I have had a soldering iron for many months now, and have soldered numerous times. When my cheap $5 iron finally gave out, I knew it was time to go for a more expensive one. So, I went to Radioshack and got a ~$30 iron. It looked great, until I turned it on. After one use, it looked like literal crap. After three or four uses, it was barely working properly. After seven to ten, I could see the copper core of the tip. I was so mad! A $5 iron thoroughly outlasted a $30 one! I had my $5 one for about 6-8 months, and this $30 iron for a few days. So, we returned it and I got a $10 one from Radioshack. This one has been with me the last few months (although it's been used far less than you would expect during that time), and today I turned it on and tried to setup a 3.3v regulator board. When I was soldering in the regulator IC itself, the first step, my soldering iron could not keep the solder properly heated! It would clump and solidify quickly, and failed to make a solid connection with the copper pads. I tried re-tinning it, using soldering iron cleaner ($10 from RadioShack!), and anything else I could think of. I think my iron is finally over, after minimal use. What the heck! How does a cheap, $5 iron from a no-name brand FAR outlast any more expensive iron! What can I do! The tip looks ok, what is happening?
I have a Weller WESD51 that has worked very well - it has a controlled temp. on the tip you can set. Make sure you are cleaning the tip (I usually just use a damp sponge to wipe the tip on most of the time). I assume you are using rosin core solder ? Overheating a tip (like an uncontrolled iron) will definitely degrade the tip life (and you want one with replaceable tips - either for a different shape or when one wears out).
Too expensive for me, sorry. I dont have a controlled temp iron, i have the "RadioShack 5-Piece Basic Soldering Set". I use rosin core, lead free solder and has always worked well. Why is this getting broken?!
Part of it comes down to "you get what you pay for". An uncontrolled iron tends to run too hot if left on which tends to eat the tips. I also tend to stick with standard tin/lead solder - the lead free is a bit tougher to work with (just my preference - no longer making things that fly in space 
)
A Weller with replaceable tips is a great investment. I have two Weller workstations and I bought a cheap SMT rework station for less than $70 that is working fine also that has excellent temperature control.
Having temperature control is very important as well as the size of the tip for the type of work.
If the work area is too large for the tip, heat loss is too much for the iron to keep up and will result in a cold solder joint. Too hot of a tip can cause damage to the components. Keep your iron's tip tinned and clean, use flux and clean your solder connections before and after.
An entry-level temperature-controlled soldering station is not much more expensive than a Radioshack iron. However it is much more useful for more things.
Need a hole in an ABS plastic box to run a cable through? Set your iron to 240C and just melt a hole. At that low temperature the plastic melts without burning.
Heatshrinking and you don't want to reach for your hot-air gun? Set the iron even lower and shrink away.
Need to rip the humongous DC input connector off an Arduino board and it's soldered with some difficult lead-free solder? Crank the temperature up all the way and just be careful you don't burn the board too much.
So let me tell my story
I got a soldering iron for over 10 years, a 30w one from Germany, soldering pretty good and really high heat for 30Watts
after soldering so many years few weeks ago it burned completely so because I didn't had big budget to upgrade to a better one, you know the one with automated or manual heating with hot gun that cost about 50$
I took one from my local electronic market with 2.5$ 
A the most simple iron that i ever took it described that it's a 30wat one but didn't even pull 10W. so what I done? I carefully opened the iron inside I saw a coil, so because I had experience in the past with nichrome wire I knew what to do, I unwrapped the coil not all of it and cut about 10cm from it or from my coil length about 5~10~15%, I wrapped back, assembled the iron back and now I got a +40Watts Iron, it's heating up
more and now I can solder perfectly without any cold soldering anymore.
But you need to be careful do not cut a lot, the coil can burn out or your soldering iron can melt down
bobdabiulder:
Too expensive for me, sorry. I dont have a controlled temp iron, i have the "RadioShack 5-Piece Basic Soldering Set". I use rosin core, lead free solder and has always worked well. Why is this getting broken?!
https://www.radioshack.com/products/5-piece-basic-soldering-set?variant=5717865349
I'm a decent solderer (for an engineer...an excellent tech once graded me a C+ and I'm proud of that), but I wouldn't attempt to work with lead free solder with a $5 RadioShack iron (btw...they still exist? All their stores closed by me). It's hard enough to work with lead free solder using good equipment. Is there a reason why you chose lead free?
I think you're learning about cheap tools the hard way. They cost reduce them to the point of where they're practically disposable: they'll work alright out of the box for a while, but if you expect to need it forever you'll spend less in the long run by getting one good tool instead of regularly replacing disposable ones.
Soldering stations are expensive, but there are tons of used ones on ebay that are listed for half price with 0 bids -> Ebay Search: weller soldering iron -vintage
I'm sure if you bid on enough of them, you could get one for $20. I'd recommend getting a Weller as it will last forever without being crazy expensive, and you'll be able to get replacement parts for it if needed.
They have cheaper Weller irons on there too, if getting a used station really is out of your price range. Even though I own a station I still use my old iron from college whenever it's difficult to bring the work to my bench. It still does just fine for small stuff, even after 20+ years. They have one listed on ebay for $25 -> WELLER-WP25-25W-SOLDERING-IRON-GUN-TOOL-BLUE-HE25-120V
BigBobby:
stores closed by me). It's hard enough to work with lead free solder using good equipment. Is there a reason why you chose lead free?
