Instructables

Step 8: Desoldering, fixing mistakes and extrapolation

Desoldering:
Desoldering is the process of removing solder at a joint to disconnect two components, wires or materials. You might have to do this if you want to replace a component that's gone bad, or if you want to change something about your design once it's already soldered into place. To desolder wires you can usually just heat up the connection and wiggle them around until they come free. Better yet, if you have the slack, just cut the wire at the connections, strip, and resolder as necessary.

With leads that are mounted through holes on a circuit board it takes a little more finesse. To desolder something delicate its best to use a desoldering pump, or bulb which will actually suck up the molten solder and remove it from the joint. Soldering wicks or braided copper wire also work well to suck up unwanted solder. For more complete guides on desoldering check out Make Magazine's Learn How To Solder Skill Building Work Shop Video and this site here.

Fixing mistakes:
Soldering is pretty forgiving, and its usually pretty easy to fix a mistake. If you put down a little too much solder or position something incorrectly you can usually reheat your joint, melt the solder, and then reposition your component as necessary. Solder can be heated and cooled as many times as you need to get your joint the way you want it. So don't be discouraged if it takes you a couple of tries to get it down - you will still end up with a good connection if you stick with it.

Extrapolation:
Soldering is a pretty straight forward process but there is no limit to what you could create with it. Try to join things together. It works well for making jewelery, doing basic arts and crafts with small metal objects, or re-wiring your toaster into a heating element for an infra-red sauna. If soldering has been keeping you away from experimenting with circuits or making a project, hopefully it doesn't have to anymore. Once you do it a few times you might even start to enjoy it.

If you would like to get started on a few basic soldering projects check out instructables user Makekits and the Make Magazine Store to build things like a MiniPOV or a Daisy MP3 Player.

 
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Bradlez925 years ago
what should we do if we want the melted solder completely removed from the circuit board altogether? you mention some sort of pump, but that sounds REALLY exspensive and convoluted, when there is probebly a much easier way.
A less scary term for a desoldering pump is a "solder sucker." They aren't any sort of complicated pump for fluids, and can be as simple as a little rubber bulb with a plastic nozzle coming off of it. The ones I prefer are tubes with a nozzle on one end, a plunger in the other and a spring inside to push the plunger out quickly, sucking the liquid solder in through the nozzle.

In my experience solder wick works better. Put the wick on top of the "boo boo" and apply your soldering iron. You may have to move down to fresh wick and apply heat again to get all the solder. I have heard that braid from coax cable can also work for this although I have never tried it.

http://www.radioshack.com/product/index.jsp?produc...

Available at RadioShack although probably cheaper elsewhere.

fd93 Bradlez925 years ago
desoldering pump/iron combos are less than 15$ at the evil ones (radio shack)
TeamDuck3 years ago
Thank you so much, you helped me make my mum a sun jar in time for her birthday :)
kjjohn5 years ago
I am having a very hard time soldering together some mini camera charging circuits for a coilgun. I have to solder several wires that are each about a quarter cm long onto a board that is maybe a little over a square cm.
mrwolfe kjjohn4 years ago
You'll need a magnifying glass, tweezers, a very fine soldering iron tip and some fine solder wire (0.5mm should do it). Oh, and steady hands!
ya me to can any one help
kiler014 years ago
THANK YOU! i was rather discouraged to start soldering, not knowing how to do things, but now i see that it's not all that hard and bad. vel SMD is still pretty terrifying but anything else.... "can i really be the hero?" :) 
Great tutorial, I'm actually in the process of hot-wiring a few disposable camera's to a coil gun, and I was having trouble with the soldering. This should help a lot.
hi what guns are you making sounds interesting
kjjohn babbs1st5 years ago
coil gun, i am building one too, check out this instructable: http://www.instructables.com/id/Coilgun-Handgun/. Not mine, but this is where i learned how to build a coilgun.
Fun! For Halloween this year I desoldered the switches and flash tube from the flash circuit of a disposable camera and attached them to leads so I could position the tube and switches at opposite ends of my "Freeze Ray." I always meant to post an 'ible about it, but haven't got around to making it up yet.
Thanks for this, I'm one of those paranoid people who's terrified of everything and knows people are out there to teach me the right way to do things, this really did that and makes me feel much more confident. Thanks! You saved me a lot of time. Kudos
hotbottles5 years ago
Much obliged for the soldering tutorial. Got frustrated trying to rewire an input jack on a guitar amp. Now I see that solder is applied to the joint, not to the tip of the gun. Thanks.
jafrance6 years ago
Wonderful tutorial. I actually came across it while trying to prepare to go through your LED guide. My question is, where does flux come into play here?
briviere27 years ago
That was awesome! I especially like the MacGuyver soldering with a lighter and some baking soda haha, cheers!
u need baking soda to use a lighter to solder?
noahw (author)  darkstar247 years ago
To solder with a lighter you just need the wires, the lighter, and some solder. No baking soap necessary. I'm not too sure what you could even use it for, besides putting out a fire if your wire went up in flames...
surfwax957 years ago
This is a great, great tutorial. It's helped me so much!
wow that is nice you did great theres alot of very helpful info here thanks alot!! now I can go fix my remote controled cars! woohoo! Thanks again!
Chrislee7 years ago
Thank you, thank you all!!! I now realize that for years I've been trying to solder a lamppost with a flint spark. I'm going to try this again.
carlw7 years ago
Excellent posting. I'm going straight to the kitchen to rewire my toaster into in infra-red sauna (whatever that is).