60/40 typically melts at 188°C, use 145°C and that'll help.
However, I suspect your biggest problem is simply lack of heat or sustained heat.
Nickel silver is a very good conductor of heat and will sap the heat away from the iron very quickly, that's why once you have the solder flowing it'll zap down a joint in a flash.
Lots of folks get by with a 50W iron, I never could and up rated to 80W and solder pretty much everything with it set to 400°C, get in and out fast. Though to be fair, nearly all of my work now, except detail work, is done with a micro flame.
The only down side is super heated flux which spatters and is a bit of a devil to clean afterward.
I use safety flux from Building O gauge on line Building O Gauge Online - Soldering and apply with a small pint brush.
Just about every reply you get will be different here, all good and well and I went through the exact same process a few years back; the trick is to try a few and find one that works best for you, but I do think your iron is going to be your main culprit.
As a quick test, buy a small cheap micro flame, waft it over a test piece and see if the solder then runs okay, if it does, then it's a lack of heat issue, if not it's your flux or solder.
60/40 typically melts at 188°C, use 145°C and that'll help.
However, I suspect your biggest problem is simply lack of heat or sustained heat.
Nickel silver is a very good conductor of heat and will sap the heat away from the iron very quickly, that's why once you have the solder flowing it'll zap down a joint in a flash.
Lots of folks get by with a 50W iron, I never could and up rated to 80W and solder pretty much everything with it set to 400°C, get in and out fast. Though to be fair, nearly all of my work now, except detail work, is done with a micro flame.
The only down side is super heated flux which spatters and is a bit of a devil to clean afterward.
I use safety flux from Building O gauge on line Building O Gauge Online - Soldering and apply with a small pint brush.
Just about every reply you get will be different here, all good and well and I went through the exact same process a few years back; the trick is to try a few and find one that works best for you, but I do think your iron is going to be your main culprit.
As a quick test, buy a small cheap micro flame, waft it over a test piece and see if the solder then runs okay, if it does, then it's a lack of heat issue, if not it's your flux or solder.