Newbie soldering questions

[tbeck]

I would like to begin practicing soldering in order to become proficient enough to MIDIfy my Rodgers 830 console. It is already MIDIfied but something has gone wrong internally and I think it will be better in the long run to start from scratch.

I have never used a soldering iron before. I've checked out some resources online and watched some videos but I still have some questions from you real-life experts.

I have purchased the following equipment:
Weller 40 watt non-adjustable soldering iron with a chisel tip and a conical tip
Solder stand with sponge
Kester 0.31" 60/40 rosin core solder
3rd hand
solder wick and pump
Wire stripper
Wire cutter

Before I begin I have some questions. Maybe a dumb one or two.

Regarding lead fumes. Do any of you take precautions with the fumes? Do you use an extractor? Does a large room with ceiling fans provide a sufficient margin of safety? Are concerns about lead fumes overblown in the first place?

Do I need to tin the tip of the soldering iron before first use? I have seen some videos where the tip is spread with flux and then wrapped in solder and allowed to heat up? Some advise tinning the tip frequently during a soldering session?

Which tip is better for soldering small gauge wires: chisel or conical?

Any ideas for best practices? For learning and practicing?

I'm really hoping I can get good enough at this to carry out my project.

Tom

[lizny]

Fun times! I'm not the expert but am much of the way through a big midi project, and had some modest experience beforehand.

You need a multimeter, this will let you confirm each of your soldered connections is good, and also that you haven't shorted anything.

I keep tinning a bit as I go, the parts heat much faster, I notice if the tin is rubbed off. I like my chisel tip, I think it works better than the pointy one but your mileage may vary.

As I understand it, lead melts at soldering temperatures, it does not vaporize. Think of the difference between turning an ice cube to water and turning it to steam. The fumes are just the flux, so pretty much you are breathing incense. You still don't want to suck in a lot of the stuff unnecessarily. I keep a window open and use a small fan with a carbon filter to suck fumes away. You do want to wash your hands carefully when you are done and don't stick your fingers in your mouth while working.

Maybe pick up an electronics kit and build something nifty for practice. There are lots of youtube videos, I like Adafruit's.

[tbeck]

Thanks, Liz. I like Adafruit as well. I do have a multimeter as well. I suppose that I should begin practicing with wire, rather pads on a board?

[Admin]

Personally, I wouldn't worry about lead fumes. Solder fumes are mostly from the rosin core. I suppose, if you were soldering eight hours straight per day, seven days per week, and under twenty years of age, there might be some concern, but you're not going to be doing that, are you? Regardless, it's too late for me. I've been soldering since I was eight.

The tip of your iron should be tinned prior to every use. Let the tip reach operating temperature, then touch solder to the tip forming a blob around the entire tip, then wipe the excess off using the damp sponge. The tip should be bright and shiny. Repeat as needed to keep it this way while soldering.

Back in the day when I soldering tube sockets, I preferred using a chisel tip because of its greater surface area; however, a chisel tip is too big for most circuit board work, so today I mostly use a conical tip. If you're looking for a rule of thumb, use a tip that is no larger than the joint your are soldering.

On related subject, a 40 watt iron might to be too hot for circuit board work, but should be fine for larger contact surfaces. If you'll be using the iron to solder circuit board wires and components, wipe the tip with the sponge more frequently to prevent it from becoming too hot and damaging the board traces.

Finally, the number one rule in soldering is apply the solder to the joint, not the tip of the iron. Heat the joint with the iron and touch the solder to the joint. Continue heating the joint with iron until the solder has flowed.

[j reimer]

Just a couple of things to mention (or underline) in addition to the excellent advice already given. The main role of the soldering iron is to bring the two surfaces to be joined, up to the correct temperature. It needs to be in good contact with both surfaces. And yes, the solder is applied to the surfaces. It will melt onto them if they are hot enough. A little solder on the iron tip is to enhance that contact with the surfaces. And beware of any movement before the joint is cool enough.
Secondly, and quite separately, it is bad practice to depend on the soldered joint to keep a wire, for example, effectively anchored, especially where any movement or vibration is possible. There should be additional anchoring - at the very least, in how the wire leaves the wiring harness.

[ChristopherDB113]

Just from experience, I will throw in some unsolicited advice:

It always takes the soldering iron longer to heat up than you think so plug it in a few minutes before you plan to start. Then once it heats up, use some fine sandpaper, maybe 150 grit, to brush off any old solder and get the tip nice and clean. Clean it off periodically during the job too.

[Admin]

Then once it heats up, use some fine sandpaper, maybe 150 grit, to brush off any old solder and get the tip nice and clean. Clean it off periodically during the job too.

Personally, I would not use sandpaper on a plated tip, which most are nowadays, as it could damage the plating. This article pretty much covers the care and feeding of your iron's tip.

