I pressed my first pair about a month ago, and tweaked different things for each ski. They both have the same core and sidecut profile, but I wanted to try a couple different things in the layup. They are a true 190cm ski with dimensions 128-103-118, a camber of 8mm, and the core is an array of 3/4" white ash and aspen. There is 3 strips of white ash, and 4 aspen with white ash running down the middle followed by aspen on either side, then white ash, then aspen. I was trying to imitate the stiffness of the Volkl Explosiv, just a little fatter. The rest of the materials were pretty standard-22 oz. fiberglass, VDS rubber, durasurf base and topsheet, and ash sidewalls.
The first ski I pressed, (on the left), had the core extend up into the tip and tail and then the tipspacer was cut out around it. This seems to be fine for the functionality, but I was using 1/8" ABS for the tipspacer and it turned out fairly difficult to try to sand down the ABS to match the tip and tail angle created from profiling with a planer. Subsequently, the mate where the ABS and core meet is slightly visible. I also tried to edge wrap the tip, but the pointy tip proved fairly difficult to work with. I was very pleased with the alignment of the ski as the core stayed perfectly in place. I liked that I left the graphics section without the red flannel to verify this. The die cut black rhino under the fiberglass and topsheet as well as the WEDELL graphic came out very clear.
The second ski I made, (Right), used the method of having squared off edges on the tip and tial section of the core blank, and then the whole tip and tail section is pre attached ABS. This seems to be what Kingswood does, and to model that I heated the ABS and formed it to the tip and tail sections of the mold to pre-form it.This created a very professional looking transition between the core and tipspacer. I also did away with trying to wrap that tight curve around the tip, and stopped the edges near the tip and tail like my Volkl Explosiv's.
Both skis had the bases held to the mold by double sided tape, and the excess material of the sidewalls was nailed to the mold after alignment. One thing I did not do that I wish I had is using the masonite board I bought as a top pressing layer. The firehose did imprint a little on the clear p-tex topsheet, so I need to use something smooth in between next time. I also thought the 1/8" ABS for tip/tail spacers was too thick, so I have since gotten 1/16".
In my measurement systems class, I am testing various deflection values, stress conditions, and vibration damping properties of my first skin against my Explosiv. We have a bunch of strain gages on both skis and are spending the last 3 weeks of class on this final project. I'll post anything I learn here once I am done, but for now here are some deflection pics. The first is a tip deflection test with 4.77kg on the tip, and the roller back 100cm from the weight. The second is with 22.7kg applied at CC.
I currently have a ski made from an all aspen core with white ash sidewalls in my press, so pictures of that will follow soon. --Geoff
