Cheap ass HF 85W pistol with the blade tip. slide heat shrink down wire, push wires together and mesh strands, place iron under joint, pull trigger until solder flows from top of wires, about 5 seconds, release trigger, slide heat shrink over and hit with heat gun. 20W pencil is good for circuit boards no more. I use a little 2 aligator clip "helping hand" fixture to hold the wires together while I get solder tip under joint and feed solder from top, almost need 3 hands for it.