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Proto 2000 GP-38 Zinc Pest

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Proto 2000 GP-38 Zinc Pest
Posted by DRfan on Sunday, November 18, 2018 10:03 AM

All,  I have seen a recent discussion on another forum that it appears several modelers have noted that their Proto 2000 GP-38 locomotives (HO scale) are suffering warping and crumbling frames which sounds like zinc pest.  You may want to check your locomotives to see if your's is afffected.  Zinc pest is caused by impurities in the metal used by the manufacturer.  It has popped up during the 1950s and recently reappeared with several Marklin locomotives as well.  There is no known way to correct the problem short of replacing the frame.

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Posted by mbinsewi on Sunday, November 18, 2018 10:27 AM

I actually had to look that up, now I know.  I have an old covered hopper track cleaning car that suffers from this.  The inside of the cleaner reservoir is rotting from the inside out.

Mike.

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Posted by SeeYou190 on Sunday, November 18, 2018 10:33 AM

The lead and trailing truck frames, identical pieces, of my Mantua 2-6-6-2 are effected by this problem.

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Wargamers call this "Lead Rot", and it can cause a beautifully paintewd army to fall apart.

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Model Railroaders are lucky that is rarely effects painted/finished pieces. I would rather replace a frame then repain a banner bearer.

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-Kevin

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Posted by gmpullman on Sunday, November 18, 2018 11:00 AM

DRfan
It has popped up during the 1950s and recently reappeared with several Marklin locomotives as well.

I discovered some of the Märklin zinc rot in a set of Trix boxcars I recently purchased:

 Trix1 by Edmund, on Flickr

The underframes of all three cars had warped and deteriorated severely. They expanded to the point of snapping the door rails where the frame fits into the body.

 

https://en.wikipedia.org/wiki/Zinc_pest

 

 

 Trix4 by Edmund, on Flickr

 Trix2 by Edmund, on Flickr

The seller refunded my purchase price and actually, I had planned to replace the underframes to eliminate the swing bracket of the coupler anyway.

My only other encounter with zinc-rot was on the weight of a BLI F7 locomotive. Since it really doesn't have any mechanical function it can stay in place for now.

Thank You, Ed

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Posted by 7j43k on Sunday, November 18, 2018 11:20 AM

I am really surprised that an old-line German company would still be selling models made with contaminated alloy.  

I've got a box of 20 of their Union Pacific 40' boxcars.  I am NOT looking forward to having a look at their frames/floors.  But sooner is better--it's been pointed out that it only gets worse, and that it can damage the plastic bodies.

 

Ed

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Posted by gmpullman on Sunday, November 18, 2018 11:39 AM

7j43k
But sooner is better--it's been pointed out that it only gets worse, and that it can damage the plastic bodies.

I would at least remove the frame from the body, a tight friction fit with a dimple at each side of the truck bolster, so that the frame can continue to expand but not deform the body.

Here's a quick photo-slideshow.

Replacement frames with coupler pockets would be a nice thing to find (Hello, Shapeways?) The underframe didn't have to be zinc, they could have molded it in plastic and used a separate weight.

Good Luck, Ed

 

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Posted by csxns on Sunday, November 18, 2018 1:13 PM

Wonder if the GP60's are affected.

Russell

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Posted by jrbernier on Monday, November 19, 2018 12:52 PM

  I just looked at my collection of P2K GP7/9's from the late 1990/early 2000 era and there is no sign of the problem.  I remember looking at old used stuff from the 50's and there was a lot of zamak 'rot' from that era.  I suspect this is typical of Chinese cost cutting.

  I wonder of the Chinese J2000 stealth jets are going to fall out of the sky over the next few years?

Jim

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Posted by SeeYou190 on Monday, November 19, 2018 2:29 PM

jrbernier
I just looked at my collection of P2K GP7/9's from the late 1990/early 2000 era and there is no sign of the problem.

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I have four Life Like GP 7/9, and one SD-7. All are OK.

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I do not think this is a problem across the entire Proto 2,000 line.

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-Kevin

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Posted by csxns on Monday, November 19, 2018 4:24 PM

jrbernier
r of the Chinese J2000 stealth jets are going to fall out of the sky over the next few years?

They just mightBig Smile.

Russell

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Posted by gmpullman on Monday, November 19, 2018 6:08 PM

SeeYou190
I do not think this is a problem across the entire Proto 2,000 line.

I agree. I would estimate that I have maybe sixty or more Proto 1- and 2000 locomotives, both from the original Life-Like line and later Walthers, in HO and have not had any problems related to zinc pest.

