This comment causes me to ask for a clarification ............
"Thank you for the heads up. I will test my Weller ( a 51 if memory serves – or fails) tomorrow. If it fails, I will continue to use for general soldering – ie working on turnouts and general wiring, but will have to find a substitute for decoder work.
Very interesting topic. Sounds like the issue is only when soldering the decoders. Is the "leaking voltage" not harming an engine on the track when soldering feeders?