need some soldering advice

[tesco]

To begin what do you mean by you couldn't get the wire hot enough? Hopefully you mean the solder because you shouldn't heat the wires at all.

Tesco may be the final arbiter here (being an electrician and all) but I think this is wrong.

Of course, you always heat what you're soldering or welding.
But I don't ever do soldering, I never really mastered it, so can't give any other tips. I've never tinned my soldering tips before.

[Appzalien]

Preparing a soldering iron. With a brand new tip you just dip it in a little flux paste and then add some solder to the part of the tip you would be using to apply with as it heats up. This is called tinning the soldering iron. If the tip becomes discolored before you can get solder onto it, clean it with a file or sandpaper then reflux and try again. As you use a properly tinned iron, the spongebob is used to clean the tip between jobs as it will collect some cruddy black stuff and the wet sponge will wipe it clean and shiny again.

When soldering wires you should strip them to the size you want and apply some flux, with a small drop of hot solder applied to the tip of the iron heat the wire with the drop and at the same time keep trying to add more solder to the wire with your solder, when the wire gets hot enough the solder will flow and melt from the application stick to the wire and flow throughout. If the solder gun doesn't quite get hot enough you sometimes have to solder one side then the other to complete this task. If you want to join two wires you can either twist them together and solder, or tin the two wires separately first, and then heat them together. The second method is neater and works great along with some shrink tubing to cover the bare wire but its a little trickier and would be easier with three hands (the alligator clip thingy).

Remember to put electrical tape around your wires to prevent shorts and when joining something like an electrical cord (lamp plug etc) its a good idea to alternate your wire cuts so that the bare sections cannot touch one another:

------------ --------------
------ --------------------

Once you have learned to tin an iron or gun tip and start using flux paste on all your project parts you will find it goes alot easier.

[Col. Skillz]

well ive got a good iron now, and have tinning down pretty good. i can kinda tin a 30 awg wire, but the wire is so thin i have trouble heating it up, and im never really sure i got the solder on it =/

my main problem is getting a drop of solder on the "connector". Im testing on an older motherboard, just trying to get a little glob of solder to drop somewhere on the board. I really can't do it..it sticks to the soldering iron. even if i use a bunch of solder, it just sticks to the soldering iron and wont fall off. the only way i can get it off is to do some messy thing where i slide the iron with the glob of solder across teh board, but im not sure that makes for the best connection.

on a positive note, i can easily heat the tinned wire and solder glob together pretty well. i did one and it took a lot of tugging for me to get it apart.

what i need now is to master tinning the wire, and some detailed info on getting that "glob" onto my board. can anyone describe in steps or details what ive got to do here? right now im just touching the connector with my iron and then melting solder between the iron and connector. but i like i said, the soldering iron just sucks it all up

[lynx]

It's down to cleanliness again.

If there's old solder on the board, it will have oxidised to some extent, so you really need to remove it. This is where the desoldering pump comes in. Push the piston down, melt the solder then put the tip of the pump against the molten solder and press the button to suck it up.

Old PCBs often have a thin layer of lacquer which won't help the soldering process, so once you've got rid of the old solder you need to clean the area with alcohol then smear a little flux on to it, and apply the soldering iron. Get it hot then apply the solder as you described. You don't need a mountain on there.

As for pulling your joint apart, you shouldn't be able to do that, the pieces you've soldered together should break first, not the joint.

BTW, here's a tip for melting old solder. Solder used in wave soldering on PCBs often has a higher melting point than ordinary solder and can be difficult to melt. The trick is to add some of your own solder which helps conduct heat into the old solder and the combined alloy also has a lower melting point. Once you've melted the old solder remove it with the desoldering pump.

[Col. Skillz]

thanks for the useful advice once again =) this pcb is definitly old, and id believe there is laquor on it, its very shiny and feels like coated wood or something. I'll have to clean it with some alcohol then?

about the pulling my joint apart, what is the joint? the pcb and glob of solder, or glob of solder and wire. the glob of solder came right off the pcb (which is what i worry about the most) but the wire took some beating for it to break off, and it was the end of the wire that broke, nothing to do with the solder just me pulling on it.

[Appzalien]

The pcb board is made in layers and usually where a track of wire under the coating ends there will be a larger round part and a hole that is exposed copper on a blank board and will be silver with solder on a build board. If the piece gets bad enough (oxidized) it may not take any solder even when using paste flux to clean it. At that point you have to somehow clean the thing down to silver solder or copper base before you can re-tin it. You have to be careful here cause the metal is hair thin and can be pulled up from the board rather easily, especially after several attempts and heatings. You can carefully scrape it with an exacto knife or try a little sand paper wrapped around a q-tip or small rod of some sort or use one of those grinding tips for a dremel tool to clean it but not with the tool itself, do it by hand or you can do some horrible damage.You can also try using that sponge to wipe the section after you heat it and sometimes it will work just like it does for the solder iron tip.

I have repaired boards where the circle part came off by scrapeing away the coating of the actual track of the wire and adding a glob as you call it to there and using wire to connect the part that went there. I have also repaired a cracked board by jumping out the crack by removing some of the coating from either side and jumping over the crack with wire.

As you get better at it you will find this hobby quite rewarding. Along with a multi-meter and a wire stripper (there are some really fancy ones) you will be repairing things other would throw away. I actually repaired one of those mp3 players that are hardly bigger than the AA battery that goes inside, talk about some fine work, Whew!

[Col. Skillz]

hey thanks for the tops mate, im going to practice some more to day hopefully with some improvement

i never thought of it like that, being able to fix electonic equipment..id probably need to learn about all the other pieces on a circuit board though, no? and i do havge multimeters and trying to learn how they work, but damn, im confused. i want to use it to check if my batteryes are dead, but i hear the only way is to have the battery being used while i test, but how the heck can i use and test it at the same time =/

anyway, ill probably be back tonight with more questions after my soldering practice goes belly up lol =p

[Detale]

Who said you have to use a battery to test it? Touch the red lead to the + and the black to the - and it will give you a reading man.

[clocker]

One thing to be aware of...
Motherboards are made of layers and some components need to contact traces inside the board, not just the ones on the surface.
This is particularly true for laptop powerports- in my experience, the most common repair necessary.

"Fixing" dead electronics is a very iffy procedure...it can certainly be done but one must balance the time factor against replacement cost.
A very common problem is blown capacitors, which was endemic about 5 years ago as substandard parts flooded the market.
Problem is, these boards are now part of a completely obsolete platform and one must question if spending any time at all makes sense.

[Col. Skillz]

Who said you have to use a battery to test it? Touch the red lead to the + and the black to the - and it will give you a reading man.

err i read somewhere that the battery needs to be in use to get an accurate reading. like in a cd player with it playing or something of equivalence.

i know to read the battery i touch the + and -, and look for a voltage thats around or slightly less whats its meant to for the battery. like a 9v would be 9, AA's are 1.4v i think

but the guide i read on multimeters told me it wont be accurate if the battery isnt in use.