[ChristopherDB113]

Thanks for the tip, no pun intended. My soldering iron is an old cheap one, and I doubt the tip is coated. There is also the possibility that it was coated but I have sanded all that coating off over the years. Either way, it still works for me.

[tbeck]

Thanks for the advice, everyone. I'll give it a go and report back.

[toodles]

Definitely use a plated tip and do not sand it. Use a damp sponge to clean off any residue on the tip once it is heated.

[jbird604]

I use a tip cleaner that looks like a little metal ashtray with a metal pot scrubber tucked inside. Not sure where it came from, but every few months I replace the metal scrubber thing to keep it fresh. Jabbing the tip into that mass of wirey metal cleans it instantly when it's hot, removes and sequesters the black gunk that can build up on your tip as you work. I suppose a pad of very coarse steel wool would be just as effective, maybe even better, in place of the pot scrubber.

All the advice given above is awesome. Wish someone had told me 50 years ago about getting the pieces to be joined hot enough to melt solder. I've wasted years of my life going back over solder joints that failed because I just melted some solder and let it dribble on the spot I wanted to join!

[Organfella]

Slightly off-topic - anybody old enough to remember those old copper headed soldering irons that needed to be heated up over a kerosene blow torch? Those blobby copper heads would stay hot enough for a long time to solder seams on tin cans, iron bathtubs and buckets. The solder came in bars about half an inch square and a foot long with solder paste in flat round tins. I think I still have one of those irons and half a bar of solder somewhere....
Nico

[tpappano]

Oh yeah, I've used them!

[tbeck]

Soldering is harder than it looks. I'm obviously doing something wrong.
I can't even tin the tip. I wait several minutes and then tough the solder to the tip. There is a lot of smoke, but instead of leaving a shiny residue, it just looks scorched. If I keep the solder on the tip, it eventually sort of forms a blob and when I go to clean off the "excess" on a damp sponge it all comes off.

I twisted some stranded wires together to see if I could solder them, but no matter how long I hold the tip to the wire, it never heats up enough to melt the solder that I'm touching to the wire (not the tip).

Any ideas or suggestions?

[lizny]

I'd say work on the first problem - not having a good tinning absolutely affects heat transfer.
Colin tins here at about 1:45, you can see up close: https://www.youtube.com/watch?v=QKbJ...ature=youtu.be

[tbeck]

It's a 40 watt iron, non-adjustable. If it gets too hot then how can it be usable?

[you795a]

I was thinking that maybe it was a much larger wattage soldering iron. The 40 watt should be fine.

[tpappano]

Might I ask, what is the exact model numbers of your iron and tips. I do production soldering and my workhorse iron is the Ungar/Cooper/Weller 47 watt element with the 1/8” iron plated chisel point tips. These things have been around forever. This particular setup can can “lose its tin” if allowed to sit idle because the temperature rises when it's not heating joints and the solder coating the tip will oxidize, necessitating re-tinning. I normally brush junk off the tip with a scrap of paper towel. One can rig up a switch with a diode to reduce the voltage to the iron during ‘standby', which will extend the tip life and help the tip hold its tin. Depending on the exact model, some irons will idle at much higher temperatures than others, confounding the tinning situation 8)

[quantum]

Wires can act like a heat sink, drawing the heat away from the joint. Also the vice or clamp you use to hold the work piece can also act as a heat sink. When at all possible, I like to apply the iron tip underneath the joint so heat rises into it. Stranded wires can act as a wick, so if you are applying solder and it tends to disappear, it might be being drawn into part of the wire still covered by insulation. If stranded wires are giving you problems, try tinning the tips of each individual wire before soldering the joint.

[tpappano]

Another tip, as you bring the tip in contact with the joint apply a small amount of solder to the tip to help transfer heat to the joint, then when the joint is heated, add the rest of the solder to finish it. This whole process normally will go pretty quick.

[Organfella]

Something I might add - if someone already said this I missed it: The two or more ends that need to be attached by soldering need to be as steady as possible. Hand-held efforts is asking for trouble and make the job more difficult with wires bouncing around and losing contact when trying to heat and apply solder with the remaining hand. Some clamping device to secure the parts to be attached will ease and speed up the process considerably besides freeing the usefulness of that vital extra hand.
Nico

[tbeck]

Thanks for the suggestions everyone. I think my problems start from trying to tin the tip. I heat up the iron for a few minutes and then when I touch the solder just seems to burn away. There ends up being sort of one glob on one side, but it isn't very shiny. Also, the solder is used up very fast.

I'm trying to upload a couple of pictures, but I'm unable to for some reason. I'll ask admin about it.

In any case, it looks like the tip is already oxidized. The iron has only been on for no more than 10 minutes. I'll post the pictures when I can.