Absolutely, lead free is tricky even with a temp controlled iron.
Different mixes have different temperature sweet spots.
Lead tin is much easier.
Reworking lead free is also a problem , often removal of the solder is required to make good a joint.
Thanks guys. Just to clarify: my OLD generic iron was $5, my new one is $15 and the other one I returned was a two temp $30 "workstation "
bobdabiulder:
Thanks guys. Just to clarify: my OLD generic iron was $5, my new one is $15 and the other one I returned was a two temp $30 "workstation "
Hi Bob. I have always used the cheapie 30 watt Radioshack soldering iron. I replace the tip as needed, and when the iron itself gives it up (after a few years), I spend seven to twelve bucks to get another.
you can buy the iron with tips and cable for any of the major brands. ebay for not too much.
and, you can build your own electronic control for it.
Finally some better posts. I am askin more about cleanin and why is this thing so quick to wear out, and I'm NOT asking for a shopping list! Thanks.
bobdabiulder:
Finally some better posts. I am askin more about cleanin and why is this thing so quick to wear out, and I'm NOT asking for a shopping list! Thanks.
Oh. My re-read of your OP sounded like you were complaining about the short lifetime of cheap soldering irons from RadioSnack.
Perhaps (and this is more shopping list stuff) you should buy tip replacements that fit one of the irons that you have. Then when the tip stops functioning correctly, replace it! 
On the other hand, double check the solder you are using. Plumbing solder often has an acidified rosin core - good for cleaning the copper pipe, but very hard of small soldering iron tips. And electrical connectors.
I clean my iron with a slightly damp, regular cellulose sponge, like you might find in an old person's kitchen sink (those new-fangled plastic, scrubby things do not work right.) When you are done with a job, clean your tip right before turning it off, not after turning it off, as residual moisture may hasten corrosion.
Aside from that, if you use cheap irons (like I do) get used to the fact that they may wear out faster than higher quality irons. That said, I bought a $2 soldering iron at Fry's a couple weeks ago. The handle got so hot I couldn't hold it, and it gave off a smoke that smelled like it had biological parts inside. So there IS such a thing as too cheap.
BigBobby:
I'd recommend getting a Weller as it will last forever without being crazy expensive, and you'll be able to get replacement parts for it if needed.
I'm a big fan of Weller. If my old WP-40 finally bites the dust before I do, I'm going on eBay hunting for that same old discontinued model, and I will expect to pay $15 to $45 USD for it used. Tips are available (and have been available for dozens of years) in a variety of shapes, and my favorite now is the ST7 tip. I can't remember a tip going bad, and I use them for years. I just change them out for a different shape. I can solder anything with this thing, SMD rework, electrical stuff in my truck, household wiring, through hole wiring, brass pipe soldering, desoldering with braid, Chip Quik, etc.
dmjlambert:
I'm a big fan of Weller. If my old WP-40 finally bites the dust before I do, I'm going on eBay hunting for that same old discontinued model, and I will expect to pay $15 to $45 USD for it used. Tips are available (and have been available for dozens of years) in a variety of shapes, and my favorite now is the ST7 tip. I can't remember a tip going bad, and I use them for years. I just change them out for a different shape. I can solder anything with this thing, SMD rework, electrical stuff in my truck, household wiring, through hole wiring, brass pipe soldering, desoldering with braid, Chip Quik, etc.
Lol...just curious...how doesit do with Lead Free solder?
I'm still waiting to hear from the OP why they're using Lead Free solder. I have a feeling most of their problems would go away if they went to Tin-Lead.
Unless you're making consumer products and ROHS or something, I can't imagine why you'd make your life more difficult with Lead Free. Maybe the OP has to do all of their soldering at the kitchen table and worried about lead poisoning?
No lead free solder here, I use 60/40 rosin core. At the kitchen table.
Kester 60/40 here too. I love the smell of hot rosin in the morning
I have an X-Tronic temp controlled iron that is absolutely top rate. When it comes to tips, I use standard rosin core solder, I clean the tip before each use by brushing it across a little Scotch-Brite pad. I solder at 425 deg.
My tips last a very long time, probably through 60 hours or more of soldering. I don't know what the flux is for lead-free, but perhaps it is more corrosive than rosin. I suggest you try leaded solder and see what happens.
I've been soldering with leaded solder for at least 63 years, (started playing with radios when I was a kid); if it were going to kill me, I'd have been dead long ago. Just don't eat it.
gpsmikey:
Kester 60/40 here too. I love the smell of hot rosin in the morning
Please forgive me if I'm completely wrong, but you're retired right? Heh...I thought I was old on here because I'm 40+, but I think you're old enough to be my dad aren't you?
Hopefully I didn't just make an ass out of myself, but anyway...would you believe that I had to pay $2400 last year to get rid of the lead in my house in MA? I got $2215 back in taxes, but still...the government was so scared of lead that the cheapest way for me to get it removed was to get certified to be a licensed lead remover, and then pay a licensed lead inspector to prove that I'd removed it correctly (and he sent the samples out to a licenesed lab to get tested!)...
Given how the 6.13 generations that grew up in my current house fine show how people can live with lead without killing themselves, I find that all pretty ridiculous.