Author Topic: Correct temperature hand soldering? (Read 13424 times)

NiHaoMike · « **Reply #1 on:** February 04, 2014, 02:22:03 am »

I usually leave it set to 300C for general work using leaded solder. I sometimes have to bump it up to 350C for large connections or lead free solder.

jwm · « **Reply #2 on:** February 04, 2014, 02:52:01 am »

I learned I was soldering for a long time at too low of a temperature for the flux core to fully activate, I went back to my old projects and reflowed all the joints and saw the very satisfying fizzle of the flux and admired the new joints with proper meniscus. Now I do 350C and have given up on lead free. I don't know what sort of flux core they use, but I feel nausious after using lead free solder but have never had an issue with leaded solder.

If your joints are smooth with a gently concave (not! convex or roundish) shape and you can see the flux activating then you are probably okay. adafruit has some pictures showing what 'cold joints' look like when you have it hot enough to melt the solder but not hot enough to properly wet the pins.

http://learn.adafruit.com/adafruit-guide-excellent-soldering/common-problems

IanB · « **Reply #3 on:** February 04, 2014, 02:57:08 am »

650 F/350 C seems good to me for leaded solder. It's hot enough for the flux to be fully activated, but not so hot as to burn the flux and leave an ugly mess on the tip.

jeremy · « **Reply #4 on:** February 04, 2014, 03:03:35 am »

I use 375C with a lead free solder from Nihon Superior, works beautifully. If I need to do a large joint I just switch to a higher wattage iron.

Fsck · « **Reply #5 on:** February 04, 2014, 03:03:44 am »

When I use my Metcal, I just use the 700 series tips. When I used a JBC (the few times) with C245s I usually set for 675. When I primarily used my Hakko 936, I almost always just left it at 700F as well. Technically, I should be fine with the 600 series tips, but it just seems like so much extra work having to keep more tips around for low thermal mass targets and to keep 700s around for larger thermal mass targets.

I'd probably be more drawn to 600 series tips if there was a cheap (used) Metcal/Thermtronics with more output capacity. 80W might be nice but I'm kind of curious to know what would happen if there was a 150W unit. (My STSS puts out 40W)

orion242 · « **Reply #6 on:** February 04, 2014, 03:52:17 am »

Maybe I'm just clueless but I usually start at 450-550F (leaded solder) and only move to 550-650F if its something large that is sucking the heat out of my iron. Leaving it at 550F+ really seems to foul my tips if I leave it sit for more than a few minutes. Lead free stuff always seems to require more heat, unless I mix in lead. At 650F+, it seems I really need to be quick with SMD pads or they will start to lift off occasionally. Fouling out the tip also seem to only take a few minutes at best before I need to dip it in flux and re-tin.

Do I just have a tip at the end of its life or do you need to constantly use/clean the iron at these high temps?

jwm · « **Reply #7 on:** February 04, 2014, 04:28:14 am »

Quote from: orion242 on February 04, 2014, 03:52:17 am

Maybe I'm just clueless but I usually start at 450-550F (leaded solder) and only move to 550-650F if its something large that is sucking the heat out of my iron. Leaving it at 550F+ really seems to foul my tips if I leave it sit for more than a few minutes. Lead free stuff always seems to require more heat, unless I mix in lead. At 650F+, it seems I really need to be quick with SMD pads or they will start to lift off occasionally. Fouling out the tip also seem to only take a few minutes at best before I need to dip it in flux and re-tin.

Do I just have a tip at the end of its life or do you need to constantly use/clean the iron at these high temps?

That seems really low to be able to create solid joints or even barely melt solder. are you sure your soldering iron is reporting its temperature in F and not C? from what you say it sounds more like 450C than 450F. And yes... I made this mistake for a bit... and had set my new soldering iron for 650C rather than 650F and was wondering why my new tool was acting less like a soldering iron and more like a magic PCB pad remover.

I have never ruined or EOLed a tip under normal usage. I do re-tin and wipe the tip (used to use wet sponge but now use brass wool) every 20 leads or so which doesn't seem excessive.

John

IanB · « **Reply #8 on:** February 04, 2014, 04:31:35 am »

I think it's normal to need to wipe the tip clean and re-tin it every few minutes. The tip is hot and the solder will oxidize.

