richhotrain The reason for my last post was that Ed wondered why no copper oxide was found in the crud. Back in 2017 in his post, he speculated that the presence of nickel inhibits formation of copper oxide. I'm no chemist or metallurgist, so I cannot explain the presence of one form of oxide to the exclusion of other forms of oxide (copper or zinc).
The reason for my last post was that Ed wondered why no copper oxide was found in the crud. Back in 2017 in his post, he speculated that the presence of nickel inhibits formation of copper oxide.
I'm no chemist or metallurgist, so I cannot explain the presence of one form of oxide to the exclusion of other forms of oxide (copper or zinc).
Yes, I did.
But I did not say that it was some sort of sacrifical action, where the nickel oxidized as protection for the other two metals.
If only the nickel oxidized, there would be copper and zinc left behind. This would leave you with a layer of brass on the top of your rail.
What I was talking about was BEFORE oxidation happened. Now we're discussing the oxidation.
Ed
Well, as I say, I am no expert, nor chemist, nor metallurgist, but if nickel inhibits formation of copper oxide, wouldn't that explain the absence of copper oxide in the black crud sample provided to the metallurgist for analysis?
Rich
Alton Junction
richhotrain Well, as I say, I am no expert, nor chemist, nor metallurgist, but if nickel inhibits formation of copper oxide, wouldn't that explain the absence of copper oxide in the black crud sample provided to the metallurgist for analysis? Rich
Only if you also found no nickel oxide. Once the nickel is pulled off the surface to become nickel oxide (as found in the experiment) it leaves a layer of exposed copper and zinc. It is no longer there to protect those metals. Therefore they WOULD be reactive.
Lastspikemike richhotrain Well, as I say, I am no expert, nor chemist, nor metallurgist, but if nickel inhibits formation of copper oxide, wouldn't that explain the absence of copper oxide in the black crud sample provided to the metallurgist for analysis? Rich Yes. Nickel silver alloy resists corrosion. The invisible layer of corrosion that forms on the surface inhibits further corrosion as for aluminum and zinc.
Yes.
Nickel silver alloy resists corrosion. The invisible layer of corrosion that forms on the surface inhibits further corrosion as for aluminum and zinc.
You are making an assumption. Not so much that nickel-silver resists corrosion (or oxidation), but on the method and extent of that process. You assume it's the same for the alloy as it is for two other metals.
The visible crud may well contain an oxide of nickel but that doesn't make the crud itself an oxide of nickel. The "corroded" surface of nickel silver is conductive. Therefore, there's something else in the crud that interferes with conductivity.
The visible crud may well contain an oxide of nickel but that doesn't make the crud itself an oxide of nickel.
The "corroded" surface of nickel silver is conductive. Therefore, there's something else in the crud that interferes with conductivity.
Since the "corroded" surface of nickel silver cannot be, by definition, a metal, you are asserting the oxides and sulfides ARE conductive. They are not.
You COULD assert that the corroded surface you are speaking of is mechanical, in that the nickel was removed, leaving a micro-pitted surface of remaining brass. Yes, I can see that as being corroded. And it would be conductive, until the pits and the above surfaces were filled with "crud" (see below). Are you asserting that?
Polishing or "gleaming" nickel silver can have no effect on the corrosion. That begins again immediately you clean off the existing corrosion. Something else is going on. Untouched nickel silver jewellery stays bright and shiny for a long, long time. It slowly darkens over time which is the colour of the oxide very slowly building up.
Polishing or "gleaming" nickel silver can have no effect on the corrosion. That begins again immediately you clean off the existing corrosion. Something else is going on.
Untouched nickel silver jewellery stays bright and shiny for a long, long time. It slowly darkens over time which is the colour of the oxide very slowly building up.
That is also true for brass. It's the "untouched" part.
As an experiment, I polished a large piece of brass, and never touched it again. I placed it in full view on a shelf. It stayed beautifully "gold" for months. Not a chance if'd I'd fondled it with my chemical-exuding hands.
