yes, K2 has used it in some form; since their beginning---however clear spruce species such as Sitka spruce are generally very expensive--probably since it's used in the Aviation world for things such wing spars and the like
I don't know about US, but in europe spruce is the cheapest wood around, still a pretty good option. I know several manufacturers using spruce, even unlaminated whole wood cores, mostly because of the price.
Thanks for the warning. I was thinking of routing a well in the unprofiled core and filling it with a flexible epoxy and mix of pheholic microballoons and microfibers to create sidewalls and tip spacers. Hopefully that won't create i'ts own problems.
This is the way i repaired the sidewall after damages - but it not very strong. I would recommend to use a different wood (like Ash) for the sidewalls.
