Windings around an Iron Core

Kits Home Projects
1

I’m working on the K7102 (the metal detector). I’m stuck on the coil part.
Few questions.

  1. Is it OK to wrap the core with one layer of double-sided tape?
  2. I’m having trouble fitting and helding down 120 turns of wire around the core. Is it OK to have one turn of wire on top of another OR do all the turns must touch the core?
  3. For the kit to work, does the number of turns for each winding need to exactly what’s written in the instructions?

Thank you

2

1: OK
2: OK to have turns on top of each other.
3. Give or take a turn.