Proper soldering iron tip care

[KL27x]

Phosphoric acid is da bomb for removing rust from all kinds of tools. Cool they use it for a tip cleaner. It leaves a dark patina, which I dunno what will do for a soldering iron. I suppose in a tinner, maybe it doesn't have a chance to form, and/or if it does it is easily etched away with regular soldering fluxes.

Because of economic reasons however, two component epoxy and a filler from ground marble might be the go to solution for "commercial" restoration.

I am talking about surface polish, not fixing any significant damage. So now half my flooring is a high polished marble. This is an absolutely terrible finish to have, especially in the kitchen. Half the things you will drop or spill will permanently etch and mar this finish, instantly. But try to get in the way of a woman and her dream house.

When I asked, he said they used diamond abrasive... with the giant buffing machine. But it was 3 step process and maybe there was some special sauce for the finish.

[nanofrog]

Not all tip tinners contain ammonium chloride, at least according to their safety data sheets.
The Plato TT-95 has an active ingredient of phosphoric acid diammonium salt.

I hadn't even dug into this.  I was concerned with cost per gram, and ended up with Weller's product as a result.

Phosphoric acid is da bomb for removing rust from all kinds of tools.

Despite having started in Materials Eng., I wasn't aware of this, so good to know (specialized in polymers and electronic materials, so my metals and ceramics knowledge is very basic by comparison). 

FWIW, I've always used acetic acid as vinegar is readily available and inexpensive with decent results. And I could remove more stubborn spots/fine-tune it with wet sanding if necessary (multiple grits if needed). In the case of stainless steel (i.e. INOX), I figured I could always it dip in nitric acid after getting it clean.

... [Phosphoric acid]... leaves a dark patina, which I dunno what will do for a soldering iron. I suppose in a tinner, maybe it doesn't have a chance to form, and/or if it does it is easily etched away with regular soldering fluxes.

As it melts, I suspect it prevents oxygen from coming in contact with the iron plating before the lead-free/tin particles melt and can plate it.

Could be wrong of course, but this is my logic/best educated guess at any rate.

[KL27x]

Nothing wrong with acetic acid, really. Grocery store vinegar is only maybe 5%? It's fast enough. But it stinks. If you have a big job of cleaning/painting steel, the cost/benefit and lack of smell of phosphoric is simply superior.

If you dissolve some zinc or manganese in the phosphoric acid, you can leave a zinc/manganese phosphate plating which is thick enough to add some lasting protection. This is how Parkerizing is done. Just give it oil, after the etch.

Naval jelly is a classical derusting agent. The active ingredient is phosphoric acid.

I used to keep a pint bottle of zinc Parkerizing solution for cleaning tools; I would just reuse it over and over. But I lost it when the plastic bottle eventually cracked. I got a garage in the interim, and rust hasn't been really much of an issue. Vinegar is good nuff in a pinch, but I miss the "good stuff."

A zinc park finish is excellent on a cast iron saw or drill press table. I did this to my bandsaw table when it was outdoors. Covered it in sawdust and wet with solution. Kept it wet for several hours. Years later I did minor touchup to one tiny spot, maybe, which developed just a tiny suggestion of red rust. And it's still gun-metal blue-grey and rust-free, all over.

[Mr. Scram]

And here was me thinking it was new..   I had no idea the subject had been much discussed/abused in the past. LOL., I won't mention it again as you clearly answered the question!

Sod-er-ing is the proper pronunciation, pretty much everywhere in America, AFAIK. Using any other pronunciation would be disrespecting my 3rd grade English teacher.

Most annoying thing to me is people raised in America who fake an accent. I knew a guy who always pronounced V as W and W as V. This is done, like nowhere. In some places, they get mixed up and/or combined a bit, but a 100% reversal is pretty obviously a shit fake accent.

Your American teacher, you mean?

At least no one here is calling it welding, like Chinese tend to do.

