[Elecraft] Solder Station

[Ron D'Eau Claire]

Given the opportunity to use either a 20W or a 40W heat range, I'd use
the 
40W because it should allow you to get in and out more quickly.

Tom Hammond   N0SS

----------------------------

I'd TRY the 20 watt setting and see, Woody. The amount of heat an iron
will generate for a given "wattage" will depend upon a lot of things
including the thermal efficiency of the element and the heat
transferring connections in the iron, size of the tip, your habits
regarding wiping/cleaning the tip, etc. 

I built my K2 (and just about everything else including SMC stuff) using
a 20 watt grounded-tip soldering iron that is NOT temperature
controlled. Only a few connections (e.g. the mic connector on the K2)
needed more heat, and I have a small gun for that work. As Tom says, it
is very important not to use an excessive "dwell" time on a joint. That
will cause you to burn a trace loose from the board no matter how small
of an iron you use. The other extreme is that you have such a hot iron
that you burn the board before the solder has time to absorb enough heat
to melt and flow properly. 

I have a 40 watt "desoldering" iron. I must be very careful with that. A
40 watt tip allowed to accumulate too much heat can easily lift a trace.


I use a conical tip almost exclusively. I can get into tight places
easily with it (no problem with 'burnt' relay cases, etc.). I count on
the heat transfer being via the small drop of solder that melts off of
the end of my solder wire to connect the tip to the joint, not on a
large metal-to-metal surface areas touching each other. I apply the
soldering iron tip and the end of the solder to the joint
simultaneously. Immediately a small amount of solder melts to connect
the tip to the joint, and then I feed in enough additional solder for it
to flow through the joint properly. Then I'm off. 

Dwell times on a pad on a K2 board using the 20-watt iron were typically
2 or 3 seconds for me.

Ron AC7AC
K2 # 1289