became the form defining the fillet in that corner.

I found that the bevel angle is less important than the radius of transition from the top to side. You are asking thick fiberglass (22 oz) to bend around a corner, so the larger the radius the better. A 45 degree angle does also help because it asks that glass to bend less. So that my $0.2 - 45 bevel with a real soft roundover so that glass will lay over it easily.

I've been skiing that pair hard for three seasons with no problems. They even took me the 15 miles in to Katahdin in Baxter State Park.