[KL27x]

Yes, my American teacher. I understand that the proper pronunciation depends on your location. If a youtuber is AMERICAN, he is probably going to pronounce it sod'-er-ing. And that is not ass-backwards mispronunciation. It is not a cutesy regional thing or southern/hick thing. (Nor is it a northeast/Bahwston thing). It is not a willful mistake, of which we have a LOT. It is not a matter of copying how the teacher sounds. (In grade school, I live in an area with a heavy regional accent, and I do not have it; the pronunciation of soldering has nothing to do with this). My English and Spelling teacher, at least in my school, specifically pointed out in this specific word that the L is completely silent and the O is short. This is part of the curriculum. In a town where I am not even sure anyone owns a soldering iron, and there is no indication Mrs. McGuinness had any particular affinity for electronics or making stained glass windows, the pronunciation of "soldering" is taught to kids who don't even know what soldering is. I believe it is specifically part of the formal curriculum in our grade schools, as one of the prominent exceptions to the rules of phonetical spelling and pronunciation. Outside of that one day in class, I doubt I heard the word in conversation for the next 10 years. But whenever I read it, I could hear it the way I was taught. Yes, I can remember this from 3rd grade. Along with the I before E except after C, shit. Sod'-er-ing is officially the correct pronunciation in America, AFAIK. 

No, my teacher did not try to teach us that "pen" is pronounced as "pin" with a short i. That was the colloquial accent, which was not formally taught, but which came as a bonus.

When an American calls it soul'-der-ing, I assume either 1. he didn't pay attention in class and/or was sick that day. The shit we learn at that age tends to stick. Or 2. His family is from Europe or something. Or 3. he is intentionally trying to sound European. But if he has no accent other than the soul-dering thing, probably 1. This is not something we "pick up" from the cool, colorful teacher in shop class. We are formally taught it well before most of us will have ever seen a soldering iron. It wouldn't matter if our English teacher were British. If he/she were competent, he/she would still be teaching the pronunciation of "solder/soldering" phonetically, as dictated by our curriculum... along with the mandatory "in Britain, we...." story.


So forgive us, if it sounds retarded.

[Mr. Scram]

Yes, my American teacher. I understand that the proper pronunciation depends on your location. If a youtuber is AMERICAN, he is probably going to pronounce it sod-er-ing. And that is not ass-backwards mispronunciation. It is not a cutesy regional thing or southern/hick thing. That is officially the correct pronunciation in America, AFAIK.

It's fine either way. You see the same tiring thing happening with aluminum and aluminium. People need to get over it, we all know what the other means. Regionalism is so 2003.

[albert001]

I have some soldering irons  (Ungar and Weller) with older tips some of which have been sitting around and purchased an 8 oz block of Sal Ammoniac, not for regular use but to cleanup  older tips that appear to have some life after they're cleaned and oxidation removed.

Sal ammoniac is a mineralized form of ammonium chloride.

Ammonium chloride cleans by reacting with surface metal oxides converting it to a metal chloride.

At the same time I'm going to use a lead free steel or copper wire ball  to clean off the tip with abrasion.

I also plan to use a lead free TIP Tinner and Activator Cleaner after cleaning using Sal Ammoniac and wire ball.

[Kasper]

When I worked in production for avionics communications equipment I tested about 10 irons monthly.

When they'd fail, I would tin, wipe on damp sponge, test, and repeat until it passed. Then reprimand the user for not taking care of their iron.

All I have ever done is keep my tips tinned and wipe on damp sponge and I've never had problems with them. 

The other day I damped my sponge with snow because I was too lazy to take my boots off to go in the house and use the sink. It worked but I wouldn't recommend it. Can't wait to get a garage or workshop of some sort.

[nsrmagazin]

A lot of people don't know it. The only way to clean a soldering iron tip is chemically, without any physical interference what so ever.

[KL27x]

A lot of people don't know it. The only way to clean a soldering iron tip is chemically, without any physical interference what so ever.

The iron layer is fairly thick on most quality irons. The oxide layer that disrupts the ability of the tip to tin is very a very thin covering on this iron layer. It is easy to abrade this away with a fine abrasive without damaging the tip. But the chrome layer is very thin and fragile, and it ought be avoided if you use an abrasive. I've sanded and stoned a few Hakko tips and there's a surprising amount of meat in the iron layer. I've never had a Hakko tip die from loss of iron plating.

I've dissected a few and intentionally filed through the plating. It takes a surprising amount of focused filing to get through it, and you will grossly change the shape of the tip by the time you get that deep.

If you are throwing out tips simply because they don't tin anymore, you have nothing to lose by trying a polish or a fine abrasive. A fine stone file under magnification is good because you can get right up to the chrome line. I've never thrown away a tip because it wouldn't wet, and I've never worn thru the iron plating on a tip except thru intentional deconstruction out of curiosity. Cheap firebrands are the exception. They don't have an iron plating, at all. Just a very thin nickel plating.

