SparkFun Forums

[emaayan]

hi..

i think i might be missing something with the 3rd hand, my main activity now, is to solider wires to a board (like power wires to IOIO, or wires to a current sensor)

now the best way to do so , as i look at it is to have the board upside down trapped by one arm, a wire in the other, and hold the solider and iron myself.

there are to problems , the first, is that i switch on the the iron and try to position the board horizontally, my hands are VERY close to the iron holder, (which is also hot), and i have fight my way through it.
the second problem, is that i understand you don't need to have the iron and solider both on the wire, but have the iron , heat up the wire then apply the soldier letting drip to the board across the wire, BUT, it doesn't work, i have a 25W iron (i understand you need 25-30 for electronics) and you need to bring iron the solider really really close to each other on the wire, otherwise i'm assuming the heat dissipates before it has a chance to melt the soldier. on the other hand i don't want to touch the board accidentally with the solider as it might damage it.

[AndyC_772]

It's true you need the use of 3 or 4 functioning hands to do some tasks in electronics, but they do seem to develop with experience. Soldering is a practical skill, and practice makes perfect.

The technique for getting a good solder joint is to apply the tip of the iron to the joint, allow the joint to heat up, then apply the solder to the joint rather than directly to the tip. The wire should be hot enough to allow the solder to melt - and if it isn't, the solder won't stick to it properly anyway.

Failure to get enough heat into the surfaces to be joined is a common cause of poor solder joints among inexperienced engineers. For some reason we're taught to avoid overheating things, but I've seen a lot more failures caused by dry joints than I've ever seen as a result of too much soldering heat.

A little molten solder on the tip can aid heat transfer into the wire, but there shouldn't be too much; only enough to wet the surface of whatever it is you're trying to solder. Once the joint is hot you can add the extra solder to the joint, then leave the tip in place for a couple of seconds until you can see it flow all around, and only when it's stopped flowing should you remove the iron.

[emaayan]

that's what i'm saying even with molten solider on the tip, nothing flows unless i bring the tip and solider 2 mm next to each other on the card, could it e that i need a stronger iron tip?

actualy i think i mess up my current sensor because of solidering as connecting multimeter's ground and vin suddeny give me 2.5 volts, (and as i far i understand just connecting them to these sockets is like connecting both multimeter's tips to each other which should give me zero.

[motopic]

Try using a flux pen to flux the joint.

You are using electronic solder right? It should be fine wire type (not 1/8" diameter pipe solder)

1-2 seconds MAX to heat and solder a joint.

25w is a bit small, I use a 70w (analog from SFE)and its definitely fine.
One thing, is each tip is different, and most have a 'hot spot', and its usually not at the tip.

Finally, be sure to look at the SFE (and other internet) soldering tutorials, video helps demonstrate much better than text messages.

[emaayan]

ok, i have no idea what flux means (i'm guessing not a flux capacitor).

as for the solider i've got no clue, but i think it's this one : http://www.zicotech.com/index.asp?mode=products&id=320