I haven't tried SMD soldering, I've only soldered wires, terminals and through hole. However, I wouldn't think the iron should be in contact for more than half a second for SMD terminals. It's a case of a momentary "touch" and you are done.

VK5RC · « **Reply #9 on:** February 04, 2014, 04:57:24 am »

I have always used 350c for leaded solder, higher if I have to use lead free, which I try and avoid, an old ham friend said heat 1st, then apply solder, then wait a bit for the flux to do its stuff (quite a bit evaporates). No different for smd.

jeremy · « **Reply #10 on:** February 04, 2014, 11:19:42 am »

I almost exclusively do SMD nowadays. Just to elaborate further, I use a weller WMRP with a micro chisel tip (about 2mm I think). 375 is more than enough for the lead free I use, I can even do 350 pretty easily if I am worried about the components. All SMD joints take less than one second, I can even do the whole side of a small tqfp in about one second. I always apply extra flux and clean my iron with tip cleaner (just solder with a very active flux) as soon as it seems like solder is not wetting the tip of the iron. This probably ends up being every 10-15 joints. I also don't use a wet sponge but rather flux coated brass wool as it doesn't shock the tip like water does and cause the solder to harden instead of being removed.

Temperature isn't everything; if your iron doesn't have good temperature control and power, it could droop significantly lower than your set point on a board with high thermal mass (aka big ground plane). Also if you have a bad thermal connection because of tip oxidation or wrong tip choice (trying to solder big stuff with little tips) then it will take longer again.

Dago · « **Reply #11 on:** February 04, 2014, 11:20:13 am »

My JBC station came with a 350C preset and I have literally never touched it. Not even tried to change it. Works beautifully...

Rerouter · « **Reply #12 on:** February 04, 2014, 11:47:30 am »

330 is the norm at my work (9** model hakko clone)

though as they are lacking the wattage of my home iron I fairly commonly ramp it up to 450 for a minute to dump the heat into planes and other sizable components

Psi · « **Reply #13 on:** February 04, 2014, 11:57:48 am »

300C pretty much the lowest you can effectively solder at but the joints usually don't come out very good/shiny, so i wouldn't recommend it.

330C for small SMD or tinning small wires (so the insulation doesn't melt/shrink)

350C for general soldering

390C for heavy duty soldering

450C for getting TH stuff out of multilayer PCB groundplanes (quickly change back under 400C when done as 450C will damage your tip quickly)

dexters_lab · « **Reply #14 on:** February 04, 2014, 01:06:14 pm »

hmm, looks like i'm using my station just like everyone else, typically using 330-350 for 99% of what i do.

i think now i will just put the lid back on my station and leave it alone!

GreyWoolfe · « **Reply #15 on:** February 04, 2014, 01:21:31 pm »

I typically solder at 700F.

WarSim · « **Reply #16 on:** February 04, 2014, 03:07:03 pm »

I guess I am the odd man out on this subject.
One part of my job, not all dat every day, is repairing PCBs. It is very slow and carful work. I have repaired many boards due to previous repair cooking.
I need to advise, do not use more than 50degC temperature compensation. Use the right tools.
I have never needed to increase more than 80degF to effect a repair. Yes this includes a few custom 18 layer boards, and yes it included distributed ground plane layers.
Using 2 or more heat sources is better than one that is too hot. This is why so many soldering tools are made. Pre heaters, zone heaters, irons, plate adapters, pin adapters, IR lights, tweezers, desolders and ultra sonic tools. (Haven't used Ultra sonic tools yet). They all have a function and purpose. Vastly increasing an irons temp because of not using the right tools is dangerous for components and board.
On the other hand I have worked with many board burners. An endless source of creative excuses.

Often they seem to represent the majority
Of course I am only offering my input from my vast experience, accept it or deny it that is your choice.

Sent from my iPad using Tapatalk

nanofrog · « **Reply #17 on:** February 04, 2014, 05:14:14 pm »

600F/315C most of the time.

zapta · « **Reply #18 on:** February 04, 2014, 05:54:06 pm »

Quote from: wilfred on February 04, 2014, 02:07:40 am

So what temperature do you set? Do you pick one that works? Is there an upper limit. In the former case accurate temperature display isn't necessary, it just has to be precise. In the later case accuracy is important as well as precision.