We need to clean off the crud periodically. We cannot stop the oxidation and do not need to. My guess based only on actually cleaning crud is the crud only incidentally contains oxide and that only because we pick that up when we clean off the other stuff, whatever that is. The crud from operating model railroads is plain old fashioned dirt accumulated onto the rails. That's why alcohol and other common solvents clean it off.
We need to clean off the crud periodically. We cannot stop the oxidation and do not need to.
My guess based only on actually cleaning crud is the crud only incidentally contains oxide and that only because we pick that up when we clean off the other stuff, whatever that is.
The crud from operating model railroads is plain old fashioned dirt accumulated onto the rails. That's why alcohol and other common solvents clean it off.
And yet the analysis found 100% nickel oxide ("...the black crud is near 100% pure nickel oxide..."). No room for "crud" in that number.
But, I've cleaned off pretty significant layers of crud from new out of the package ME turnouts so...?????? That "crud" isn't responsive to track cleaning fluids. I grind it off with a track eraser. Peco's is more effective than Atlas' track eraser. Both take off a black residue. The black returns more or less immediately but it's only visible if you wipe the rails. They still look shiny.
But, I've cleaned off pretty significant layers of crud from new out of the package ME turnouts so...??????
That "crud" isn't responsive to track cleaning fluids. I grind it off with a track eraser. Peco's is more effective than Atlas' track eraser. Both take off a black residue. The black returns more or less immediately but it's only visible if you wipe the rails. They still look shiny.
Oxides and sulfides of metals are not going to be removed with organic solvents. IF that's what you've got, and you want it gone, mechanical polishing is probably the best choice. It's up to you how fine a grit you wish to use.
"Crud", it seems to me, should have some sort of organic base to it. Those can be sticky and gooey, which organics can do, but oxides and sulfides, not so much. Those should be removable by an organic solvent. Perhaps one you don't want to use, but don't blame the "crud" for that.
I remind you that "oxidation" and "corrosion" are not interchangeable words.
7j43k richhotrain Well, as I say, I am no expert, nor chemist, nor metallurgist, but if nickel inhibits formation of copper oxide, wouldn't that explain the absence of copper oxide in the black crud sample provided to the metallurgist for analysis? Rich Only if you also found no nickel oxide. Once the nickel is pulled off the surface to become nickel oxide (as found in the experiment) it leaves a layer of exposed copper and zinc. It is no longer there to protect those metals. Therefore they WOULD be reactive. Ed
richhotrain To this day, I still don't know what that black gunk is or what causes the black gunk on the rails and on wheels.
To this day, I still don't know what that black gunk is or what causes the black gunk on the rails and on wheels.
richhotrain richhotrain To this day, I still don't know what that black gunk is or what causes the black gunk on the rails and on wheels. Two days later, I am right back where I started from. I still don't know what that black gunk is or what causes the black gunk on the rails and on wheels. Rich
Two days later, I am right back where I started from. I still don't know what that black gunk is or what causes the black gunk on the rails and on wheels.
I'd like to know, too.
But that's frosting on the cake. We do know we don't like it (the gunk, not the cake). We do know we want to minimize it forming. We do know we want to remove it.
Lastspikemike Oxidation is corrosion. Not all corrosion results from oxidation, of course. But nickel silver rail corrodes in air and so oxidizes.
Oxidation is corrosion. Not all corrosion results from oxidation, of course. But nickel silver rail corrodes in air and so oxidizes.
You've got that backwards. Nickel silver rail oxidizes in air, and so corrodes. Consider that the rail also reacts with sulfur in the air. It does NOT then oxidize, it "sulfides". And corrodes.
Oxides and salts can certainly be conductive. Nickel oxide happens to be one of those.
No. Nickel oxide is not conductive.
It may be that the nickel oxide itself isn't conducting electricity but oxide on nickel does not prevent conductivity.
As I said, nickel oxide is not conductive. If nickel oxide is on the surface of nickel, yes, the nickel "under" the surface remains conductive.
The same holds true for copper wire. The outer surface may be covered with oxides and sulfides, but the interior is still copper, and is still conductive.
Seems kind of obvious, doesn't it?
Table salt conducts electricity.