Regards, Ed

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Posted by csxns on Monday, November 19, 2018 6:35 PM

Have four GP38-2's went down to check them out and yes the zinc pest hit them one is so bad that it is stuck in the box got them in 2004 at $109.95 each Crying.

Russell

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Posted by emdmike on Monday, November 19, 2018 8:05 PM

Zinc pest has also hit the O scale crowed with both MTH and Atlas O having issues with body shells on MTH and trucks/couplers on both developing the issue.  And, yes, I attribute it directly to Chinese cost cutting to make a buck. And poor QC on the part of both MTH and Atlas O.  Same for other companies.  I thought at one time, Marklin/Trix had a replacement program for those warped freight car underframes.   Might be worth an email to them in Germany to enquire about replacements(for those unable to build thier own replacements).   Mike the Aspie

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Posted by Mark R. on Monday, November 19, 2018 11:11 PM

I just came across a Proto GP38 recently that the frame was broke in numerous places.

This unfortunate problem also exists in the world of diecast toy cars from the 60s and 70s. I've seen numerous Hot Wheels from the early 70s still sealed in the original blister pack and all broke to pieces.

Mark.

¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ

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Posted by Pruitt on Tuesday, November 20, 2018 8:27 AM

This is really an unacceptable situation.

Corporate sellers (they're not manufacturers anymore - someone else is, and Atlas, BLI, etc. simply specify the product they want manufactured) should be specifying a casting material that will not exhibit this problem at some point. Failing to do so is irresponsible at the least, and they should be held accountable for replacement costs. It isn't as if the rot is a recently discovered characteristic of the material, after all.

If the sellers are specifying materials that are not susceptible tho the problem, they should hold the manufacturer financially responsible, as the manufacturer did not build per the contracted specifications.

Instead, the end purchaser is far too often left holding the bag for the defective items they purchased.

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Posted by riogrande5761 on Tuesday, November 20, 2018 6:03 PM

Pruitt

This is really an unacceptable situation.

Corporate sellers (they're not manufacturers anymore - someone else is,and Atlas, BLI, etc. simply specify the product they want manufactured) should be specifying a casting material that will not exhibit this problem at some point. Failing to do so is irresponsible at the least, and they should be held accountable for replacement costs. It isn't as if the rot is a recently discovered characteristic of the material, after all.

If the sellers are specifying materials that are not susceptible tho the problem, they should hold the manufacturer financially responsible, as the manufacturer did not build per the contracted specifications.

Instead, the end purchaser is far too often left holding the bag for the defective items they purchased.

Some call them importers. 

I agree, should. I imagine everyone agrees but in many cases not much we can do.

Unfortunately many of these items were manufactured 15 or 20 years ago.  Who knew they had an expiration date and would self destruct.

Rio Grande.  The Action Road  - Focus 1977-1983

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Posted by BigDaddy on Tuesday, November 20, 2018 6:11 PM

Three words:

Google Chinese Drywall

Henry

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Posted by Pruitt on Tuesday, November 20, 2018 6:39 PM

riogrande5761
Unfortunately many of these items were manufactured 15 or 20 years ago.  Who knew they had an expiration date and would self destruct.

Pretty much any relatively competent manufacturer working with these materials knew - the problem first cropped up over 50 years ago. I think they just didn't care. Get it out the door cheap and get the money. Spending an extra 5 cents on a material that doesn't eat itself in the relatively short term would reduce profit by that same 5 cents. Can't do that!

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Posted by MARTIN STATION on Tuesday, November 20, 2018 6:39 PM

Hi all,

   I just checked three Protos I have, a GP38-2, GP9, and SW8 I picked up all about the same time in 2004 and they all seem fine. My question is since this seems to mostly effect the P2k GP38-2s I'v read about here, if mine is still ok after all this time, is it going to stay that way? Or is this something that can still happen?

Thanks, Ralph

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Posted by Graham Line on Wednesday, November 21, 2018 12:42 AM

I'm not seeing problems with P2K Geep 7/9/20/30 engines. My Marklin/Trix hoppers and cabooses are marked "Made in China" and the center sill on the hoppers feel like they may be metal. Don't see issues with the two that are close at hand.

 

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Posted by SeeYou190 on Wednesday, November 21, 2018 1:05 AM

MARTIN STATION
Or is this something that can still happen?

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My experience with this problem is 99% with wargaming figures.

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I can tell you that figures made 30 years ago can suddenly develope "lead rot" with no warning. It is like sitting on a time bomb.

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Maybe model trains will give us better luck.

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-Kevin

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Posted by engineman on Friday, May 8, 2020 11:43 AM

I just took apart a Walthers GP20 from the 2013 run and the frame fell apart before I got the shell off.

