Lead/Lead-free soldering with Rosin Flux

[jonathanwilcox]

Hi, guys, I have some questions regarding soldering:

why does my solder iron still have black stuff on the end after I wipe it on a wet sponge to clean?
 

what is the best soldering iron temperature to use on lead-free solder/lead solder? I'm also cautious of also overheating the wire (mine goes up to 350 degrees)

Is it better to have the soldering iron on a high heat for short time or medium lower heat for a longer time?

is it best to use lead solder with flux as some flux's don't have a high melting point causing char and oxidise? Alternatively, what is the right flux when working with lead-free solder?

how does charring reduce heat transfer?

Lastly, what size solder wire should I use for electronics?

If anyone could take time out of their Sunday to answer my annoying questions I would be forever grateful! 

Cheers, Jonathan

 

[apprentice87]

I think you are MASSIVELY over thinking this...

Just get an ordinary soldering iron, plug it in and let it get hot, never mind worrying about temperature. Forget wet sponges, where you get that idea?? Just very quickly dip the end of the iron in the flux and then wipe it with a dry cloth. Use flux cored lead solder. Tin the thing you want to solder first. Then just heat it up with the iron and if you need to add more solder. Use what ever size wire you prefer.. Thicker and you only use a little bit, [but it can be clumsy] thinner and you need to stuff more in.. I generally use 0.7mm or 1.2mm thick, not at all critical though, just a matter of preference..

I always use proper lead solder.. It was designed and perfected over hundreds of years, so it is good enough for me. The modern stuff is lettuced, just like everything else modern..

This is more or less the idea, only i ALWAYS tin the wires first but i suppose it is personal preference..





john..

 

[Tony S]

Lead free solder can become crystallised and therefore prone to failure, I wouldn’t use it.

 

[apprentice87]

There you go!!! I think it is total lettuced too, same with sweating copper pipes, the proper lead solder is the way to go..

I do not know what you think, but as far as i am concerned all this stuff about lead pipes for water is total lettuced too. How long before they decide/admit that chemicals in the plastic pipe are harmful.. [as in clingfilm microwaves etc]

Funnily enough, i do seem to remember that you have to be careful with the plastic pipes, as contaminating substances in the ground can penetrate them and contaminate the water. Yeah, great idea..

john..

 

[Tony S]

Many moons ago I did a fair amount of plumbing. Initially using Yorkshire fittings until I came across Delcop end feed fittings, then I could use whatever flux/solder I wanted.

Cable jointing I used tinmans solder with pure rosin (fossilised amber) as the flux.

 

[kerching]

And don't forget that the sell by date on bottles of water that have taken 9 zillion years to be filtered throughECs thong gusset volcanic rock is only due to,the chemicals leaching through from the container/bottle 

 

[roys]

 I use 22 swg lead multicored solder for electronics with an old non temp controlled pencil Antex soldering iron, works a treat.

I just usually give the iron tip a quick dry wipe whenever the solder loses it shine so usually every new joint if there is any time gap, so after every time it comes out of the stand it gets a wipe and a fresh bit of solder applied.

I realise some stands have the wet sponge space but mine doesn't so I have not done the wet sponge bit and I have been soldering for 40 years.

Be careful if buying solder from eBay some of them are suspect quality with a lot of impurities apparently.

I buy mine from RS but any of that type of supplier I imagine will be fine.

For beginners "bigclive" on YouTube does a good beginners video.

 

[apprentice87]

And don't forget that the sell by date on bottles of water that have taken 9 zillion years to be filtered throughECs thong gusset volcanic rock is only due to,the chemicals leaching through from the container/bottle 

Never thought of that...

john..

 

[Blue Duck]

Would the exp be infinite if the container were glass???

Sick of all this plastic lettuced as well as all this cheap **** from Shenzhen.

-_-

 

[Bruspark]

350c for lead solder 380c for lead free seems to work for me

Work as fast as possible while still getting a fully melted joint.   Don't disturb the joint until you see it 'set'  then blow to cool it.

Solder no wider than the joint you plan to make !    I have all sorts of widths in my tin  but usually around 1mm gets most use.

for cleaning a Wet sponge and hot iron always works for me  - if not you've got something sticky on the bit or its worn through.

We are told that lead and lead free solder don't mix well so use the horrible lead free to repair recent stuff and leaded solder for all else. 

Use additional 'no clean' spray on or pen flux fluid on surface mounted component joints - then use a little flux cored solder too there and elsewhere.  Plumbers flux is NOT the right thing !!!!

Ignore anything plumbers tell you about soldering.  It is the same idea but actually very different.

If you are new to this practice on any old boards/radios etc you can get your hands on before you try it 'for real'

I've about got it now . .  40 years on . . 

 

[jonathanwilcox]

Hey Bruspark, 

thanks so much. What happens if you use plumbers flux?

whats better out of no clean spray and pen flux? Can you use isopropyl alcohol too?

my iron even gets blackened when I wipe it clean and when I put solde on the tip it seems to corrode also. Does this mean my tip is too hot? 

Do you have a particular brand of solder which is good? 

Cheers,

Jonathan

 

[Geoff1946]

Plumbing flux leaves nasty residues which are best washed away with water. Not easily done with electronics. Old fashioned lead/tin cored solder is definitely easiest to use as well as cheaper than lead free but anything you buy now will be made with lead free.  The two will mix, (I've done it!) but there are theories that mixing is a bad idea for some complex metallurgical reasons.

 

[kerching]

Never had any issues

tip,goes black....clean it back to copper.....re-tin it....carry on

i quite often use a gas Portaso at work.....that even comes with a little sponge in a tin. Keep it wet and wipe the tip 

failing that

get an apprentice

kick him in the 'nads

when he gasps for breath wipe soldering iron tip on his tongue  

just soldering on

 

[Badger]

Here's a question which people on here uses temperature controlled iron stations and who uses the standard none controller irons that heat to a standard temperature I have a temp controlled station which is good because you can make the temp higher or lower depending what your doing with the soldering work 

 

[Badger]

View attachment 9219

 

[Andy™]

i did have a temp controlled one. the controller died so i just fitted a plug on the end of the irons flex. few years later and it still works

 

[Badger]

View attachment 9220

I think the iron I've bought is a 24volt unit 

 

[apprentice87]

Bloody hell!! That all looks good!!!!

john..

 

[Badger]

Is that to mine or Andy's post :-|

 

[Andy™]

Is that to mine or Andy's post :-|

well since i didnt post any pics, id say yours