Possible Clues:

• Occasionally tries twine making lace again
• Bond goes on about action to make things secure again
• One leaving service -- though not with Sappers latterly -- is to join up again
• Fix, as some neckwear
• Fix a loose shoelace, e.g
• Fasten again, as sneakers
• It's about getting it back to Spain in knot again
• Fix a stubborn shoelace
• Fix some loose laces
• Fix a half hitch