Zinc pest and/or rot. Isn't there some way to slow it down or stop it?

The short answer......no. Zinc pest occurs from the inside, so no way to stop it.

@woodsyT posted:

I just haven't read anything that suggests any help or cure once this process begins. - just hoping...

That's because there is no cure, it's like death and taxes, it's gonna' happen!

You might slow it down with some sort of resin compound like you use on wood to sort stop dryrot.    It is very liquid and would seep into the cracks.    It might help.

But as said it occurs inside through the whole piece, it just turns to powder, so I don't know how well it would work.

Notably, good alloys never seem to get it.   It is a failure of the metallurgical/chemical makeup of the alloy.   The builders are probably trying to use recycled product and the source material contains contaminants.

I worked in the Steel industry for some years, and  using scrap to make new steel had similar problems.   A  lot of scrap from Junk yards had chromium and other metals that strongly affected the steel metallurgy.    We had to very careful of where and what the scrap was.

well... fudge!

frustrating starts with "F"

@prrjim posted:

You might slow it down with some sort of resin compound like you use on wood to sort stop dryrot.    It is very liquid and would seep into the cracks.    It might help.

But as said it occurs inside through the whole piece, it just turns to powder, so I don't know how well it would work.

Notably, good alloys never seem to get it.   It is a failure of the metallurgical/chemical makeup of the alloy.   The builders are probably trying to use recycled product and the source material contains contaminants.

I worked in the Steel industry for some years, and  using scrap to make new steel had similar problems.   A  lot of scrap from Junk yards had chromium and other metals that strongly affected the steel metallurgy.    We had to very careful of where and what the scrap was.

Yup but your company gave a ***t, these manufacturers could care less. People line up buy them the a few years latter the complaining begins.

Unless the incipient evidence is only cosmetic, by the time most folks find it in frames, trucks, wheels, etc., the part has already departed its original dimensions.  Often that'll result in binding, out-of-gauge, warping that will stress adjacent parts, etc., blah, blah.

There's really no point by then of 'slowing it down', or 'stopping it in its tracks', ...were that even possible.

Dad's Christmas gift from his parents in 1934/5 was a Lionel 366W set...1835E, whistle tender, three two-tone blue 300-series passenger cars.  The tender developed SEVERE zinc rot early on...

Lionel promptly replaced the tender.  Dad kept the warped one...an object of extreme curiosity...and I yet have it along with the original set.  (Notice in the second photo the sheet metal nameplate...split cleanly in half by the FORCES of Zinc Rot as it quickly developed!!!)

Well, we weren't so fortunate on the engine, however.  I was born 10 years later.  Bringing the train set down from the attic and setting it up around the annual scrawny balsam tree at Christmas time was sheer euphoria for me, one of those decorating 'chores' for Dad and everyone else.  I must have been about 5-6 years old by the time he/we discovered that something was not right about the steam chest (cylinder block) on the engine.  It didn't seem right...cockeyed, cracked, even loose when grabbing to handle the (heavy) engine.  Dad took it to a friend's house.   Paul, the tinkerer...and Lionel fan...disassembled the engine enough to identify the extreme zinc rot infecting the steam chest/cylinders) casting.  A few days later we picked up the engine...it looked better...sort of.  Paul had carefully attached (drill/tap) a sheet metal replacement strap over most of the damage that affected the mounting/alignment of the chest.  Anyway, it ran...

...For a few more years.  But, gradually, the zinc rot continued its 'journey' through the casting.  And then we noticed that the flanges on the engine's drivers and trailing wheels were flaking to oblivion, too.  By then we had decided that the train-around-the-tree was passe...and Mom wanted a 'fluffy' pine tree, anyway.  (No more scrawny balsams!)

Fast forward to post-1966.  Moved to Michigan following college graduation.  Dad's 366W (still packed in the Electrolux 'streamliner' vacuum cleaner box) followed me.  Dad said 'It's your problem, now!'  I discovered through the office grapevine Brasseurs in Saginaw, MI.  Took the engine there.  They could get a replacement steam chest and new wheels.  It's still as beautiful and functional as when I picked it up from them.  Of course, unlike the experience with the tender, by the time the engine developed its problems, any 'warranty' period was loooong gone!

