Episode: 1047
Title: HPR1047: Soldering Part 2: An audio demonstration of soldering
Source: https://hub.hackerpublicradio.org/ccdn.php?filename=/eps/hpr1047/hpr1047.mp3
Transcribed: 2025-10-17 17:55:00

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Hello, Hacker, probably do audience. My name is Mr X and welcome to my second podcast
in soldering. Hopefully it hasn't been too long since she heard the first part and
it managed to gather together all the bits and pieces that I mentioned in the last podcast.
This podcast is going to be a bit more free-flowing than previous podcasts so I may tend to ramble
a bit and um and all and things like that so I apologise in advance. I don't really know
how this is going to work because this was really ideally it should be done with a video
camera and at least taking pictures but I thought I'd just have an attempt to talk through
shoulder joints, making a shoulder joint. Okay so I've got everything gathered together
ready to try some soldering. I thought today we would talk about how to keep your
shoulder in there and clean and how to produce a good joint and probably the most common
thing you'll do is remove a wire from a circuit board and reattach it perhaps or perhaps
join two pieces of wire together or maybe fit a simple component such as a resistor
onto a circuit board, something like that. We'll tag one through that sort of thing.
Okay so what I've got here I've got my soldering in front of me and you can stand here that's
satisfying click, marvellous. Right, okay now we also have a solder sponge, small work
cutters. I've actually got a pair of long nose pliers that can kind of be handy sometimes.
I've got a pair of tweezers and I've got an eyeglass because I've got one key eyesight
these days. Right, oh and not forgetting of course the most important thing I've got
a multi core flux impregnated shoulder and a few resistors as well just to try soldering
those. Okay so the first thing you need to do is obviously switch on your soldering
amp so we'll do that now. Okay and I've set it mind to 330 degrees and it's now reading
65 degrees and all of a sudden it'll start climbing off so I've got a way in that heating
up. Yep that's hot already. Not a temperature though. Right, I'm just going to heat it up.
So how do you go up to the temperature? I've now got up to the temperature and I've had
a few seconds, I've got up and down now. Right, okay so before you start the first thing
that's important is your soldering amp has to be clean. Now when I look at my soldering
amp I'm the tips lovely and shiny and you should be the same. If it isn't then you can
tin the soldering amp and I'll tin the tip or wait the tip, whichever you want, whatever
you want to call it. Well that entails doing is you basically cover the tip and solder,
sit a bit a few seconds, so I'll cover it just a wee bit and take the amp so it goes all the way
around the thing and then wipe it off. Okay and then it's lovely clean silver tip. If you haven't got
a temperature control down or thermosatically controlled down then you may find your iron runs a
bit hot and it may be a bit black and not very easy to keep clean. That's one of the problems
with non-temperature controlled iron's I'm afraid. Okay so that's a nice and clean. Okay so the
secret to soldering is flux. You can get flux in various formats, you can get wee bottles of
liquid flux. I remember seeing these over the place at my work in the early days when I was
doing soldering. You can also get, I remember they also came in kind of metal tins, small metal tins
which you could get your iron into. But none of that is really necessary for the home user. You just need
you just need multi-core flux impregnated solder and I guess that most of the solder you get these
days in the shops will be multi-core flux impregnated solder. Now the thing about that is that when
you apply solder to the tip of the iron the flux very quickly burns off and less than 20 seconds
it's burned off and then it's useless again. So you've only got 20 seconds it will probably
really you should you've only got a few seconds to tidy the truth. Okay first of all make sure
the soldering sponge is wet and basically just run it under that till it's soaked through and then
ring it tight and it really shouldn't be jipping with water in like just sort of damp really I guess
you know ring it out reasonably tight and then place it in the soldering stand. So right there are
six steps to soldering and it really doesn't matter what kind of soldering job you're doing whether
you're attaching wire onto circuit board or attaching two pieces of wire or perhaps if I think I can
want it onto circuit board the six steps are exactly the same. So step one is you add a tiny bit
of solder onto the tip of your iron. Step two wipe it off on the sponge. Step three add another tiny
bit of solder onto the tip. Step four apply the soldering iron tip to the joint you're trying to make
wait a few seconds till the joint starts to melt and then keep adding wee pieces of small bits of
solder until you think you've got enough but the important thing is that once you add the last
piece of solder to the joint you really once the moment you take the solder away from the joint
you really should try to take the soldering iron away from the joint maybe another two or three
seconds after you've removed the solder. So you always add a little bit of solder, take solder away
and then within a second or two remove the soldering iron because the flux in the joint will
will be burnt off and prevent you from creating a good quality joint and that's the main reason why
you end up with see a dull joint or a lumpy joint or something like that is because there was no
flux all burnt away and if you find that that's happened all you need to do is heat the joint up
again add another bit of solder and within a second or so remove the soldering iron before that
flux burns off. It's amazing how little solder you actually need to freshen a joint up.
