The bottom of the metal canister is cut of, to allow a visual observation of the amount of paint remaining. It also provides a safety shield in the event the siphon bleed becomes clogged or if the siphon pressure valve is in the wrong position. Epoxy paints are sprayed with siphon feed at 5 to 8 psi & 20 cf/m of air. A GLASS JAR WILL EXPLODE IF IT IS USED WITH PRESSURE FEED OR IF THE SIPHON BLEED BECOMES CLOGGED! This has NEVER happened in 28 years of use, because the spray gun is always carefully cleaned & inspected after each use.
