[Elecraft] Solder....again.....

Wed Aug 27 20:37:02 2003

The temperature-controlled soldering stations run from 50 to 80 watts,
typically, which would cause a disaster on a typical PC board if they
weren't temperature controlled.=20

A simple 25 watt iron CAN do a wonderful job. I've used one as well as a
simple "port-a-sol" butane powered iron when I worked out of a back pack
fixing pc boards on shipboard electronic systems. You have to be smart =
about
"managing" the tip temperature though. For example, a 25 watt iron kept =
in
one of the popular 'spring holders' will either have tip that is too =
cool,
if the tip is touching the spring, or a tip that is too hot if the shaft =
is
the only part touching the metal spring.=20

But, overall, you should be seeing very good joints with a simple 25 =
watt
iron.

I would suspect that you are not holding the iron on the joint long =
enough
or not getting enough rosin/solder mix on the joint when it is hot. Big
blobby joints are often the result of adding dabs of solder to a =
too-cool
joint. =20

A good trick I've shown others who have trouble getting good solder flow =
is
to place your solder up against the lead and pad, then touch the solder, =
not
the lead/pad, with the iron. The iron should come in contact with about =
1 or
2 mm of solder, depending upon the diameter of the solder and the size =
of
the pad.

The solder melts allowing your iron to move against the lead/pad in the
puddle of molten solder. If you put the iron against the right amount, =
you
won't need to 'feed' any more into the joint. After holding the iron on =
the
molten joint for about 2 seconds, you should see the solder has flowed =
all
around the pad and lead. It's time to remove the iron.

One thing about small irons is that you must allow time for the tip
temperature to recover. Usually that's no problem. But if you're trying =
to
solder a bunch of leads one right after the other, you can strip the =
small
tip of its heat. If you use the touch-the-solder technique while holding =
it
against the joint and the solder doesn't melt immediately, you iron is =
too
cool.

That's the trick of a non-temperature-controlled iron... learning to
smell/feel the tip temperature. And it's why a TC station is usually =
worth
the money. Shoot, you can get really good ones, like the Hakko Tom =
mentioned
a couple of days ago here, for well under $100.=20

That should save you from discovering what happens when the iron is too =
hot:
the PC board solder pad pulls loose from the board.=20

Ron AC7AC

-----Original Message-----
From: [email protected] =
[mailto:[email protected]]
On Behalf Of Charles M Jenkins
Sent: Wednesday, August 27, 2003 5:08 PM
To: [email protected]
Subject: Re: [Elecraft] Solder....again.....

I've been just reading the mail because I don't actually have an =
Elecraft
kit yet. I got an inexpensive little Vectronics kit (not their soldering
course) to practice on as I haven't built anything with a circuit board
since the Heathkit HW 22A. My soldering looks bad, more of a glob, maybe =
not
properly adhered. I don't want to get a TC soldering station unless and
until I'm really going forward with building a big kit.

My question is: I have a 25 watt soldering iron. Is that too little? The
circuit board and components seem awfully small. Nobody every seems to
mention actual iron wattages.

                                                           Thank you,

                                                           Charles =
Jenkins
(Jinx  K7QVC)