This graft is a great way to propagate the tree altho basic electrical tape sticks to itself works well. Wrapping the scions is good as it keeps them from drying out before the graft "takes". I like to use heavy rubber bands around the tree trunk to squeeze the the scions then tape it up. I also use melted Pine sap and bees wax or Elmer's wood glue to cover the open cut and any place where rain water might get thru to interfere with the Cambian matchup.
Al Brown
All The Best