I understand soldering in general but I can’t figure out how to keep the tip from getting all black and coated. I currently wipe it with a wet sponge constantly but it seems like the tip is actually overheating. Any thoughts would be appreciated. Specifically if there is a way to tin a tip that has been ruined once.
Jesse
Yeah, it will look all black like that.
what I do is - before using the iron (while it is still cool) I’ll use some sandpaper or a file to make the tip kind of shiny.
When it heats up, I apply solder to the tip - thus “tinning” it.
The solder helps with heat transfer between the iron and the work.
I, too, wipe the iron on a wet sponge, and then apply more solder to it to keep it tinned.
I don’t think your tip is ruined. Just touch it up with a file or some sandpaper, heat it up, wipe it off on that sponge, and apply some solder.
Good luck.
Rob
Yup, just sand it down to remove all the blackness (basically, corrosion) (with the iron OFF!). Then plug it in, and as SOON as it is able to melt solder, coat the entire thing. Be careful of spatters and drops while doing this, you’ll make a small puddle of solder. If you let it heat all the way up before tinning, it will be too late and the tip will have already started to blacken. if it’s too far gone, misshapen or pitted, just get a new tip, they usually aren’t expensive. And be sure to tin the new one prior to use.
Radio Shack also sells a small tin of “tip cleaner” which is a good investment. And when soldering, keep the sponge damp and periodically wipe the tip as you put the iron back in the stand.
–Randy
Jesse,
I’ve noticed that the type of solder will also exacerbate or prevent that problem. I find that solders with the flux already added makes for a cleaner solder joint and iron tip. (Kester makes a good solder with those properties.) When I’m soldering small wires (e.g. like a decoder installation), the last thing I really want to fiddle with is having to apply flux.
As Randy suggested, pre-soldering the tip and wiping it off regularly are a must.
Tom
Thanks guys, I hoped the answer would be something around those lines. I have to print this out because I know a lot of people with a similar problem.
Jesse
Good advice from everybody. Tom, you should always use solder with flux in it for electrical and electronic work. Use 60/40 rosin core solder. There should never be a need to apply flux separately for this kind of work. I don’t even find it necessary to use flux when soldering to rails. The flux in the solder is sufficient. Another thing that can build up the black stuff on a tip is letting the iron idle in its stand without being coated with solder. I always re-tin the tip right after I wipe it off.
…Bob
Bob,
I used some solder that I got from Radio Shack and I was a pain to work with. (It was 60/40, as far as I was aware of, but I don’t know if it had solder in it. I assumed it didn’t ) The stuff I’ve used at work is the Kester “44” Rosin core. The tips always remain nice and clean and I’m always able to achieve a nice, shiny solder joint.
Tom
Tom, that’s the same solder I use–Kester 44, 60/40 mix. Solder comes in different mixes (40/60, 60/40 and 63/37), all of which are suitable for electrical and electronic work, but the last two are the most popular. The tin/lead ratio determines the melting temperature (more lead, lower temp.) and the strength. Virtually all the solder that R.S. sells is suitable for electrical work, so I don’t know why you had trouble with that batch (maybe it was coreless), but you certainly can’t go wrong with Kester 44.
…Bob
Kester 44 is what I’ve found to be the best as well. I don’t know where Radio Shack gets their solder from but I’ve had three different sizes and types from RS and they just weren’t as good as the Kester. I use the R-S solder for car weights now!
I use to do a lot of soldering in the electronics business. A couple of tricksI learned:
More info:
Good quality soldering tips are plated to prevent pitting (weller for instance), the minute you take sandpaper or a file to the tip, you destroy the plating. The previous writer had it correct. Damp sponge to take off the oxide and then immediately tin the tip to prevent oxidation.
Solder works by literally disolving a layer of the base metal and mixing with it. It forms an amalgam (like the mercury-silver combination that fills the holes in your teeth) that is chemically bound to the base metals. It is the reason why well done solder joints are often stronger than the materials being joined. This amalgamation also eventually disolves the soldering tip and forms pits and holes in it. Moral of the story, when the tip gets too badly pitted to work well, replace it with a good one, keep it clean with the sponge and tinned with solder.
Never, ever take abrasives to it.
Incidentally, at one point early in my career I taught over 2,000 people how to do high precision soldering. In the February 2002, Classic Toy Trains magazine, I penned an article on soldering track leads.
Myles M.
The advice given so far is fine for small irons and electronic work. By the way, 63/37 has the lowest melting temperature of the solders mentioned. I typically get sizable spools (up to 1 pound) of rosin core solder at an electronics supply house and you’ll have solder to last a LONG time. If you have a good quality solder station with the little sponge provided, get some spare sponges as well – you’ll eventually need to replace the original.
IF you do heavy duty soldering (10 gauge bus wires, heavy rail, and large pieces of brass strip and bar stock), you may need to refine the techniques listed. My big iron (nicknamed “solder beast”) is a 175 watt Weller iron that came with a pre-tinned tip (a VERY good idea) and I bought a spare at the same time. Ensure the set screw that holds the tip into the iron is tightened every time before you plug the iron in – it makes a BIG difference in heat transfer from the heating element to the tip. I always place solder on the cold tip before plugging it in and as soon as I begin to see smoke (rosin flux is melting) I aggressively feed solder to get the tip very shiny (and often dripping solder onto a scrap board). I keep a SOFT bristle brass or copper wire brush handy to gently scrape the black oxide off the hot iron if it starts to build up between big solder joints. Stay away from using a file in any case – it probably doesn’t do the tip any good, it takes any plating off, and it tends to foul up the file with soft solder as well! You may want to get a smaller “big” iron in the 80- to 100-watt range for heavier soldering – the same general techniques apply.
