Abstract: A method and apparatus for vapor conservation and control for use with vapor phase soldering, degreasing, or similar systems having a tank into which work is introduced and removed. The air present above the processing vapor zone is drawn from the processing tank and cooled to condense the vapor, and the remaining air is then returned to the tank above the area of withdrawal. A negative pressure is preferably created at the tank entrance such that air flow is into the tank to prevent emission of vapor and pollutants from the tank into the atmosphere.

Abstract: The method of solder leveling comprising maintaining a zone of hot saturated inert vapor at substantially the temperature of molten solder above a molten bath of solder, moving the part to be treated through the vapor at a rate such that it will become uniformly heated to substantially the temperature of the molten solder prior to immersion therein, immersing the part in the molten solder, withdrawing the part from the molten solder through the saturated vapor to the ambient atmosphere and, while withdrawing the part, projecting streams of hot, high density fluid on the surfaces of the part in directions opposite to the direction of withdrawal to sweep the surfaces of the excess solder.