Phenolic tubing is a resin impregnated, spiral wrapped, and heat cured tube. It is much stronger than cardboard tubing, with almost 5x the compression strength. It is also a very good base for rockets that will require the strengthening of fiberglass, Kevlar, carbon fiber, or similar materials. For this reason, we recommend phenolic as the appropriate tubing for rockets that are 6.0, 7.5, or 11.4" in diameter, or rockets that will require strengthening for the rigors of transonic or supersonic…