Ski Builders Forum

Tried pressing two skis in the same cassette, close to each other (1/4", or so). When they came out, the cores/sidewalls of each were misaligned from the edge by about 4mm (i.e., each was pushed away from the center line).

Anyone seen this? The only explanation i can think of is that the epoxy expanded and "pushed" away the cores while keeping the base and topsheet perfectly in position, but this seems so unlikely i jsut can;t grip it. Epoxy doesn;t expand, does it? i thought it shrunk very slightly during setting.

Only other explanation is that i screwed up when I layed down the cores. That can;t possibly be it.

Did you cut a groove on the sidewalls to account for the edge teeth thickness? This will help keep the core centered a little bit.

A lot of people (including us) have started using pegs to place the core on the base. We drill two holes in the core, them make two dowels just the right length to match the thickness of the core there. We super glue those pegs to the base so that you can slip the core over them and the core won't move during pressing.

The only problem is you have to cut two holes in your bottom layer of fiberglass to go around the pegs, but that's a small price to pay for no worries about core shift.

Yes, it woudl have been useful if i had mentioned that. I'm using two pegs per ski, 3/8" by about 6mm.

The only thing i could think of is that either the epoxy dissolved the superglue (hasn;t happened before) or i somehow knocked both pegs loose, on each ski, by the exact same distance, which seems unlikely.

Jsut wondering if anyone else has had this happen...

I've had core shifting problems before but it was because I didn't secure the core in place. But sounds like you did that. Are you pressing with a pneumatic press w/ a cat track? I was thinking that maybe w/o a cat track the hoses could possibly push the layup apart, if the hoses are not inflated directly over the center of each ski.... Just a w.a.g., maybe the dowels broke but then you'd think the FG would have slid along with the core.....

Are there any small indentations from where the dowels were placed to indicate that they could have moved?

Well, the inserts are off, which can only mean the dowls shifted. I msut have broken them free., but wierd how symmetrical it is. Or I f*&$#d up.

Time to try again and see if i can get a repeat.

Thanks!