I make a gadget for use in a swimming pool. It's essentially an LED clock. The display units are always failing at the pin connections to the solder pads on the pcb. It looks to me as though the pins are some sort of plated steel, and they rust downward from the end, and eventually this rust interferes with the solder joint. These units are a 3" 7-segment thing.
Pools use chlorine as a disinfectant, and ordinary steel does rust very quickly in that atmosphere.
I could solder them up and smother tem with some sort of goo, but if that did not work I'd have to get rid of said goo before fixing them again.
Any suggestions?