Desoldering help


#1

i bought a 15 watt soldering iron from radio shack for the purpose of desoldering. i must be doing something wrong because my microswitch is heating up real hot and the solder just remains. the first couple tries it worked but i was too focused on the soldering wick so the solder just spread thin. then it just stoppd working on me o i took some solder and began to melt it to see if it works at all i noticed that it olny melted the solder in one specific area(tiny tiny area). even still it wouldnt heat the remaing solder into liquid. i saw a desoldering iron at radio shack and saw that it was 45 watts. will this solve my problem? what the hell am i missing about soldering thats F’ing me up?


#2

You bought a soldering iron for the purpose of desoldering when at the same exact place you purchased the soldering iron from they have a specific tool for exactly what you’re trying to do?

Take it back and get the desoldering iron. It’s only $11 and I have one as well. Its pretty awesome just remember to spit out all the solder you sucked and to not let it build up inside of the sucker.


#3

Get some desoldering braid and [media=youtube]mjme2VLpIpw"[/media]. Fast forward to 8 minutes.


#4

this is what I use and it works great… way better then the braid


#5

lol i was going to get a desoldering iron but i figured if i get a wick, i can still have something to solder with just in case. but now i just regret it. lol im supposed to take my stick to AK’s. hopefully by the time i get back, i can hop on sf4.


#6

did you get a desolder bulb too? I’ve used a combination of both on my first mod.


#7

i just think its my iron.

i shouldve bought that instaed, braid is a pita.


#8

You actually don’t need any of that stuff. You just needed to re-tin your tip. Always clean off your tip after each use, either with a wet sponge or a steel wool ball, then re-tin. The soldering iron tip becomes oxidized easily and that will block the heat transfer. (that’s why the solder only melted on a particular point on the tip & not everywhere like it should) If the oxidation is really horrible, you can scrape it off with sandpaper or something, then re-tin.


#9

whats re-tin? i did wipe in a sponge after every use. and the tip just kept getting brown and just malfunctioned on me. could it be that the iron itsefl was defective? it was less than 10 dollars and i bought it from radio shack


#10

re-tin means to apply solder onto.
if ur solder tip turns brown u can try to sand it off with fine grit paper then tin it.

after every use, while hot, wipe it with a sponge quickly while u turn the tip try to avoid a soaked sponge. if ur iron cant melt the solder left on ur tip… then replace ur tip.


#11

Tinning is getting a little solder on the tip of the soldering iron.

If your tip has become oxidized (not shiny, brown, whatever) it isn’t going to conduct heat, and it won’t melt the solder. Try wiping it off on the sponge. You may need to scrape it off with some steel wool or sandpaper or something. Replacement tips for the cheap Radio Shack irons (which I use) are also pretty cheap.

There is nothing wrong with using the braid; it is easy to use when your iron is working properly, and the results are clean. Desoldering bulbs are a PITA IMHO, at least for smaller bits of solder.


#12

Yes, de-soldering irons are a waste of money IMHO. A decent soldering iron with some braid and flux is all you need.

You seem to have two problems on your hand. The first is that you did not clean and re-tin your iron as mentioned. You need to do this quite often to maximize heat transfer.

The second problem you had is that the solder wick is most likely oxidized as well, so when you dip the wick in the melted solder, it doesn’t soak up very much if anything. This is where the flux comes into play. Flux is an agent which gets rid of oxidation and thus encourages the adhesion of the solder. You should buy a small bottle of flux and then squirt a bit on about 3mm of the end of the wick, a little goes a long way.

Flux is the same stuff that causes solder to smoke when the solder has a ‘rosin core’. The ‘rosin’ is actually flux so that when the solder melts, flux is also released to encourage adhesion. You can buy rosin free solder in which case a bottle of flux is necessary to put solder on as well.


#13

I would strongly advise you to NOT follow this video tutorial, the desoldering job he did was very poor. For one he did not clean and re-tin his iron before applying it to the braid. Two, he did not use any flux on the braid (which is more forgivable.) As you can see in the video, the lack of doing these two things required the iron to be applied to the board much longer than it should have. This will lead to burning the top layer of the PCB and could potentially damage other components by heating up the copper traces that connect them together. You can see the damage he did in one of the shots of the video, luckily it still seems to be functional.


#14

Personally, I only use braid for small things like desoldering surface mount components, and the pump for larger spots.


#15

I’d recommend re-tinning your iron like everyone else said and see if that helps. It also sometimes helps if you add some new solder to the spot before you try to desolder off with a wick as well.


#16

On the subject of oxidized tips. I have holder that I slide my iron into, but with the weight of the cord the top of it touches the sisde of the holder and that side of the tip oxidizes like crazy despite my tinning attempts. Do I need a new holder or is there some trick to this?


#17

Get a desoldering pump like this: http://www.dealextreme.com/details.dx/sku.13418

I have the exact same one and it works a dream. No messing around with multiple irons, no braid/wick to run out of. You press in the plunger till it locks, apply heat to the solder you want to remove then position the pump and press the button.


#18

1esproc thats identical to the one I posted

yours is cheaper however I question the longevity of it.


#19

I just did my first soldering job last night on my fs3. I used a 25 watt soldering iron with a braid. I think i tinned (if thats a word) the iron correctly, but the iron still got oxidized.

When I touched the iron to the braid, it seemed like it took forever to melt the solder, even when i re tinned the tip. After 45 minutes, i had the 16 points on the hori pbc was desoldered.

After the iron cooled down, I took some sandpaper to it to clean the brown off. It only took me 4 minutes to solder everything back together. I really liked soldering and cant wait to do it again.


#20

I used to have the same problems you mentioned. It was a combination soldering iron problem and tinning problem. I then got a good soldering iron as a gift and never had that problem again. Seriously, once you have a good soldering iron, it never takes more then two seconds for the solder to melt, and you generally don’t run the risk of melting your components. I don’t really know what makes it a good soldering iron, if it gets hotter or conducts heat better, or just has a different tip, but it works great. It was one they had been using at this high school and when they upgraded, they gave the old irons away.

I do have a seperate desoldering iron from RadioShack. It works pretty good, but after you suck up 90% of the solder, you have to pull the parts apart, otherwise, the 10% that is left will just stick them together.