Sorry for being long-winded, but Dad's set had both the 'short' and 'long' zinc rot stories to tell.  So, yes...metallurgically-speaking, that munching sound coming from your basement might not be rodents!  It could be the dreaded ZINC RT!!  And it might, indeed, NOT be from your most recently purchased $$$$ possession!

And, no...this sort of event is NOT part of the slogan "Model Railroading is FUN!"  Of course, you're not alone, pal!...FWIW.

KD

You are right about the swelling and warping.   A friend of mine has a series of the Weaver Troop Sleeper cars.   These were highly detailed imports by weaver.    they have plastic shells and diecast frames.     The frames developed the zinc rot and swelled up.   They split and damaged most of the car bodies when they swelled up, a couple severely.  

I have an interesting story too.   I have a bunch of the Atlas USRA hoppers.   These also have plastic superstructures and diecast frames.     About half are paint schemes painted black, and the rest are freight car red.    All of the black ones have developed zinc rot, but none of the ones painted freight car red.

@prrjim posted:

... of the black ones have developed zinc rot, but none of the ones painted freight car red.

See there - this little tidbit - red or black paint seeming to have a difference in outcome. This makes me think there are chemical components in certain paint formulas that exacerbate 'the pest germ' hiding in these castings.  And then I posit (with only two years of chemistry that I nearly flunked and two years of machine shop across 57 years) that there must be some way to slow the decay. 🤞🤞

Instead of working on space travel and battery/solar/electronic/AI technology and all the other "important" stuff can't we pull a couple dozen scientists off that gig to figure out what's going on with the metallurgy in our choo-choos? 👍

@woodsyT posted:

Instead of working on space travel and battery/solar/electronic/AI technology and all the other "important" stuff can't we pull a couple dozen scientists off that gig to figure out what's going on with the metallurgy in our choo-choos? 👍

I think that ship has sailed.

Zinc Rot is a well-known and understood process whereby the zinc used to make die-cast models deteriorates over time due to intercrystalline corrosion caused by lead impurities within it. The impact of Zinc rot is irreversible and is not affected by the manner of model display or storage.

I take your point Woodsy about the difference between the red hopper frames, and the black painted hopper frames.

Only problem here is we don't know if they both came from the same batch (casting) which may have been contaminated.

The red painted frames may have been from the contaminated casting, and the black pained ones may have been from an earlier or later casting.....facts we just don't know, nor will ever know.

It all comes down to "quality control" at the casting stage, and when that occurs off-shore (China), that goes out the window.

I have Buco Swiss made O gauge trains, and the driving wheels of all the loco's are diecast zinc, from the late 1940's up to the mid 1950's, and there is no record of any of these wheels ever suffering "zinc rot". QUALITY CONTROL!!!!

Just my two cents worth.

Peter....Buco Australia.

Where's an alchemist when you need one?

@woodsyT posted:

See there - this little tidbit - red or black paint seeming to have a difference in outcome. This makes me think there are chemical components in certain paint formulas that exacerbate 'the pest germ' hiding in these castings.  And then I posit (with only two years of chemistry that I nearly flunked and two years of machine shop across 57 years) that there must be some way to slow the decay. 🤞🤞

Instead of working on space travel and battery/solar/electronic/AI technology and all the other "important" stuff can't we pull a couple dozen scientists off that gig to figure out what's going on with the metallurgy in our choo-choos? 👍

This has absolutely nothing to do with it. Die cast degradation begins at the ingot. No paint, no humidifier, no dehumidifier can stop it. It boils down to the ingot your models were made from. The vendors would have to refine it on top of refining it, on top of refining it to come up with a pure, contaminant free ingot. Could they do it? Sure, but then the same folks crying about zinc rot would be crying about a 1000 dollar locomotive now being 2000 dollars……if zinc rot bothers you to the point you can’t sleep at night, then go brass,….and leave your worries behind …..☺️

Pat

I encountered my first case of Zinc rot recently. After fiddling with, and breaking a pair of MTH diesel trucks, I bought a new pair, installed them, and have been enjoying the engine since.

I'm with GRJ and Pat on this one....death, taxes, Zinc rot.....not necessarily in that order 🤣🤣

@harmonyards posted:

... to come up with a pure, contaminant free ingot. Could they do it? Sure, but ...

...go brass,….and leave your worries behind...

