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I'm fairly new to electronics and am having some issues with soldering and could do with some advice:

  • from what I have read the solder shouldn't directly touch the soldering iron when solding the component. However, I find the component I.e. a diode, gets incredibly hot before the solder has melted and I'm worries this will damage the component.

  • the solder won't stick to the circuit board material (I'm using a brown board which has lots of holes already in place (I'm sorry I don't know what it's called) the other issue with this is the board also looks like it starts to melt or discolour a bit when I'm soldering.

  • the soldering iron I'm using is a kit from Maplin, it is 40w and includes a lead free solder.

I also have a 12w iron which appears to be useless.

  • I seem to get a big blob of solder off which just bonds the wires together and doesn't bind to the board!

Any advice, tips or tricks or if you could signpost me to a video etc about how to best get started is me most greatful as I'm really struggling to get off the ground and it's very disheartening.

Many thanks,

James

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    \$\begingroup\$ You should use lead-tin rosin-core solder until you have more experience. \$\endgroup\$
    – Scott Seidman
    Commented Jan 2, 2017 at 20:13

2 Answers 2

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With lead free solder it is more common than not that you will need to add additional flux. That's especially true for a board or components that have the surface tarnished at all.

Solder only touching the component made more sense in the era of through hole parts and leaded components - in many other situations today such as fine pitch surface mount it does not apply as strictly, or perhaps at all. You may also find that even in the through hole situation, solder on the iron can increase the heat transfer by filling the space between the iron tip shape and the lead / board.

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  • \$\begingroup\$ Hi Chris, that's great thank you. In terms of adding flux - I do have some but is it just a case of swearing a small amount on and does it burn off when soldering? \$\endgroup\$
    – user134754
    Commented Jan 2, 2017 at 17:46
  • \$\begingroup\$ To avoid overheating the component, you can hold the heated lead with tweezers, so they could dissipate the heat before it gets to the component. There are plenty DIY videos on how to solder. Just google it. \$\endgroup\$
    – Nazar
    Commented Jan 2, 2017 at 18:39
  • \$\begingroup\$ Hi Naz, yes that's where I started but the videos I have found suggest not to heat the solder directly, soon essence the component gets all of the heat until the solder melts and you can remove the iron from it... :/ \$\endgroup\$
    – user134754
    Commented Jan 2, 2017 at 19:00
  • \$\begingroup\$ @Reyno You have to use flux which is made for electrical/electronic work - the sorts which plumbers use will destroy things after a short time. You should clean flux off afterwards: Removing rosin flux residue from PCB. \$\endgroup\$
    – Andrew Morton
    Commented Jan 2, 2017 at 19:34
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There's no reason why the solder shouldn't touch the soldering iron. Don't worry about that. Put the iron on the components only a short time before you apply the solder - just long enough to warm up the leads. That is unlikely to be more than a second for small components.

Make sure that the iron has been tinned (a little solder applied to the tip) before you make the joint. That helps conduct the heat faster. If the tip of the iron is dirty, clean it first. But beware of grinding off the surface of a special plated soldering iron tip - wiping on a slightly damp sponge is usually all it needs.

If you are melting components or boards, it's taking far too long. Soldering small components should only take a couple of seconds. The wattage of iron you need will depend on the size of things you are soldering. The bigger the components, the bigger the iron it needs. 40W should be plenty for most electronics.

If the solder won't stick to circuit boards or component leads, then they are probably dirty. Copper boards should be bright and shiny. So should component leads. If not, clean them with a fine abrasive.

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  • \$\begingroup\$ Actually, it's MUCH better to heat the joint and let the joint melt the solder than to use the iron to melt solder onto a cold joint. \$\endgroup\$
    – Scott Seidman
    Commented Jan 2, 2017 at 20:12
  • \$\begingroup\$ @ScottSeidman yes, but that overlooks that heating the joint often works better when there is already some melted solder on the iron to increase the heat conduction to the joint. \$\endgroup\$
    – Chris Stratton
    Commented Jan 2, 2017 at 20:25
  • \$\begingroup\$ @ChrisStratton -- of course. That said, the application of solder to the iron and joint at the same time just isn't great technique, and advice like that without a description of how to avoid cold joints will result in cold joints. \$\endgroup\$
    – Scott Seidman
    Commented Jan 2, 2017 at 20:31
  • \$\begingroup\$ I've updated the post a bit. \$\endgroup\$
    – Simon B
    Commented Jan 2, 2017 at 20:51
  • \$\begingroup\$ Thank you all so much for your responces, one other thing I wanted to say was that the board I have been using is like veroboard however, its not shinny on either side I.e. copper etc. Im wondering if im using the best thing for putting together basic circuits? Thanks \$\endgroup\$
    – user134754
    Commented Jan 2, 2017 at 21:23

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