The interior of the frame tube and exterior of the Mod 72 tube was given a good coat of ACF-50 and the Mod 72 tubing was inserted into the frame tube. I was able to hand press it in about an inch (2.5 cm) or so. From there a rubber mallet was used to tap the tubing in as far as possible. The last couple inches (5 cm) needed a block of 2x4 placed between the tube and the mallet to finally drive it home.