Thanks all for your tips.
From what I got, my prox dure should not be:
- Touch the hot iron to the solder wire
- Bring hot iron with solder dab to the board and touch the parts to be soldered
I am heating the iron enough if enough is 2-3 minutes.
I did buy Flux that comes in a plastic container. But I don't use it except when I start the job when I touch the hot iron tip to a dab of it. The reason was that my solder says it has Flux on it already.
Here are the pics of my iron and solder.
Ok - the solder is proper - 60/40 or 63/37 is what you should use (lead-free solder needs a higher temperature, plus it can be tempermental to use - also, never mix leaded and unleaded solders when soldering).
That iron looks - well - large. For those kind of non-temp controlled irons, you want at max maybe 25 or 30 watts; ideally a 15 watt iron would be fine.
You definitely need to clean and tin your iron tip.
Use a brass or copper "sponge" (pan scouring pad - but don't ever use anything but copper or brass, and don't use anything with soap or other cleaning agents in it).
Start by heating the iron up (for these kinds of irons, I always let it sit for about 10-15 minutes - then I hold it near my lips - about 1-2 inches away - and "feel" the heat rising - to have an idea of when it is up to temp - once there, I touch some solder to the iron - when it wets the tip, and the rosin smokes, I know it is hot enough).
Then apply a liberal amount of solder (really, you're just wanting the flux to clean it) - then wipe the tip through the sponge to wipe off the solder and the crud. Apply more solder, wipe again - keep doing this until when you wipe it, it leaves behind a nice shiny silver tip. When you have that, your tip is tinned and ready to be used. You should always clean the tip of your iron and tin it before putting it away, and before first use next time you use it.
If you don't have a copper or brass sponge - you can use a damp (not wet) cellulose sponge instead (this is the "old school" way - but still works just as good); be careful when you do this, too - because sometimes the sponge can catch the solder, bend, and "fling" it - sometimes into your face. It is always a good idea to wear eye protection goggles or glasses when soldering - sometimes the rosin in the solder will "pop" and fling solder about - basically, get use to burning yourself - solder will pop and hit your hands, land on your legs if you are wearing shorts, and on your feet if you're not wearing socks - but always wear some kind of eye protection, because you don't want hot solder on your eyeball! Also - at some point you will likely knock your iron off the table. Whatever you do, don't try to catch it. You WILL NOT catch the right end. Unfortunately, saying this and doing it are two different things. For many of us, we had to learn the hard way - but, after that first time, you'll never do it again - trust me!
:D :D :D
Now - once you have your tip tinned, the way I have always done it (once the parts are in place, held right, etc) - is to put a small blob of solder on my tip (I personally prefer a "flat chisel" to a "conical" tip like you have), quickly bring that blob to where I need it, then apply the iron to the joint, let it heat up (less than a second), then bring in more solder quickly to "fill in" the joint. After you have practiced this a while (do it on twisted wires, or practice wires in a solderable perfboard) - it should take less than a second per joint to perform. Then - inspect your work (I prefer a lighted magnifying lamp for this part - I also have used a handheld inspection microscope - today, there are also those USB microscopes), and reflow the joints where needed.
In between joints - wait a bit - maybe a second or two - to let the iron re-heat - when you make a joint, your tip of the iron drops in temperature, so you need to let it "rest" in between to let it come back up to temperature for the next joint to be made properly.
Also - tin your wires before you solder them - this is very important; you need to tin everything you solder before you solder it. In fact - the wires on resistors, capacitors, etc (most parts - not all, though - mainly passives) are actually "pre-tinned" - but you may want to verify this (or just tin all your parts). Setup is everything in soldering; get all your parts and wires in place before you start (as many as possible) - per "layer" of the soldering process.
What I mean by "layer" is that you solder parts on a board in a specific order - that of shortest parts first (jumpers, horizontal passives, etc), then next shortest, and so on - leaving the "tallest" items last.
Never try to solder a part larger than your iron can handle - it will just suck the heat out of the iron, and make your joints (if you make any) look like what you have already posted. Basically - parts and everything act as "heat sinks" - so your iron has to be able to dump more heat than the part can dissipate in order to heat the joint up enough to solder it. For most things - up to TO-220 cases - your soldering iron will be fine. For anything larger (ie - TO-3 and similar), you will generally need either a larger iron, or use mechanical methods (sockets or such) to attach wires to the parts (generally, for these larger parts, you'll need to use mechanical fasteners anyhow, because wires or such will be so thick for larger currents that soldering isn't generally practical).
Note also the "heat sink" effect - if you are soldering a part and fear overheating it - if you have room, attach an alligator clip to the lead before the body of the component, and the heat will dissipate through the clip instead of the part. For some parts that are temperature sensitive - avoid soldering the pins "in a row" - start from one end, jump to the other, and alternate - until everything is soldered - to distribute the heat load. For really sensitive ICs - solder on a socket instead of the IC.
If you can get a handle on soldering with one of those irons like you have - you'll be prepared for anything (then, when you get your first temp-controlled soldering station - you'll feel like you won the lottery).
Hope these tips help - good luck!