Body help/advice needed

Ive tacked it about every 2 inches then I was trying to run beads between the tacks. I tried to just tack in progression from one to another but even then it will burn thru. I will let the tack cool some before tacking on the next one but I have to be very careful and slow. My concern is that just tacking will it penetrate good enough.
Rod

Tack every 2 inches next to the cold one instead of next to the one that still warm. Sometimes little more heat and wire less trigger is what gets it done. Also, the distance your tip is from the work can make a difference as too how much heat your putting in. Experimenation and practice like said.