[nsrmagazin]

The tip  normally has a protective layer(titanium) if you remove that layer by any mechanical action the problems will start.

[Shock]

A lot of people don't know it. The only way to clean a soldering iron tip is chemically, without any physical interference what so ever.

The tip normally has a protective layer (titanium) if you remove that layer by any mechanical action the problems will start.

I think you are confusing drill bits which are TiN (Titanium Nitride) coated with soldering iron tips Tin (Sn 50) coated. Maybe you can explain what chemical process you're using as well?

[nsrmagazin]

I am using only water based flux(please don't tell me its acid based). I don't know exactly the chemical compound of the layer. I was doing this in practical engineering where I learned about soldering iron tips.

[albert001]

OK so a soldering iron tip is made of a copper core plated with iron. Right?

The iron plating is what starts to rust and corrode?

Would it be fees-able to use some sort of rust neutralizer such as vinegar to first neutralize the rust?

There other rust removers/neutralizers products on the market, some of which I have such as naval jelly, rust converter, etc. However I'm uncertain if it would a good idea to attempt to  neutralize the rust?

There's one rust converter sold at ace hardware that uses Tannic acid and an organic polymer.

The first ingredient, tannic acid, reacts with iron oxide (rust) and chemically converts it to iron tannate, a dark-colored stable material. Tannins are a group of water- and alcohol-soluble natural products extracted from fruits, trees and grasses. The second active ingredient, 2-Butoxyethanol, is an organic polymer that provides a protective primer layer. The overall chemical reaction converts rust into a stable, black protective polymeric coating.

Which I don't think would be good for a soldering iron tip, unless protective layer could somehow be removed?

There's another one called Ospho which I believe using also results in a protective layer.

I don't think there's any way to remove protective layers from rust neutralizers  other than grinding or brushing with a copper metal brush.

[KL27x]

The iron plating is what starts to rust and corrode?

If you see holes/craters, it's too late. On a butane iron, for instance, you can burn right through the iron layer. The copper core will slowly but surely dissolve in the solder. On the cheap firebrands, you have only a super thin nickel plating; once that wears through, same thing. If your tip looks pretty much normal, but it just refuses to easily wet in one area, that's where I would clean the tip. This most commonly occurs on my irons when I routinely leave parts of the tip dry, but then for some reason I decide I want that part to wet, again. Chemical or mechanical, it's dealers choice, AFAIC. That "dead spot" will typically still hold solder, but it won't wet, readily. I suspect there are just small spots of oxidation rather than a continuous layer. If the brass wool fails, then just try something stronger.

[tooki]

OK so a soldering iron tip is made of a copper core plated with iron. Right?

[...]

I don't think there's any way to remove protective layers from rust neutralizers  other than grinding or brushing with a copper metal brush.

No. Quality tips are much more complex. Ersa’s, for example, use various layers of iron, nickel, and chrome over the copper core. See p.37 in https://www.kurtzersa.com/fileadmin/medien/members_final/Electronics/9_Medien/9.5_Kataloge/9.5.1_Tools/Ersa_Werkzeugkatalog_eng_web.pdf

[albert001]

Here are a few pics of my tips. As you can see the tips and irons need some cleaning up. The Ungars come with their own heating elements the other are for irons that go to a Weller soldering station.

I'm trying to figure the best approach to clean everything up including the tips, heating elements and parts that secure the tips to the iron.

For cleaning not the actual tip (that heats the solder) would a bench grinder with fine wire brush be to much? Should  be cleaned by hand using a wire brush?

Link to all of the tip pics: https://www.facebook.com/media/set/?set=a.1359197960888418&type=1&l=f5c38e8981

[KL27x]

The steel retaining tube can handle judicious wire brushing, sure. You can polish that back to shiny, no problem. You have to be careful with the tips, though. The part of the solder tips that looks dirty - black and crusty - that's the part of the tip that is not supposed to tin. On most irons, this part is coated with only a very thin chrome plating.* Even a mild abrasive can and will quickly erode this layer. The only part of the tip I advocate abrasives is the very tip where the solder goes.

If brass wool doesn't work, I scrape the black residue with piece of brass.** You have to be careful to scrape in only one direction, towards the pointy end. If you go the other way, you can catch the edge of the chrome plating and it will crack and flake off. Notice, if you damage the chrome, the tip will still work. You won't expose the copper core. You'll just expose the iron layer underneath the chrome. Then your tip will take the solder blob higher up the side, where it is going to be useless. And the tip will now have a larger surface area of solder, so oxidation of the solder will occur faster. This means you will end up having to use a tad more flux and/or wiping and retinning more often than before.