Hi Jesse,
I have been soldering for over 50 years, and was a certified “A” solderer for the US Gov. before retiring. First off, the blackening is oxidation. Excess heat or heat over a length of time.
I am building an “N” gauge layout, and soldering all connections and rails, other than the isolation blocks. I am designing it for use with DC and DCC selection.
First off, you need to use rosin core solder with non-activated ore mildly activated resin core, and control the tip heat.
I use a Weller MC 5000, with a heater EC1201, with an ETR tip. If you are working on a larger scale, you might want to use a diferent heater, and larger tip. An ETB would be good for S and O gauge.
I use 60/40 non activated, and set the temperature at 800 degrees F. There is no problem with oxidation, and there is enough heat to rapidly heat the joint and flow the solder, without melting the plastic ties, or doing any other damage. Temperature control and the correct flux is the secret. The metal mix, (60/40) is only important as far as the melting point and the strength of the joint. Good luck.
WA2TTD
The further down this thread, the better the advice gets! I, too, am an ol’ geezer that has melted a pound or two of solder in his time. I always look for iron plated tips, because the iron amalgamates with the solder very slowly indeed, thus the tip will give good service for a long time, much longer than copper. The damp sponge is absolutely necessary, most especially when soldering delicate electronic assemblies.
Acid core solder is only for plumbing!
If mechanical strength is needed, use 95/5 tin-silver alloy. In addition to having a higher tensile strength than tin-lead alloy, it is far more resistant to “cold flow,” which is where the solder acts like extremely cold molasses! A slightly corrosive flux is required with this, so wa***he parts well and don’t use it at all for electrical connections.
tebo41, GM, B&FtNRR
Wrong*** acid core should never be used on plumbing if it is copper. The Acid will etch the copper an eventually cause a leak in the joint. Some times this means tearing out dry wall to repair it or worse. I did copper sweating for over 25 years and was taught by professionals that had already learned the hard way from experience.
Sorry to disagree with with one of the contributors (tebot41
There are some here who say to file a solder tip and there are those who say never to do it. The key to whether or not to file is the type of tip you are dealing with. The iron plated tips should never be filed unless they are so old that the plating has gone away, it is pitted badly, and you need to get that last job done before you get a new tip. Straight copper tips however pit very quickly and will need a light dressing of filing (or sanding) often. The more often you file (or sand), the faster the tip disappears. In either case, a damp sponge to clean the tip while in use and keeping the tip tinned will result in the tip lasting as long as it can. I also agree with those who say to get the tip tinned as soon as you can get solder to melt onto it. Letting a “naked” tip heat up to full operating temp will result in oxides that don’t allow easy soldering and may be difficult to remove without damaging the tip. Make sure the parts you are trying to solder are clean and the flux, either in the solder or added externally, is correct for the material and application. Also try not to breathe the fumes coming off the project. They aren’t very healthy for you. An exhaust fan, a breeze blowing the fumes away from you, and/or a respirator are all good ideas.
Any more room for another couple of tips from an electronics tech?
First: 63/37 solder is called “Eutectic” solder because it has no plastic state. That’s when the solder is hotter than its freezing point (or that temp where it becomes solid) but still cooler than its melting point (where it flows like a liquid.) This is also why you have to be careful that you don’t move or nudge something that has been soldered with 60/40 or any other solder. 63/37 is the only solder whose melting point and freezing point are the same temperature, about 835 degrees if I’m not mistaken.[?]
Second, a better method of cleaning off the tip of your iron is to use a brass “sponge.” This is nothing more than a coiled strip of flat brass wire that has been balled up into a sponge shape. Brass sponges clean the excess solder off of the tip better and they don’t cool the tip down like regular wet sponges. They can help remove the corrosion off the tip as well[:)]
Just my[2c]
Joe
I worked as a staff engineer in radio and television stations for several years and soldering was just a daily part of the job. Like so many things we tend to make it more complicated than it is. How can there be this much discussion about something as simple as tinning the tip of a soldering iron? Just go do it!
You may disagree as often as you wish! I don’t expect to quit learning until they’re shoveling dirt in my face. (I always thought the paste flux had a bit of acidic material in it.) I meant that acid core solder has no use known to me around the railroad. With rare exceptions, clean metal will “tin” with rosin core.
tebo41, GM, B&FtN
Hey, fellas, we’re getting a bit testy. The question was asked because the answer was an obstacle to someone. Many thoughtful and informative answers have been provided, and some of them are incongruous. That happens. With so many people with various backgrounds and experience, differences of opinion are inevitable.
One should never belittle the importance that another person ascribes to something. Just because it is old hat to you doesn’t mean it is easily done or comprehended by someone else.
Also, if you must disagree with someone, try not to be disagreeable about it…please.