Pat

  I've read a few zinc-related technical/industry papers on the interwebz and found a couple of threads with info/education on this forum. it has kinda refreshed my thin grasp of metallurgy and you're right on, all of my locos are more than 56 years old and I'm lucky, only a few show light to mild zinc veining/pest. It also seems like the frequency of pest/rot problems is higher in the more recent generations of locos.

and if anybody wants to share some brass with me, you know where to find me - promise I'll take good care of it

Zinc rot on an engine that retails (retailed?) for SEVENTEEN HUNDRED DOLLARS!

Why would anyone buy any more of these high end engines?

What is Lionel’s position on this?

@prrjim posted:

...I have an interesting story too.   I have a bunch of the Atlas USRA hoppers.   These also have plastic superstructures and diecast frames.     About half are paint schemes painted black, and the rest are freight car red.    All of the black ones have developed zinc rot, but none of the ones painted freight car red.

Doesn't it take gold to make red pigment?  Maybe an alchemist or dissimilar metals issue with the minute amount of gold in red paint and zinc rot being held in check.

@CALNNC posted:

Doesn't it take gold to make red pigment?  Maybe an alchemist or dissimilar metals issue with the minute amount of gold in red paint and zinc rot being held in check.

More than likely the black cars just happened to get the bad batch of zinc castings and the red ones didn’t . …..y’all are way overthinking this ……

Pat

"More than likely the black cars just happened to get the bad batch of zinc castings and the red ones didn’t . …..y’all are way overthinking this …"

Apparently, since 1940, folks have been thinking hard on this, from wikipedia:

Since the 1940s, some model railroad hobbyists have claimed,^{[citation needed]} with varying degrees of success, that a method of "pickling" zinc alloy parts by soaking them in vinegar or oxalic acid solution for several minutes before painting and assembling them could prevent or delay the effects of zinc pest.

So, its been 84 years, has anybody found out if this claim has been proven to actually work?

Even "gold" paint does not contain gold, and red paints are produced from non-gold-bearing minerals: see Wiki article on red paints --- https://en.wikipedia.org/wiki/Red_pigments

You have me wondering now I bought two sets of Atlas PRSL passenger cars out of a house with some other items a year or so ago. The trucks fell apart as I was moving them from the packing to the track. I never thought about zinc pest.

@prrjim posted:

.…..  I have a bunch of the Atlas USRA hoppers.   These also have plastic superstructures and diecast frames.     About half are paint schemes painted black, and the rest are freight car red.    All of the black ones have developed zinc rot, but none of the ones painted freight car red.

I think what is being said here, if I’m understanding correctly, is that the hopper cars plastic shells are red and black, not the metal frames.

Both the frames and shells were painted.    The underframe on a hopper car is very visisble.    Actually all the diecast parts, underframe, hopper doors, braces etc on the black cars disintegrated.     I think it is a bad batch of casting and just a coincidence that the black cars are the ones affected - - but Gibbs says there is no such thing as a coincidence.

@CALNNC posted:

... "pickling" zinc alloy parts by soaking them in vinegar or oxalic acid solution for several minutes before painting and assembling them could prevent or delay the effects ..

That's sorta along the lines of my original question.

Years ago while installing custom iron railings the builder/welder had us wash it with oxalic before painting. Something about possible microscopic weld voids corroding/rusting and paint bonding better etcetera to seal it.

Anyhow... After giving this a full 80 or 90 minutes to date 🙄🤓 I haven't found anything in my research/reading. A few papers that discuss problem castings with various zinc blends talks about prepping the casting for coatings -and filling small voids before coating, but I'm finding no hints or suggestions about the rot/pest.

Zinc rot on an engine that retails (retailed?) for SEVENTEEN HUNDRED DOLLARS!

Why would anyone buy any more of these high end engines?

I'm guessing it's because, perchance, there's a bit of 'riverboat gambler' in some of us.  'I want it so bad, I'll take my chances!'

Zinc Rot, post-warrantable catastrophic demise of never-ending migrant variations of electronics, changes in manufacturing sites and sources with geopolitical priorities and no customer sensitivity, mergers and acquisitions changing policies both proactively and post-warrantably, delivered paint colors...or details... having nothing to do with the advertised artistic catalog renderings...or prototypes the "toy" is vaguely representing, etc., etc., blah, blah,.....they're all the unknowns, unknowables, and uncontrollables of the hobby.

