I’ve used insert iron for several years with no problems. I don’t prep my shafts or inserts at all. I just put a point on the insert, put a generous amount of insert iron on the insert, twist the insert into the shaft, and then wipe off the excess. I allow it to dry for 24 hours. I check the shaft as it is drying, because sometimes the insert iron bubbles out of the end of the insert, and I scrape it off with my thumbnail before it gets too hard. About once a month, I clamp all my arrow points in a vise and give them a twist. Sometimes one will break free and I reglue it. Other times, I will accidently shoot the arrow into something hard and the shock will cause the insert to break free. When I get home, I reglue those. I’ve never lost an insert in a target since I’ve started using insert iron, taking those precautions.