The boards we use may be new, old or home made and have varying degrees of oxidization.
thats why you want to make sure of two things :
1) Give the flux time to do its work ! That means the CORRECT setting so you don't evaporate it or carbonize it too quickly.much too hot and you end up with black sticky goop that actually prohibits good flowing. Too hot and it spatters allover the place.
2) use the correct type of flux. If you are soldering older parts with oxidation go for an RMA style or even an RA flux. Rma = rosin, mildly activated. Ra = rosin activated. That is really agressive flux.
It is important to clean up rma and ra type fluxes as they can be conductive in the 100 kilohm range, especially if you have been cooking them for long and they turned black. Iospropyl alcohol or real fluxoff ( chemtronics is the absolute king here, both for fluxoff and solderwick) works best.
Components used in a typical project we might work on can vary greatly in size etc. All these things make it difficult to set an exact temperature on your iron,
this is totally false !
The size of an object has NOTHING to to with temperature ! It is all about thermal mass. You can fry a mosquito with a match just as you can fry an elephant with a match, it will just take longer... Because your match has too little thermal capacity.
Use the correct tip (not a skinny point, those are for tqfp pins ) preferrably a short chisel or 'screwdriver tip' and have an iron with some 'kick' minimum 80 watst with a heavy supply and fast reacting control loop.
Chisel tips have the advantage that you can use them broadside or thickness wise.... Use the wide side for big objects , rotate 90 degrees for skinny stuff.
wears out the tip faster.
temperature does not wear out the tip faster. ( unless the plating peels off but then the tip was crap to begin with )
The tip wears out because part of the iron dissolves in the solder ( it must ! Otherwise the solder joint does not work ! ) the higher the tin concentration the more iron dissolves. That is why we have so called ' lead free compatible' tips. The difference sits in the thickness of the iron plating. A solder tip is a solid copper slug ( for good heat transfer ) plated in iron ( for solderability ) and coated with chrome where no solder is allowed to go. Once the iron gone the tip is shot...
The proper way to treat the tip is to:
- clean it off on a damp spunge ( not soaking wet ! Otherwise you have thermal shock ) swiftly to remove as much excess tin as possible and put the iron its holder. The fewer tin the less plating will dissolve ( it's a self terminating process )
- when taking up the iron , add some fresh solder , wipe off , add some more fresh solder and use this last blob to male the joint. Never ever solder 'dry'. ( i explained that before )
- do not use any abrasive stuff like knives , files or whatever in an attempt to clean the tip.
Even though those copper curls work well , they are not so good for the tip and should be used sparingly. Best is the tip cleaning pellets sold by kester , multicore , weller and others. This holds an agressive flux and a hard solder alloy. It cleans the tip thoroughly, poke the tip in the tablet and spin it around a couple of times, wipe off to remove agressive flux , apply fresh solder, wipe off again and put iron in holder.
If one runs into a problem, turning up the heat might help out...
cranking up the heat is NOT the correct solution. Check if you are using the right flux and a correctly sized tip.
There is a reason that there are tens of fluxes out there. Learn what should be used when and simply keep a few rolls of solder at hand. I got 4 or 5 rolls of solder. One medium thickness RA style flux 63/37, 3 thickness water soluble 63/37 and one fine rma.
In other words, not your typical rough and tumble hobbyist situation.
just because we are hobbyists is NOT an excuse to abandon strife for perfection. Just do it right.
It doesn't cost any extra money. A roll of solder cost you 15$ and lasts a long time. A good quality tip costs 5$ and , if properly treated, will last 5 or more years in hobby setting. So you actually save money in the long run.
I have several tips that are 7 or more years and they are powered up at least 8 hours a week.