You are asking the wrong question ;-)

Check this video series (multi part):

Part 1 12:15 "Controlling the tip temperature is not the real problem" ... "in reality, tip temperature is not that critical at all".

nctnico · « **Reply #19 on:** February 04, 2014, 06:24:47 pm »

In my experience 330 deg C works best for leaded and lead free. Most of the problems I see are caused by using a tip which is too small and therefore can't transfer enough heat.

kolonelkadat · « **Reply #20 on:** February 04, 2014, 09:41:12 pm »

Quote from: zapta on February 04, 2014, 05:54:06 pm

video from 1980
Part 1 12:15 "Controlling the tip temperature is not the real problem" ... "in reality, tip temperature is not that critical at all".

I wonder if that's still true 35 years later.

I can't help thinking that pcbs like this one are way more forgiving than modern boards, even if it is just down to a matter of repeatability.

orion242 · « **Reply #21 on:** February 05, 2014, 01:52:30 am »

Quote from: jwm on February 04, 2014, 04:28:14 am

Quote from: orion242 on February 04, 2014, 03:52:17 am
Maybe I'm just clueless but I usually start at 450-550F (leaded solder) and only move to 550-650F if its something large that is sucking the heat out of my iron. Leaving it at 550F+ really seems to foul my tips if I leave it sit for more than a few minutes. Lead free stuff always seems to require more heat, unless I mix in lead. At 650F+, it seems I really need to be quick with SMD pads or they will start to lift off occasionally. Fouling out the tip also seem to only take a few minutes at best before I need to dip it in flux and re-tin.

Do I just have a tip at the end of its life or do you need to constantly use/clean the iron at these high temps?

That seems really low to be able to create solid joints or even barely melt solder. are you sure your soldering iron is reporting its temperature in F and not C? from what you say it sounds more like 450C than 450F. And yes... I made this mistake for a bit... and had set my new soldering iron for 650C rather than 650F and was wondering why my new tool was acting less like a soldering iron and more like a magic PCB pad remover.

I have never ruined or EOLed a tip under normal usage. I do re-tin and wipe the tip (used to use wet sponge but now use brass wool) every 20 leads or so which doesn't seem excessive.

John

I had to double check. My LF-1600 has the units as F on the display but I think your right, its degC or this thing is a mile off.

Maybe the C / F switch only changes the units displayed

scientist · « **Reply #22 on:** February 05, 2014, 09:25:58 am »

Lead free makes me vomit and has ruined several boards / ICs. If you're scared of lead poisoning then wash your hands and don't lick your soldering iron.

jwm · « **Reply #23 on:** February 05, 2014, 10:46:51 am »

Quote from: scientist on February 05, 2014, 09:25:58 am

Lead free makes me vomit and has ruined several boards / ICs. If you're scared of lead poisoning then wash your hands and don't lick your soldering iron.

Yeah, I have seriously felt... dumber... or something after using lead free. Like huffing something bad. It could just be because I am used to the smell of leaded, have been using it since I was 10 or so and built radios with my dad, but I think it is something real and bad about the lead free flux. I can especially feel the difference in my eyes. lead free flux burns and makes my eyes water, leaded flux smells like pinecones. for some reason goggles made it worse as they somehow captured and directed the lead free fumes into my eyes. I made a custom vacuum system to pull the fumes away, will document it soon, but it's still much more of a pain than using leaded solder and only works on my bench.

In any case, RoHS really needs an exception for home/hobby use, or at least say something about how you can't replace the lead with something _more_ toxic that happens to not be on the RoHS list.

I now save my unleaded solder only for parts I am going to handle a lot, like joining copper clad boards for structural PCB or soldering a tin RF shield closed, but not electrical contacts.

grumpydoc · « **Reply #24 on:** February 05, 2014, 11:04:49 am »

I have a small reel of lead-free just incase I need to use it but, so far, I haven't felt a burning desire to so do.

I suppose IF I were repairing something modern enough to be RoHS, and IF I was doing that for a fee, or desiging something new to sell I'd use lead-free but most of the things I open for repair are full of lead solder anyway and the rest are likely to be my own projects or stuff around the house so I can't see the point.


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Author Topic: Correct temperature hand soldering? (Read 13424 times)

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