It seems like the majority of my build effort on mid-power rockets is spent working on trying to make body tube spirals disappear in order to strive towards attaining an excellent smooth finish. I have watched every video and read every thread on the subject and have tried many techniques but still at times get less than hoped for results. My thought is that if a kit manufacturer could come up with a way to construct paper tubes with the spirals already filled and the tubes ready for paint I would most likely be a buyer. Of course, the price of the kit would go up but would it exceed my current cost in filler, primer, sandpaper, time and periodic disappointment?