So, in terms of the disappointment in finding your investment in pleasure at a 4-figure cost was not so pleasurable after all, it's really not so different from spending that amount, or more, in the purchase into local, state, or national lotteries, is it?  Or that occasional trip to the tribal casino?   Just another craps shoot.

Of course, stupidity comes to mind, also.  It's probably in there somewhere.

@prrjim posted:

- - but Gibbs says there is no such thing as a coincidence.

Sure wish he was back!

Lionel should send you the available replacement parts for free, regardless if you're the original owner or not.

@PRRick posted:

Lionel should send you the available replacement parts for free, regardless if you're the original owner or not.

Don't hold your breath for that to happen.

@PRRick posted:

Lionel should send you the available replacement parts for free, regardless if you're the original owner or not.

What makes you think that the replacement parts are any better than the originals? Probably made at the same time from the same contaminated batch of metal.

This is Ogauge but has anybody experienced zinc rot with Gilbert American Flyer trains?

I believe it is a conspiracy between all the MFG or another way is planned obsolescence!!! The stuff breaks cannot be repaired and we buy new ones to replace the broken ones!!!

So I have a question: When I see restored Dorfan models, how are they put back together?

NO.  Zinc pest has been with us forever as lead is present in all zinc deposits.  It is ironic that $35 train engines, made in the 1940-50s when knowledge and metal testing and technology were poorer, were not as seemed to not be as susceptible, maybe now days because the zinc pest ones have been throw away.

It is now a more serious problem, when engines cost $1000 to up to a few thousands, and buyers rightfully expect to get an excellent, long lasting model train.  The manufactures should solve the zinc pest problem or commit to guaranteeing free replacement parts for at least 10 years or provide a brass or other alloy engine that do not fail, for those prices.

Charlie

romiller49 posted

This is Ogauge but has anybody experienced zinc rot with Gilbert American Flyer trains?

Not exactly, but.... This issue is precisely why you don't see very many AF O gauge steam engines. 99.5% or better were "infected" with zinc pest and have been destroyed.

Chris

LVHR

What’s frustrating about these threads is that people don’t look back to previous discussions about the topic, with the same knowledgeable folks always having to step in to set the record straight.

So repeating myself from earlier threads and expanding on it a bit:

The problem in Chinese toy train production is that the main factory (and let’s be clear, the American company which partners with the factory) outsources production to what have been described as garage-sized operations for such things as diecast frames, couplers and truck frames. (The body shells themselves are produced by the main factory, in almost all cases.) Those small-sized diecast manufacturers too often don’t adhere to best practices, and no one — China, the main factory, the American importer — makes any effort to monitor the production process of these small producers to ensure top quality.

The problem continues because the American companies care only about production costs, which, while understandable, opens the door to problems when standards are ignored. There’s no conspiracy. There’s no planned obsolescence by design for zinc pest. It’s simply an unwillingness of all parties involved to commit to quality control.

The zinc pest problem was very evident in the 1930s and into the 1940s in U.S. production as zinc alloy castings, including for the very costly Lionel 700e Hudson in 1937, became commonplace. It took years for manufacturers to fine tune their zinc casting process, but they did. So the problem is avoidable. But it takes the same commitment that those manufacturers took decades ago. No commitment, no hope.

I understand why manufacturers of toy trains depend on Asian production. The costs for similar work domestically is just too steep for locomotives and other highly detailed models. But appreciation for your customers’ interests should still be the main tenet of your product standards.

@Jim R. posted:

But appreciation for your customers’ interests should still be the main tenet of your product standards.

In your dreams Jim!   The almighty buck is the main tenet of product standards nowadays, and that's not just with model trains!

If everyone would just accept injection molded plastic steam engines then the problem would be solved.  Seriously, in China it is buyer beware and is likely to remain so as far as I can see into the future.

there is an easy solution to Zinc pest or rot. Just keep your trains in their original boxes, along with the other "boxed" trains on your shelves that have yet to be opened. 

@Bill DeBrooke posted:

If everyone would just accept injection molded plastic steam engines then the problem would be solved.  Seriously, in China it is buyer beware and is likely to remain so as far as I can see into the future.

Uh, the zinc pest involves couplers, trucks and frames. There have been very few instances of body castings with zinc pest. So you are offering no solution whatsoever.

Keeping your trains in their unopened boxes won't cure zinc pest, it will keep the problem out of sight and therefore "out of mind!"