I've heard that teflon tape used to seal waterpipes works for testing, but I haven't tried it yet. For final installation, I use the same hot melt glue used for aluminum inserts. I put a dab on the threads of the weights and on the sides of the weights and inserts. Then if you want to take it apart, you just dip the arrow tip into boiling water for 10-20 seconds. In the past, I've used the same thing for testing, but with just a small dab of hot melt to hold things together. That works well too, but probably not as fast to change things as teflon tape would be.