Just a small amount is all that is required to freshen that joint if it is a indeed a bad joint
obviously you can go you can go madden have a big blobby joint but at least your big blobby joint
will be cleaning shiny and not dull and spiky. Also when you take the soldering iron away from the
joint you want to do fairly quickly because if you do it too slowly again it can pull spikes off
the joint but it's far less likely if you follow the guide that you apply the last bit of solder
and then fairly quickly take the soldering iron away within a second or so off of the last
piece of solder that you add. So you can keep repeating this as much as you like until you get a good
joint and until you get the required amount of solder on a joint I should say it's when you
you linger on the joint and you haven't put any fresh solder on that you end up with lumpy
dull joints. That's basically the secret.
Telesrics extent confidence helps but much less than you would think and you know when you take
the soldering iron away from the joint I know you should do it reasonably quickly you know
you don't have to fly away from the joint but you certainly don't want to take away very slowly
or you end up with lumps.
okay the first thing we need to do is remove a wire from a circuit board and I've just
basically attached a piece of wire to a piece of a perth board which is or a bread board
whatever you want to call it. It's basically just a couple of strips that run in one direction
with gaps between the strips and holds obviously for the components to fit through from the top.
So we basically take that out step one and wipe it on the apply a little bit of solder first of
all to this soldering tip wipe it in the soldering sponge apply another piece of solder to the tip
okay heat the joint remove this wire apply a little bit of solder to the to the joint and remove
the soldering iron here you go and obviously put the soldering iron back in its stand
that's produced a good good joint there. So the soldering iron stays on the joint the whole time
it's the last thing to be removed and as I say really it should be removed within a second or so
if you're removing the solder from the joint. Obviously you can take as long as you like heating
the joint other than you may destroy the component if it gets too hot and you may lift the copper
track from the circuit board if it gets too hot that's the other danger of course but other than
that you know it's not a race the only thing you have to be quick with is that you take the
soldering iron away from the solder joint within a second or so for removing the solder okay so
that's removing a wire from a circuit board to attach a wire to the circuit board it's the same
sort of process you basically wipe the soldering iron apply a little bit of solder to the tip
okay heat the joint place the sold place the wire onto the joint place the iron maybe on top of
the the wire to hold it in place play a little bit of fresh solder to the joint hold the wire
and take the soldering iron away and there you go a fresh joint you really should avoid if you
can it looks not always possible to you know some people create a joint by applying quite a bit
of solder to the soldering iron and heating the joint up and it kind of flows onto the joint and
taking away the trouble with that is that by the time the solder flows down the joint a lot of
the flux can be burnt off the joint and hence you take it away I end up with a joint that's either
dull or lumpy or whatever I guess if you do cooking if you can almost get away with that and
sometimes you have to do it because you you know you haven't got to have hands to hold everything
in place when you're applying the solder but when you're doing it that way which is not the
best way to do it then you've really got to be quick quick because obviously you know you put the
solder on the soldering tip it's burning away and then you put it onto the joint and then
and it heats up and it's still all burning away and then you apply the the wire into the joint
and it's still burning away then finally you take the soldering iron away by this point it's been
sitting on the on the joint and iron for you know several seconds maybe even longer
right so that's why I attached to the circuit board I'll just take that joint back off again
heat it up okay we've got to apply a little bit of fresh solder to the joint take it off
wipe that and the tip should always stay clean you should always be working with a clean shiny tip
on your iron okay so let's imagine we're going to join two pieces of wire together
I've got one piece of wire here and second piece here now I guess usually you'd be working with
multi core wire as opposed to single strand wire which is quite rigid and if it's multi strand
and it's probably worthwhile then turning the wire before you attach the two pieces together
so I'll just turn this piece of wire and how you do that is you basically hang it over the edge of your
desk and pick up your soldering iron and add a bit of solder to your soldering tip of course
okay wipe it off add a bit more solder to the tip hold the wire with your in the x-finger
start the back of the joint and heat the wire up with the solder now after a few seconds
apply a little bit of solder and with the solder and the solder now tip to follow it along the
hole into the wire until you get to the end and that'll coat the whole wire and then take both away
let's wipe the soldering iron clean again put it back in the stand and that then coats the wire
tins it coats it in solder so that when you're trying to work with a thing it doesn't all
split out and get a bit of a mess now I tend to make a 90 degree bend on the bare wire end
on both pieces of wire do that with this one and with that one okay two 90 degree bends in the wire
then I push and I sit one on top one top the other and then I rotate both in opposite directions to
to kind of lock the two together and then it perhaps give it a wee twist just to bind the two
