Lead or lead free?

[Alex SE]

Well, there are 2 decks waiting for some fixing and adjusting but I'm just feeling myself too lazy and keep telling to myself "next week" under the last 3 or maybe little longer...
However, not so lazy to think and two things/questions just came up:

1. How many watts is needed for some minor soldering. Planning to re-flow my soldering station since that there is a cold joint somewhere. Was thinking to buy some simple solder pen. Price is about the same for 30W and 60W, but I would rather go for 30W, don't want to apply unnecessary heat to a PCB. You think that 30W is enough?

2. Just found out that soldering wire I'm using is leaded. It is one of better soldering wires on the market Warton metals AutoSol 62S with 2% silver and flux core. Wondering, how "dangerous" lead actually is? I mean, surely is for someone who is soldering 8 hours a day, but to solder some resistor here and there?! What are you using, do you care about lead/lead-free?



BTW, what does "Rem" means?

 

[J!m]

REM is remainder.

The 63/37 rosin core is what I use “eutectic” they call it.

 

[8991XJ]

Rem is Remainder. Add up what is specified and subtract from 100, that is the remainder.

I like 62/36/2 silver solder. This seems to be what you are using. It is eutectic which means it melts and freezes at one temp and remains shiny.

30W should be fine. Need 60w if you have a big chunk of copper you are trying to heat to accept solder.

 

[Alex SE]

Thanx for answers, I got it, nothing to worry about that sw. Should just change a STTC-138 (412°C/773°F) tip to STTC-538 (302°C/575°F) but that's another 50€/$ cost not on priority list for a moment.

30W it's gonna be then

 

[mr_rye89]

I only use lead/tin solder, lead free is crap. Also a 40 watt iron is good to have, just heatsink as you need to and don't leave it on the joint too long. I also use a 140 watt iron (gun) for big stuff like the PEM nuts on the White Oak PL backplane boards, copper buss bars, etc

 

[20tajk7]

60/40 & 63/37 are the best for electronics.
Lead free melts at higher temperature, 230°C instead of 180°C which is not good for fragile components, it never got shiny so you can't see if your soldering is good.
Some lead free solder has solvent that contains really bad chemicals that are worst than lead.

 

[Alex SE]

In that time I got my soldering station MX-500P-21 (which is a way too good for someone like me) and solder wire I wasn't even know that there is different kinds of solder wire. It was more like "this one is a better one, it has a solder paste inside" Same thing with a soldering station, I was thinking "this have to be a good one, a whole electronic factory is using that model". Temperature? What about that? Aren't all soldering tools have the same? I meant, tin and melting it, there is no science about it. First a couple years later, when I started to using it and visiting different forums, have learned some things.

 

[WOPL Sniffer]

Lead free is junk, toss it.
30W iron is pretty small.

 

[vince666]

i use the classic eutectic lead/tin with resin core and a JBC 25W iron and i feel just OK.

about the lead, regardless of how much you are soldering, don't forget to wash your hands carefully after soldering.

just fyi, an "eutectic" alloy is an alloy which melts at lower temp than the individual (pure) metals, just that.
in fact the eutectic lead/tin melts at lower temp than pure lead and pure tin.

 

[markthefixer]

Wattage of an iron is how fast the heat can flow in,

since an iron for pcb work should be a temperature controlled iron anyway, the heat input is cut off once the temperature is reached-
so 60 watts just addresses the maximum size of the solder joint (and it's heat loss) that it can pump heat into to try to hit the soldering temperature.

you do want it to be quick, for fast soldering times, rather than sitting on a joint for 5 to 10 seconds cooking it before it hits soldering temperature.

 

[wattsabundant]

The worst thing you can do is have a bowl of chips nearby while soldering. Solder, munch. Solder, munch and ingest the lead.

 

[J!m]

The Romans used lead powder as seasoning.

That wasn’t so bad, was it?

 

[8991XJ]

MTF has the key comment about the iron. Temperature Controlled with tip temp sensor to control the heat, on or off. When the tip is put on the work and heat is pulled out this type of iron turns on and keeps the temp to the controlled setting and then switches off. They cost more but work way better. They are available in both station and just as an iron and some have set operating temps.

Other options are Variable Temperature station or the Fixed Wattage iron which both supply constant wattage with the variable being adjustable with a knob. These both can have the heat sucked out of the tip when first put on a larger piece of work and one must wait for the fixed wattage to catch up with the heat pulled out of the tip. This type has wide swings in temp as the tip is in contact or not with the work depending on how much the work acts like a heat sink.

 

[Alex SE]

Bought today a 30W s.c. solder iron. Anyone who have worked with some serious soldering station will declare it as a joke. It will do the job but definitely not for fine electronics. It's first now I really appreciate my Metcal which is btw fixed now.

 

[8991XJ]

I've read Metcals are good ones. I had a pencil, got a variable temp station then finally a Weller temp controlled. Much more fun to use.