That might depend on how you define table salt. Sodium chloride is not conductive. If you take the sodium chloride out of table salt, what is left that is conductive?
You might want to read this entertaining link on the subject:
https://van.physics.illinois.edu/qa/listing.php?id=2311
Note the words: "...dry table salt at room temperature is an insulator, with a very high resistivity."
There seem to be two varieties of crud on rails: harder oxides and softer whatever. It's the whatever that responds to cleaning fluids.
Yeah, that's likely true. And so one's track gets cleaned. Hooray.
Nickel silver oxide is conductive.
Do we really care if the black crud is conductive or not?
My problem with the black crud is not conductivity. My problem with the black crud is derailments.
Whether the black crud is conductive or not, I have never experienced a problem with power loss because the spots of black crud along the rails are too small to make a difference. However, when black crud builds up on wheels, particularly on rolling stock, I begin to experience derailments because the wheel surfaces can no longer hold the rails.
selector Nickel silver oxide is conductive.
"Nickel silver oxide" does not exist.
Oxides of the metals in nickel-silver DO exist. They are nickel oxide, zinc oxide, and copper oxide.
None of those oxides are conductive.
richhotrain Do we really care if the black crud is conductive or not? My problem with the black crud is not conductivity. My problem with the black crud is derailments. Whether the black crud is conductive or not, I have never experienced a problem with power loss because the spots of black crud along the rails are too small to make a difference. However, when black crud builds up on wheels, particularly on rolling stock, I begin to experience derailments because the wheel surfaces can no longer hold the rails. Rich
My suggestion is to clean your wheels before the buildup gets that thick.
No fun, of course (anyone out there LIKE cleaning wheels?).
If you want to minimize your problem, you need to:
Have your layout in as clean an environment as possible. Make it dust free. A real ceiling overhead. A non-carpeted floor. Minimize air flow from other dusty areas. Vacuum the floor frequently. You don't want dust. A swell benefit is the dust won't cover your layout, if it doesn't exist--it's not just the rails.
Minimize lubricants on rails. That is almost surely the source of the binding goo that joins all the particles together to make crud. Don't allow rolling stock and locomotves to leak lubes onto the rails.
Since there'll still be crud (hopefully at a much lower level) anyway, a liquid track cleaner should be used "as necessary". I like alcohol because it's comparatively non-reactive and evaporates completely. I hear good things about the CMX cleaner.
If you do all this and you still have wheel crud, you're just going to have to suck it up and clean the wheels. But cutting back the frequency of doing that should feel pleasant.
7j43k selector Nickel silver oxide is conductive. "Nickel silver oxide" does not exist
"Nickel silver oxide" does not exist
"[Nickel silver] is preferred for the track in electrically powered model railway layouts, as its oxide is conductive."
Seriously, of course, the idea of a protective oxide layer thin enough to allow electrical conduction is well-established. Chromium and aluminum are hellishly reactive toward oxygen, but they promptly acquire reasonably tough oxide skins -- that not incidentally are both self-limiting and inherently self-healing -- that protect them nicely. That this effect operates in cupronickel rail to avoid 'copper oxide' tarnish is clear, as is that it is present in the zinc/cobalt/arsenic bearing versions of German silver or paktong "nickel silvers".
The classical issues with cupronickel corrosion involve sulfiding and ammonia (as found in cat pee). In the bad old acid-rain days before the EPA in the Northeast, when high-sulfur coal was a common fuel and it was rare to be able to see below 72nd St. from the George Washington Bridge before things disappeared in the "fog", it was impossible to keep silver from turning black in what seemed a matter of weeks. That was fixed, and then sulfur was removed from liquid fuels, most notably since the introduction of ULSD.
Incidentally copper oxide is actually a semiconductor, with an interesting history...
(Just for consistency, if you have an interest in conductive oxides but don't know how they could 'work' -- start here... and follow up with references cited there.)