*I have owned (cheap) irons where this part of the tip was coated in some sort of composite or thick paint.

**It's hard to tell in this picture, but any solid, palpably thick black stuff up over the chromed part of the tip is typically from burnt out flux residue. It's not an oxidation of the chrome layer. If the chrome is smooth to begin with, it usually scrapes off, fairly easily. The chrome can also oxidize, though. If you run high temps, it will darken to maybe a bluish grey, and I would just leave that alone. You can't practically shine that back up without also taking off a significant part of that thin chrome plating.

[coppercone2]

if you wanna polish something to a shine you need to use higher then 2000 grit sand paper.

try going to 5000 grit (trizol) and then use a metal polish, which also comes in different grades.

Any diamond/cerium powder comes in mesh size. It does not matter what it is, the action is the same as a milling machine, you remove metal by little particles that have a rake angle.

Diamond is more friable wheras stuff like CBN stays sharper longer but might be less tough for certain things.

The abrasives are specified in micron size.

There is gimmickry related to 'dressing', i.e. the use of worn abrasives to get better surface finish, but its kinda bullshit, because just as with a milling machine you need to properly remove metal. If you have poor cutting edges (rather then smaller particles) you get more heat, which is bad.

What a grinder operator can do is "dress" the wheel down to make it give a 'better' finish but the feedrate and RPM gets all fucked up and you end up heating the work piece alot. The proper way is to use a fully dressed sharp wheel, do the operation as fast as possible with the optimal metal removal rate (and lowest heat generation and highest coolant ingress, you want the coolant spraying right at the cut surface with prejudice), then move to finer wheels.

If you wanna get serious then they have special auxillary diamond wheels which rub against your abrasive (Aluminum or CBN) and sharpen it EVERY time it revolves (called a sharpening wheel), made of diamond, but obviously your wheel wears down faster if you do this. Machine shops don't want to pay for this 'feature'. They rather have a expert that knows all the confusing 'tricks' to get the most out of one wheel rather then pay for multiple spindles or buy multiple grinders etc.


I am not going to get into flatness and tolerances here, (best left to an actual machinist) but this is how grinding actually works. If you look at the 'dust' or 'goo' under a electron microscope you will see it actually makes little slivers that snail up, just like a milling machine or lathe.

I.e. -tricks with worn sand paper are stupid too. Go down to a finer grit instead. Obviously don't skip steps.

With automotive its hard because they build special friable abrasives that crack as you use them, the only reason being to save you steps. It gets very confusing to specify because of this. But its not how sand paper and most grinding wheels are supposed to work. This and the 'goo' or 'dust' appearance of grinding/sanding operations is why people are so fucking confused about it. You are not supposed to deform. Its supposed to cut. Deformations are ugly and they produce lots of heat. Look at electron microscope pictures of a grinding wheel. What the diamond or CBN or alum oxide does is make TONS of little 'end mills' that cut the surface when its properly dressed. A diamond sharpener, stone, etc... gets worn BECAUSE on a microscopic level there is not enough pieces that have a proper cutting geometry. Its not really that clogged etc. You are pounding not cutting at this point. This 'moves' or 'deforms' metal in a elastic manner (like denting) and does not produce a good surface finish or tolerances in most cases

The smoother the surface you have, when you go down to a finer grit the better contact area there is, so the better the shine is (look at a hand scraped surface and see how shiny it gets when you get within 0.0001 flatness, even though you just poke it with carbide on a stick powered with your hands).

How abrasives differ : cutting geometry (i.e. special CBN wheels that have little 'tomb stones' that act as cutters and their lined up some how), friability (they crack to re-sharpen or change in size), absolute hardness (diamond vs aluminum oxide (important when working with ceramics or super alloys or glass), toughness (how long they stay sharp), surface friction (how much heat is generated during the cutting operation, they actually have nitride coated wheels (same reason, to reduce friction AFTER the cut is made on the rake angle), thermal conductivity (how much the wheel absorbs and dissipates along its surface and how much energy is transferred into the coolant). You actually want something like 100PSI water jet 2-3 millimeters above where it cuts spraying HARD, not just dripping on the wheel, to remove heat as much as possible).

All this applies to sand paper, angle grinders, surface grinders, super-finishing and polish.


