I too encountered issues with the new, stiffer flex fletch vanes. I had to soak the bases in acetone or MEK for about 30-45 seconds using a small tin container (Copenhagen lid or altoid breath mint tins work great). After the soak I put the vane in the clamp and scrub with the green, rough side of a small piece of sponge I trimmed of a new kitchen dish sponge dabbed in the acetone or MEK. After the scrub I wipe it down with a clean cloth dabbed in acetone/MEK, then glue with solvent based glue like flex bond, fletch tite platinum or Saunders NPV. Ton of extra work, but my vanes are holding tight! Archery shop actually gave me a bunch of flex fletch because he was having too many issues on customer arrows. Said if I could make them stick I could have them.