Lastspikemike selector Nickel silver oxide is conductive. Yes it is. Nickel Silver forms an oxide on its surface which protects it from rapid oxidation. The nickel silver continues to conduct electricity despite this oxide on its surface. Chemically, the oxide itself is a nickel oxide but it seems it remains somehow combined with the alloy at the surface which permits conductivity. It is not possible to determine for sure how the conductivity works. Chromium in iron seems to create stainless steel in a similar way. The presence of chromium at the surface of the iron inhibits the formation of iron oxide.
Yes it is. Nickel Silver forms an oxide on its surface which protects it from rapid oxidation. The nickel silver continues to conduct electricity despite this oxide on its surface.
Chemically, the oxide itself is a nickel oxide but it seems it remains somehow combined with the alloy at the surface which permits conductivity. It is not possible to determine for sure how the conductivity works.
Chromium in iron seems to create stainless steel in a similar way. The presence of chromium at the surface of the iron inhibits the formation of iron oxide.
NO, it is not. You are again describing an oxide coating on a metal, and then claiming that because the metal is conductive, so is the oxide on it's surface.
The "inhibition" of oxide formation is not the same thing as the oxide itself. On the one hand, we have the rate of formation of oxides. On the other, we have the oxides themselves. The claim "Nickel silver oxide is conductive" is about the latter, not the former.
An alloy is essentialy a new metal, this process can sometimes be reversed but many times the only way to get a base metal is to eliminate another componant of the alloy. This is because in an alloy the electrons have merged. We are getting into sub-atomic particles here.
Then, Overmod, your assignment is to tell us the conductivity of nickel-silver oxide. Or the oxides of the alloy metals.
And compare/contrast them with the same numbers for the metals/alloys themselves.
rrebell An alloy is essentialy a new metal, this process can sometimes be reversed but many times the only way to get a base metal is to eliminate another componant of the alloy. This is because in an alloy the electrons have merged. We are getting into sub-atomic particles here.
Merged?
rrebellAn alloy is essentially a new metal, this process can sometimes be reversed but many times the only way to get a base metal is to eliminate another component of the alloy.
Naturally if you want to get 'pure' elemental metal out of an alloy, you need to perform separation (usually chemical). Very great sophistication in doing this has been achieved over the years, notably in smelting and 'nuclear power'.
This is because in an alloy the electrons have merged.
Now to take up the issue of superconductivity is another matter entirely... but that's not metallic conduction, and works with different branches of physics.
We are getting into sub-atomic particles here.
Don't always use the correct terminoligy, not even in model railroading but I think you get my thoughts and to someone not in the field, sub atomic is anything under the size of an atom and thereby the parts of an atom are smaller. Of course termanoligy changes with time, first by people in the field of knowledge. As a side note, WE NEED SPELL CHECK BACK !!!!!
It is often a delight to see things that were formerly mysterious come to be explained by better science. When I was young, the phenomenon of 'creep' in metals was still as much black magic as the action of many common alloy constituents known empirically to be highly effective in fractions of a percent. Now we know, or at least can predictively specify, much more about what works. The T1 Trust project was able to reconstruct the alloys involved in High Dynamic rod steels in less than a year, and to project improvements in practical locomotive rod metallurgy (e.g. cerium) in little more time.
Electrons are a special case because they don't behave like the rest of the 'subatomic particles' and in fact I think they have a different origin and composition. Of course I also thought the 'ace' theory more attractive than Gell-Mann's quark theory, so don't take that as a given. But there is nothing mysterious about their action in electricity, and really hasn't been since Faraday figured it out by the 1830s...
7j43k richhotrain Do we really care if the black crud is conductive or not? My problem with the black crud is not conductivity. My problem with the black crud is derailments. Whether the black crud is conductive or not, I have never experienced a problem with power loss because the spots of black crud along the rails are too small to make a difference. However, when black crud builds up on wheels, particularly on rolling stock, I begin to experience derailments because the wheel surfaces can no longer hold the rails. Rich My suggestion is to clean your wheels before the buildup gets that thick.
richhotrain With over 100 pieces of rolling stock on my layout, that would be quite a task to pick up each and every car to examine the wheels, and how often would I have to do that. It is easier to just wait for a piece of rolling stock to misbehave and then clean the offender. Rich
With over 100 pieces of rolling stock on my layout, that would be quite a task to pick up each and every car to examine the wheels, and how often would I have to do that. It is easier to just wait for a piece of rolling stock to misbehave and then clean the offender.