together twist the two pieces to two pieces of wire together okay hang over the edge of the desk
like last time so you've got a mechanical you should really always try and get a mechanical joint
before you solder so obviously by twisting them together you've got this mechanical joint
get the soldering iron out about wipe play a bit of solder do the tip
finger on the wire and apply a little bit heat to the joint like some fresh solder
remove the soldering iron clean the tip of the soldering iron back in the stand and there we have
it a clean tidy joint now you may find you know that you've got some loose ends from that but
you from the piece you folded over you can trim these with your wire cutters if you like
just do that now there we go of course I forgot to mention heat shrink slaring and you know you're
often making up a cable and you'll attach the wires or whatever and you think ah where's the
heat shrink and you forgot to put it on so then you've been done soldering all again then
put the heat shrink on and then resolder it so remember to put the heat shrink on first
in place slide it over the joint if you've got heat gun use that if not use the old toaster technique
that I mentioned in the previous episode unfortunately I don't have a toaster here to hand to
demonstrate that okay so that's joined two pieces of wire together we're going to try soldering
a resistor untrust onto the printed circuit board or piece of per board that I've got here
so turn the per board over so you so that it's on the the non copper side
uh sit it on the board so you can work out where the uh where you need to put the uh the legs through
and try and set the component kind of halfway between the two holes that needs to pass down through
keeps it nice and neat and then what I like to do is I take my small nose pliers I've got here
and just go back a little bit from the hole that I'm looking for grip it and bend it
bend the one leg 90 degrees down okay so that's one leg bent 90 degrees then I can place that
into one of the holes in this circuit board to check that it sits okay then have a then have a
look to see where the second hole is going to be and remember you've already lined up halfway so it
should be quite equally spaced so again I'm going to put my uh small nose pliers just before the
hole grip it take the component out again and bend it again through 90 degrees that's it and now
the component has got nice two neat bends in it I mean you don't need to do that you can just
pass it through and pull it through but you end up with a need to job if you do it this way
and in place the component back into the two holes that you previously had it in
you should line up hopefully now of course you're you're kind of running out of hands
here to hold the component in place while soldering it and you so what you can do is I'm holding
the board in one hand and using my index finger to hold the resistor in place turn the board over
left the end of the solder up so that I can put a little bit of solder onto the tip of the iron
take the iron out at the stand and apply a little bit of solder to the tip
wipe it off find another fresh bit of solder onto the tip a bit more of this time and
heat up one of the joints where the resistor is for a few seconds
and take it away now you'll find you'll have made probably a rather
message joint there it's just been what they're called tacked on but that doesn't matter because
it now holds the component in place and now I like the solder for soldering iron okay now that
is held in place I can take my solder take my soldering iron take it out the stand wipe it
apply a little bit of solder to the tip wipe it off apply some fresh solder go to the other end
of the of the resistor apply the tip between the track and the leg of the component
so he's heating both things up and after a few seconds apply a bit heat on the other side of
this the leg keep applying wee bits at a time all the time holding the solder now on the joint
when you think you've got enough take the solder away and remove the iron wipe the iron clean
back in the stand so as I say you can keep adding wee dabs of solder if you like as as you keep
the iron on the joint the whole time until you see you think you've got enough solder and
bone thing as you take the iron away last and you do it within a few seconds of adding the last
bit of solder I can't stress that enough really okay so we'll just cut the top of this leg off
okay and the first joint that you made it's actually a lumpy and a bit well lumpy and messy it
doesn't have enough solder on it and we can fix that so take the soldering iron out
wipe the tip wipe wee bit of solder wipe the tip some more fresh solder on the tip
onto the joint that was messy first joint keep it up a few seconds add a wee bit of solder
a wee bit more solder that seems to be enough take the iron away
and that's produced a nice tidy clean joint I'll just cut the end off the component and that's it
and really that's all there is to the soldering it's it's far less about skilding you would think
it's just down to the fact you have to have flux on the joint and there's more than enough flux
and in multi core solder to do that you know you don't need bottles of flux as I say there
or anything like that you must take the soldering iron away from the joint
within a few seconds of adding the last piece of solder that's the most important thing of all
well I don't know how this is worked and I may have rambled a hell of a lot to hope you enjoyed it
and they'll give soldering a go it's the sort of thing you don't do very often probably but
it's certainly a very handy skill to have show notes for this podcast are available at HPR
with a list of relevant links and further information I can be contacted at mrx at hpr at googlemail.com
that's mrx at hpr the at symbol googlemail.com so until next time thank you and goodbye
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