What are the differences between the various HPR body tube materials used by the most HPR manufacturers?
The most common one is that material used by Estes and later by other suppliers such as U.S. Rockets, LOC Precision, AeroTech, Launch Pad, etc. This material is a spiral wound virgin kraft tube. Virgin kraft is stiffer than recycled kraft and can much more easily withstand flight stresses at a given thickness than recycled tubes as commonly found in household goods. This material typically has an outer wrapper of “glassine” which makes the tube smooth and accepts paint more easily. It also covers up the thicker tube spirals of the underlayers and makes removing tube spirals with a couple applications of sanding sealer practical. Another common tube material is that used primarily by Public Missles. It is a spiral wound paper with phenolic resin impregnated into it. This has several advantages such as higher ultimate strength in aero-applications, more waterproof out of the box and being fairly stiff. However this material is also susceptible to cracking due to impacts and has been know