Not actually an unreasonable approach, when you put it that way.
Ya know, that can simulate pretty effectively a run-down poorly run railroad. Derailments would be a fact-of-life. An option for SOME people (say those who are more into operation than train watching) would be to try to recreate the derailment recovery. You might simply have to tote a rerailing frog over. Or you might have to bring in something more, uh, intimidating.
7j43k richhotrain With over 100 pieces of rolling stock on my layout, that would be quite a task to pick up each and every car to examine the wheels, and how often would I have to do that. It is easier to just wait for a piece of rolling stock to misbehave and then clean the offender. Rich Not actually an unreasonable approach, when you put it that way. Ya know, that can simulate pretty effectively a run-down poorly run railroad. Derailments would be a fact-of-life. An option for SOME people (say those who are more into operation than train watching) would be to try to recreate the derailment recovery. You might simply have to tote a rerailing frog over. Or you might have to bring in something more, uh, intimidating. Ed
Lastspikemike 7j43k Merged? Ed Yup.
7j43k Merged? Ed
Yup.
merge: combine or cause to combine to form a single entity.
So you think that all the electrons merge to form a single entity, kind of a giant humongous electron big enough to have a name, like Mike. Yes, Mike the (giant) electron. (And you also think that table salt is conductive.)
I will disagree. I say the electrons do NOT merge into a single entity. I say they all stay their happy little individual negative selves. At least on the scale we're talking about (electricity, conductivity, and insulators)
Ever wonder why metals conduct electricity while other materials do not?
Not after it was explained in my chemistry class.
Think about the conductivity of air. All will become much clearer.
Think about the conductivity of air.
All will become much clearer.
OK. I'm thinkin'. I'm thinking that if air was conductive, we'd all have some pretty nasty shorts between our two rails.
Then you can consider the conductivity of semi conductors.
Did that too, in my electrical engineering and my materials science classes.
And super cooled materials.
Didn't spend much time on that in school. Perhaps you did. That was a more specialized course of study I didn't take.
And salt water.
Again: that chemistry class.
And my favourite: Plasma......
Your favorite, eh? I bet there's an interesting story behind THAT!
Common experience shows that nickel silver alloy conducts electricity despite being coated almost immediately with oxides.
I did just say that a post or two ago.
Technically, pure nickel oxide does conduct electricity just not so much at model railroading temperatures. Even those achieved in Athearn motors.
richhotrainIt is easier to just wait for a piece of rolling stock to misbehave and then clean the offender.
If you're dealing with a buildup of gunk on the wheel tread that actually causes derailments I have to believe your "rail/wheel hygene" needs to be stepped up a notch, Rich.
One of the downsides to continually runing cars with that much gunk is that the offal gets re-deposited onto what is thought to be "clean" rail.
I, too, probably have in the neighborhood of 200 freight and passenger cars on the layout, possibly that many more in staging or off-layout storage. Sometimes I'll pick up a random sampling of cars that have been recently active for an evaluation of wheel condition. Most times the wheels are clean and shiny.
Oddly enough I sometimes come across a few cars that are beginning to show the buildup of the gunk. All my cars have metal wheels. Probably 75% of them are Kadee. Many of the others are plated brass. Some wheels seem to like to collect gunk while others seem to never need cleaning.
I was suprised recently when I started gathering some of the fourteen cars of a PRR Congressional Limited consist that I have been running quite a bit lately.
These are brass cars and have one wheel insulated and they had been installed incorrectly from the factory. Instead of the leading pair picking up from rail A and the trailing pair from rail B the trucks were installed with all four insulated wheels on one side and the "hot" wheels on the other.
The reason I mention this is that after maybe ten hours of total running time I discovered that the right-front pair of wheels (when the car is flipped over, so actually the left side of the car) and the left-rear pair were accumulating the gunk while the opposite wheels were staying factory-plated finish clean.
