Gabby: Trying to avoid accusations of plowing new ground eh?
Inert soldering: R Curthers et al, "Optimizing A No-Clean Circuit Board Process Using Nitrogen Inerting In A Conventional Wave Solder Machine," NEPCON West 1991 T Walsh, "The benefits Of Establishing A No-Clean Wave Solder System In Reducing Soldering Defects," NEPCON West 1991 G Schouten, "Benefits Of Inert Gas Soldering In Reducing Soldering Defects," NEPCON West 1991 H Hartmann, "Nitrogen Atmosphere Soldering," Circuits Assembly 2 (1), 60-66, 1991
SEHO was the first company to produce machines with nitrogen inerting. Now, all machine suppliers do. Check with machine suppliers. Also, check with inert gas suppliers. Some of them talk about retrofitting older machines.