"krem" wrote in message
s.com...
Hello, I'm looking for some advice on what to look for in a soldering
iron.
I'm going to mainly be using it for through hole components but will have
the occasional SMD part to place. Before today I had two irons, one
15watt
i used for smaller components and a larger 45 watt I used for larger
tasks.
The 15watt died on me with a big flash today, not really sure what
happened
but the set screw broke about two months ago letting the heating assembly
rotate in the shaft of the iron so my guess is it shorted at some point.
I
know not really the smartest of things to keep using but it seemed to work
well. anyways the 15 watt always seemed a bit low to me, at times not
getting the components up to soldering temperatures just over heating
them.
I feel like I should get something around 25 watts but again not really
sure. Not to mention a brand if it is felt there is one better than
another. I know weller has excellent stations as well as irons but I'm
looking to keep this fairly reasonable with pricing. Any thoughts or
suggestions are welcome, I'm always looking to broaden my knowledge base.

On a side note any recomendations on a de-soldering method? I've never
used
any tools other than the iron which has lead to some ugly jobs.


While a Weller or other temperature-controlled solder station is going to be
the best, I've had good results with one of Antex's small pencil irons:
http://www.antex.co.uk/ You can get tips in many different shapes and sizes.
The price is also very very low; under $30 for the iron and about $5 for
each tip. I got mine from HMC electronics: http://www.hmcelectronics.com
(right now they have a stupid thing preventing browsers other than Internet
Explorer from working, switching user agents doesn't fix it)

As for desoldering: I have no patience with solder-suckers and the
huge-solder-blob method, and I only use solder wick to clean up
surface-mount solder bridges. My method of choice is to mount a heat gun
somehow over the circuit board, and run it just until the solder melts. Any
component can be removed this way; I've used it up to PQFP-208. You can
remove a large QFP in under a minute with this method. No fiddling around
with solder wick, thin steel wire, or anything like that. You need to take
care to mask off plastic parts and anything you don't want to desolder,
usually with a couple layers of aluminum foil. Also take care to shut down
the heat gun as soon as the solder melts; this ensures that the internal
chip temperature doesn't rise too high. Since you are heating the pins
quickly, there shouldn't be enough time for the internal die to exceed 430F.
If you are scared of overheating the chip, you could put a small ceramic
tile or something on top of the chip; I've never destroyed a chip this way,
though it is possible if you leave the heat gun on too long. Be careful of
any nearby components like chip capacitors; they'll be loose too.

To desolder two-terminal surface mount chip components, the best way is to
add a little solder to one side so you have a larger bead there. Then you go
to the other side and melt it; since the larger bead of solder holds heat,
it will still be melted if you work fast enough. Then you can quickly remove
the component with tweezers or just slide it off into the solder mask with
the tip of the iron.

So there's your complete soldering and desoldering solution, for about $50.
Keep that larger soldering iron around, I still use one for soldering larger
surface-mount chips quickly.