Most of these factors only effect someone doing large volumes to save money. What you need to know TLDR : use properly dressed/sharpened/fresh abrasive, maintain aggressive removal rate, cool as much as possible, choose a material hard enough for your job (keep in mind diamond is not tough so it will fri quickly and get destroyed on metal but its great for stuff like cement cutting or polishing). Don't try to save money with 'tricks' using worn materials or skip grit sizes unless you know what your doing. Do the rational step down like 120, 150, 200, 300, 400, 600, 800, 1000, 1200, 1500, 2000, 3000, 4000, 5000 grit. Don't go from 12 micron diamonds to 2 micron diamonds.

The more steps the more aggressive and less worn the grinding media will be. When you get experience you might be able to skip some steps (not sure if this is true actually). Problem is you need ALOT of different stuff and most people just don't want to spend that kind of money. I made a sand paper "book" with all the different grits on different pages in little folders (from staples) binder inserts.

Before I saw the electron microscope pictures I had some crazy fucking ideas about what was supposed to happen during grinding.

[KL27x]

Holy tangent, batman!

I think I carry a similar strain to w/e you are infected with. Apologies to OP for the sidetrack.

"There is gimmickry related to 'dressing', i.e. the use of worn abrasives to get better surface finish, but its kinda bullshit, because just as with a milling machine you need to properly remove metal. If you have poor cutting edges (rather then smaller particles) you get more heat, which is bad."

Yes. Aside from heat, there is something else that happens. There is a "skin effect" to solid materials. The bits in the center of a solid object have chemical bonds in 360 degrees, all around. The surface of the material can have different properties. In the case of many metals, there are bits on the surface that can be moved around without losing their bonds. Like moving the loose skin of a cat... but it staying there when you let go. The worn abrasives can sort of act like a finer grit, but they will do more of this, called burnishing, to the surface. The rearrangement of the surface layer of metal can not only polish the surface but it can change the properties, a bit.

You can burnish a steel rod in a lathe by using a hard ball bearing instead of a cutting tool. The right amount of burnishing can leave a better finish and improve corrosion resistance. But too much, and the skin can weaken and be prone to breaking and separating. There are, for instance, aircraft parts that need to be burnished a certain way.

[coppercone2]

thats interesting.

Someone on page 1 started ranting about gun owners/polish discussions.

I think that the burnishing should be considered in your final pass. I need to study it more. It sounds like its just going to improve things when you are done removing metal. If your considering burnishing during your intermediate steps it sounds like it just gets removed anyway.

Search for 'the grinding doctor' on youtube for something like a 80 part video series on grinding.

[coppercone2]

the burnishing thing sounds kinda shady though, because you are mechanically moving the parts so you might introduce a sub-surface void that can do things like hold contamination. And it sounds like you can 'fold' something over, but not have it 'bond' to the same strength as the surrounding material, so if the right force is applied it can be removed and leave a cavity behind, not to mention a particle of unusual size compared to the other particles which were  removed (it reminds me of a cyst for some reason).

Maybe its more useful in moving parts (rather then a surface) because you can trap oil in the voids that gets squished out or something or acts as some kind of damper. Sounds like a problem for high purity work since unless its moved perfectly and re-bonds perfectly you get the start of some kind of well or crack.

But it might make the surface tougher, so you might wanna burnish then carefully remove metal to smooth it out while retaining the hardness? Kind of like grind, thermally harden, regrind carefully? So its almost like light forging?

Does a burnished surface differ from a thermally hardened surface vs a forged surface in any respects other then hardness and depth of changed crystal structure (like corrosion resistance, which I was told is NOT related to anything but the first few atoms layer of the exposed surface in ANY measurable way).

[KL27x]

The way I take it is that burnishing is most usually done to improve corrosion resistance by the mechanism of removing voids, not creating them. The smoothig around of the skin fills in voids and leaves a mirror finish. Yeah, too much burnishing weakens the surface of steel, and it can separate.

It's just a surface effect, so yeah, it's a finishing step.

I like to think that the word "bur" is etymologically related to "burnish." But that's just idle speculation.

The only knowledge I have is armchair internet research and personal observations. I can't answer most of your questions.

[coppercone2]

I don't have room or money for a surface grinder.

But the whole 'learning how to polish something' drove me insane because of all the manufacturers and lack of objective information relating to the physics of whats going on. The grinding doc was the most illuminating so far.

[coppercone2]

Just don't get into semiconductor chemical polish  . There is a youtube series about this. It is complicated.