Gordon S.

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Posted by Overmod on Friday, May 8, 2020 7:48 PM

Thermal cycling is what causes this -- and it may not be excessive heat or excessive cold that marks the phase-change region where the distortion occurs.  

If you have one of these that isn't yet damaged ... take care to keep it in a place that is always temperature controlled.  No storage units, no attics, no train rooms that are only heated when someone's in there.

This isn't 'corrosion', which confuses some people.  

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Posted by BigDaddy on Friday, May 8, 2020 8:11 PM

I've not read that before.  I've seen humidity and impure zinc blamed. 

I have a couple 1980's Mantua steam engines with it.  They lived their whole life in basements, I doubt they ever saw more than 75 degrees and maybe 55 when the power went out after 3 feet of snow, once.

Engineman Welcome to the forum. 

While it is normal that a newbie revives a thread that is years and sometime more than a decade old, it is unheard of that all those that posted are still here and links and pictures work.

We look forward to your future contributions to the forum and there is no charge to start a new thread, although I have to admit, this one fits into the discussion.

 

Henry

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Posted by MisterBeasley on Saturday, May 9, 2020 10:23 AM

Seriously, everyone who has been affected by this problem on a recently manufactured model should contact the manufacturer of importer.  Like it or not, model trains frequently do live in damp basements or hot attics, so manufacturers should take this into account, and only they would know which companies overseas or in the US are actually making models which are susceptible to this.

Let Walthers know.  They don't want to be known as the markets of junk.  Perhaps they can change their practices.

It takes an iron man to play with a toy iron horse. 

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Posted by Lazers on Saturday, May 9, 2020 2:37 PM

Hi, I picked-up a HO P2K GP38-2 here in the UK. It was used, but as new and I was well pleased at £55.00 I was impressed by the amount of detail and add-on detail parts supplied. The only thing I observed was that it noticably weighed less than my Atlas versions.

After reading this post (with some alarm) I am uncertain how to get the Body-shell off the Chassis. I removed the Draw-gear & Screws, the Screws at each end and the two behind one of the Trucks, but Walthers info mentions to not remove the two large Brass Screws? Any advice please, most welcome. Thanks, Paul

"It's the South Shore Line, Jim - but not as we know it".

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Posted by Overmod on Saturday, May 9, 2020 5:07 PM

BigDaddy
I've not read that before.  I've seen humidity and impure zinc blamed. 

That's a different thing, although very real.  Zinc is a highly active metal (it was used in dry-cell batteries, and in very effective zinc-air batteries for things ranging from the very small (hearing aids) to very large (transit buses) and in the 'wrong' sort of alloy plus moisture and oxygen you can get a kind of accelerated corrosion, including self-galvanic effect, with development of zinc oxide (like the basis of the 'white stuff on your nose') which has a higher volume and pushes castings apart from the inside.  The key is the formation of the deposits.

In pure zinc pest, including most of the pictures illustrating the thread, you see no corrosion, only distortion.  You'll also hear people swear up and down that they've kept the components dry and out of dirty air -- and they're right.  What they forget, to their sorrow ... as do people making electrical connections with RoHS-compliant high-tin solder ... is that temperature changes alone can cause remarkable grain growth, swelling, and other effects, without any presence or evidence of corrosion.  (See 'tin whiskers' for an extreme example of some of the phenomena.)

Thermal cycling also affects no few people who buy or own 'historic' pocket watches with enamel dials.  If these are not carefully temperature-controlled the differential expansion of the enamel vs. the brass or other material in the dial substrate can lead to irremediable cracking...

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Posted by SeeYou190 on Sunday, May 10, 2020 8:57 AM

"Zinc Pest Happens"

There is no need to go into theory, or even suggest it can be prevented. If your zinc is bad, it is going to corrode.

As I said earlier, 99% of my experience with zinc corrosion has been in wargaming figures. These are not soldered onto, lubricated, baked in the oven, exposed to chemicals, have electrcity flowing through them, or any other nonsense. They are painted (maybe), then stored indoors, and cherished lovingly.

Every so often, I walk by my display case, and one of my older figures has an arm missing, or loses a knee and falls over. I even have older figures that have "pested-out" while still factory sealer in their blister packs.

It just happens. Suggesting that it can be prevented, or something we do causes it, is not productive. This topic has been discussed into the ground on wargaming forums. 

High quality manufacturers of wargaming figures never had the problem. It is unheard of for a Citadel, Games-Workshop, Reaper, or Ral-Partha figure to have pest. So, it is generally believed the manufacturing process is where the problem begins, so the hobbiest cannot prevent it. It happens.

-Kevin

Living the dream.

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