[Elecraft] quick (gooberheaded) solder question

[Don Wilhelm]

Steve,

With a temperature controlled soldering station, the wattage does not mean
as much as for a non-temperature controlled soldering iron.  The important
thing is that the soldering tip has sufficient heat mass for the junction to
be soldered at a temperature sufficient to flow the solder in a short time.
Your Weller should work just fine.

There is some judgement and a bit of technique to exercise in soldering.
You may want to practice a bit if your confidence level is not 'up to
snuff'.  The goal to shoot for is to be able to apply heat to the junction,
apply solder and have the solder joint completed within 2 to 3 seconds.  If
it takes longer than that, the iron is too COLD for that particular
junction.  Components with 'fat' leads or connections to a PC board ground
plane can be expected to take fall more in the long end of the range since
they will conduct heat away from the area to be soldered more quickly than a
small solder pad and a thin wire lead - so using a bit of informed judgement
is a good thing.

Components are usually designed to take high soldering temperatures for
short periods of time without damage.  If  the soldering dwell time is
excessive, component damage is more likely.  I normally use a temperature of
720 to 750 degrees F (380 - 400 deg C) depending on what I am soldering.  An
iron with a larger tip can operate at a lower temperature, but closely
spaced components require a small tip, again, some degree of judgement based
on your technique is required.

73,
Don W3FPR

----- Original Message ----- 

| I just got my KX-1 kit (#108) but I have a question before I proceed!
|
| My soldering station is a Weller and it's calibrated in Degrees.  The K2
| manual states 25-40 watt iron (with a tip of 370-430 deg C).  I'm assuming
| this will be also correct for the KX-1 though I couldn't find anything in
| the KX-1 manual that discussed solder temperature (I admit I may have
missed
| it!)  Since I'll be soldering ICs directly to the board, I thought I'd
write
| and ask the group about this before I go roasting all of my ICs due to too
| high temps or too-long soldering time.  So I guess my question is, what
| temperature corresponds to 25-40 watts, or is it simply the tip rating
| (i.e., I set my station to 400 deg C)?  Obviously the lower I set the
iron,
| the longer it will take to make the joint; but too high a temp will fry
| parts.
|
|