4130 tube preparation for primer

The most important thing before priming the surface of 4130 is to remove any oil (commonly with acetone), make it clean, and to run over the surface with some fine grit aluminum oxide if there are any surface contaminants such as rust or other. Bead blasting can be used for thin wall tubing but with the Sonerai fuselage it is not recommended to use sandblasting because it takes too much off the surface of the metal and some consider it to reduce the structural integrity of the 4130 tubing.