Abstract: A cover plate extends over a solder reservoir and has a slot for a solder wave to extend up above the plate, a gas excluding oxygen is supplied under the cover plate and flows up through the slot on both sides of the solder wave to blanket the solder wave. It has been found that oxygen content on the surface of the solder and on the solder wave is reduced so that clean oxide free soldering occurs. The apparatus has a solder reservoir for holding solder with a solder nozzle projecting therefrom, a pump for forming a solder wave from the nozzle, a cover plate for covering at least a portion of the reservoir having a longitudinal slot for the solder wave to pass therethrough. Provision is made for supplying pressurized gas, which is oxygen free, to pass upwards through the slot on both sides of the solder wave to provide a gas blanket over the solder wave, and a conveyor conveys elements to be soldered to pass through the solder wave.