With the spaghetti seal, I use 3M 847, same as the gearcases.
First clean with acetone.
I use a small brush, and apply it evenly across the mating surface. You don’t want too much that it will get into the passages. Push the spaghetti seal to outer edge of groove, before trimming, so that it cannot shrink.
Align crank case halves, drive in alignment pins, then torque bolts to spec.