All fourteen cars. Why? There are forces at play here that could confound mere mortals! What effect does the constant voltage on the rail have with the deposition of the gunk? Other forums have looked into the various cleaning fluids and resulting composition of the micro-arcing spent oxide detritus. The proponents there have suggested that cleaning fluids be "non-polar" in order to battle this "micro-arcing".
I switched from using 99% isopropyl to mineral spirits in my track cleaning fluid. Maybe it is too soon to evaluate but I really haven't noticed too much of a difference in the results. I generally don't have much of a problem with keeping rails sufficiently clean.
I believe one big contributor for me is the fact that I have painted the sides of the rail and I paint the faces of the car wheels and sometimes the backs. I'm sure there's a percentage of this paint residue that gets rubbed off and is picked up on the wheel treads eventually.
I just wonder how much of your black crud has been picked up by wheel treads only to be redeposited on the rail head repeatedly? Maybe you should spend a little more time to systematically cycle your rolling stock into a wheel cleaning routine.
I keep a length of flex track handy and lay a piece of heavy paper towel over it, lightly soaked with mineral spirits and give the car a few passes until the dirt trails have disappeared. I usually grab a random sampling of five or six cars at a time to get this treatment every few days.
Regards, Ed
gmpullman richhotrain It is easier to just wait for a piece of rolling stock to misbehave and then clean the offender. If you're dealing with a buildup of gunk on the wheel tread that actually causes derailments I have to believe your "rail/wheel hygene" needs to be stepped up a notch, Rich.
richhotrain It is easier to just wait for a piece of rolling stock to misbehave and then clean the offender.
But, I'll tell you what. I will meet you halfway, so to speak. I will remove the other 11 covered hoppers and inspect the wheels for crud.
Lastspikemike To an engineer the world looks different than it does to most of us.
To an engineer the world looks different than it does to most of us.
And to an astronaut, even more different.
Electrons aren't particles. Or are they?
electron: a stable subatomic particle......
Metals share their electrons throughout the alloy.
Are you sure? Note that only 7% of nickel's electrons are in the outer shell, and those are the ones involved with electricity. Maybe the remaining ones stay snug at home.
So, is the nickel in nickel silver still nickel electrically speaking?
Is the mass of shared electrons just a cloud of electrons?
Does it matter?
Are they even really there?
If they're not, our trains don't go.
If so, where are they exactly (that's sufficiently a trick question as to be rhetorical).
Heisenberg can tell you that. Exactly. Ba-da-bum!
Salt conducts electricity if it's mixed with water, you'll recall that water is an insulator. Until it isn't at around 100volts.
Yes it does. But you, sadly, did not say that. What YOU said was, uh, wrong.
Ben Franklin confirmed that air conducts electricity. Or was that air just plasma by then?
I'll go with plasma for $80!
And so on. I can out pedant the most determined pedant you know. I have the stamina.
And so on.
I can out pedant the most determined pedant you know. I have the stamina.
You certainly have the stamina. But you don't really know much about what you're talking about. So I'm not sure you can really call yourself a pedant.
Point of this thread was supposed to be about cleaning crud off the rails and now we're just off the rails.
Not really. Some of us have been having a parallel conversation about the real subject. This was just a bit of fun.
gmpullman One of the downsides to continually runing cars with that much gunk is that the offal gets re-deposited onto what is thought to be "clean" rail.
Whether it begins on the wheels or gets picked up by the wheels, does it get deposited, or redeposited, on the rails? In other words, can black crud on wheels get transferred to the rails?
Which wheels are more susceptible to black crud? Locomotive wheels or rolling stock wheels?
I'd look into the potential resemblance of that finely-divided nickel deposit to Rieke nickel, and its ability to affect oil or other ambient organic contamination on the layout, as potential origins for the gunk and its binding. That might be overkill, of course, but it might account for 'black' plastic-like crap of otherwise 'mystical' origin.
Actual results from people who experience the 'black crap' are needed. Why this should apparently easily transfer to wheels and then be hard to remove requires some analytical thinking.
Living the dream.