The easiest way I’ve found to attach boning tips is as follows….
Using a pair of needle-nose pliers crimp the sides of the tip inward BEFORE putting the tip on the piece of cut spiral steel boning.
After crimping the sides in quite often a little pucker or bump is created in the top of the tip… to get rid of this hold the sides of the tip (so they dont spread back any wider) and then use the needle-nose to crimp in the little pucker that formed at the top of the tip…
The trick is to have the tip pre-crimped just a little smaller than the width of the boning. When you slide the boning into the tip it will open just enough to allow the boning to slide in, but will still grip tightly around it.
Once the tip is on the boning and does not slide or move you can dip the ends into Tipping Fluid to form a more permanent bond. If you choose to do this, you should let the ends dry for about an hour (more or less depending on humidity, etc) before inserting them into the bone casings.
….That’s the method we’ve always used. Hope it helps!