So the tip of my soldering iron is completely worned out and it won't take the "lead free" solder anymore and won't stick after I clean it. Since now, I'm deciding to switch my solder iron tip to a conical to a chisel tip. Now, I was wondering if the chisel tip is much better than a conical tip (which I use all the time), because the chisel tip is better for soldering and desoldering circuit boards.

how are you cleaning your soldering tip on your iron?
 
I have not replace soldering tip on my iron in 2 years
and i use it 3 times times a week.  trick is you heat up the iron and tin it with solder.  before you put your iron away for the day you dip it in flux then wet sponge then tin it. and repeat process until your tip is shiny with solder and let it cool off. 

but i use my poorman soldering iron more than anything
else.  6 volt battery and pencil lead and solder
and some jumper leads. and yes I solder dip ICs with this on the board.  cause it heat up faster at fine point than my soldering iron would do. and I have more heat control.

never use sand paper to clean your soldering tip.

how are you cleaning your soldering tip on your iron?
 

I usually clean it with this:

 trick is you heat up the iron and tin it with solder. 

Plus, I usually tin it when its fully heated up, and clean it with the gold stuff.

One detail that helps a lot but very few people do it:
Before putting the tip on the stand, just after cleaning it, wet it with fresh solder. Then just before using you have to clean that solder away because it degrades when sitting hot, but it provides excellent protection for the tip itself. The drawback is, you spend extra solder on it.

Regarding the cleaning: This metal cleaner is better than the wet sponge, mainly for the lead free (= higher temperatures involved), because it does not stress the tip thermally. The big mistake people do with sponges is, they have them really dripping wet and not just slightly wetted. Again the result is larger thermal shocks on the tip. The metal cleaner does not need any wetting, so there is no problem with excessive amount of water or so.

For the bad tip: Because it seems already ruined, you may try some more aggressive method, but still be careful. The tip is usually of copper body, with an electrochemical iron coating to provide barrier between the tin solder and the copper (otherwise the copper dissolves into the melted solder). This coat is then wetted by the solder.
Because you used mainly dry cleaning, it is very likely the tip is just dirty (carbonized flux residues) and not that much corroded, so careful scrapping with some knife or so may remove them and then you may be able to revive it.
But do not expect this to be a reliable method. Depends on the iron layer quality, there is high probability the layer cracks (and that could be caused by the scrapping), let the tin underneath to dissolve the copper, or the oxygen to oxidize it and the tip is the dead for good.
So not good method for a working tip, but usable if your options are just trying it vs throwing the tip out right away.


For the tip shape, I bought selection of about 8 tip shapes (and sizes), but practically all the time use just the 2.4mm "D" (remotely like a flathead screwdriver), for really fine work alternating with 1mm, for high heat demand 5mm, all "D's". To me it offers good thermal conductivity, yet it still has rather narrow edge for small things. I use the compact tips integrated with heater, with a home made controller. These tips are really quick, so it is practical to use the "idle" mode - when not moving (so on the stand), it drops the temperature and reheats when you move it. I set the idle time really short (15 seconds), the idle tempperature at 200degC (so the solder just remains liquid; I use leaded solder, for lead free the ideal idle would be about 230degC - about 20degC above the melting point).

I think how well does the rod clean or withstand the cleaning procedures depends on the quality of metal used. With the same moist sponge treatment, Hakko, Weller, etc rods seem to hold up fine and clean up nicely every time, while the rods of some "hardware shop" irons will just disappear with use like a pencil being used up

(Some of the "hardware shop" irons do simply overheat, because they are not thermostatically controlled and are built to err on the "hotter" side so prolly get to 480+ degC if left plugged in for long time, and this may be a contributing factor too)



As for the shape - I have used all of conical, chisel, and "round rod cut at an angle" style tips, mostly with leaded solder. The ones that have a flat surface have advantage that the solder tends to pool on the flatter areas, so while for the conical this means "away from what you are trying to solder", for the others it just means that you have better control over it. Hakko T12 chisel tips even seem to be a little caved-in, maybe for improving the effect



Btw, for anyone who still uses "hardware shop" iron and wants a hack to turn it down a bit to prevent the overheating problem : Use an ordinary GLS dimmer. Or connect it in series with ~70W HID ballast and a bypass switch. But really, if you solder more than once in a while, it's good investment to get a proper thermostatic station, even some of the Chinese ones off ebay are fairly decent. (Not the ones where the entire system is in the iron handle though !)