Knuckle trouble

[lionelsoni]

I coupled up all 28 of my Railway Express cars yesterday to see whether I could run them on my O27 layout. I was actually pleased to have my first prototypical coupler failure: Instead of just opening under load, the knuckle on a K-Line PRR-REX 7601 "fleet of modernism" car broke in two.

As I have mentioned before, I have experienced quite a bit of "zinc pest" in K-Line castings; and this was surely another example. I got out my stock of broken K-line trucks and found a drawbar that still had its knuckle. I wanted to check it for zinc pest before using it; so I pulled on it with my finger. The coupler body disintegrated! But the knuckle seemed sound; so I transplanted it to the express car.

I think K-Line may go down in history as the new Dorfan.

[msacco]

Bob,
Pretty amazing that the coupler snapped like that. I 've never heard of a modern train company with this problem. Is Zinc pest the same as "pot Metal", where impurities contaminate the zinc casting?

Mike Sacco

[Anonymous]

I have a sizable amount of K-Line and have not had that problem. I have heard of a few people complaining of MTH steamer shell castings having that problem. Could be the recycled metal used to make the castings. Funny thing is I think the Chinese invented and used the casting method way before the Europeans did yet hobbiests sometimes blame the problem on them. Actually it is up to the importers to assure standards.

Dale Hz

[lionelsoni]

Mike, my understanding of "pot metal" is that it is sort of the metallurgical equivalent of stew, that is, whatever will melt in the pot. When that involves zinc and lead, the result is short-lived.

[cnw1995]

What a cool-looking REA train that must've been... I've unprotoypically tied a dark piece of yard between the drawbars for some of my K-line cars - I've experienced the same thing as Bob.

[phillyreading]

Never had that problem with K-Line couplers. Usually they will open early or without any device used to activate them. Had a truck assembly side piece fall apart but K-Line replaced it at no cost to me, this happened on a heavy weight car, had to send K-Line the truck assembly. Generally K-Line did not use a long enough stem piece to keep the coupler closed, so I replaced the stem on one K-Line truck assembly with a Lionel and that fixed the problem.
By the way pot metal is a cheap metal that has no real strength, might be an alloy but not left-over scrag.
Lee Fritz

[jimhaleyscomet]

Does anyone know the production start/end timeframe of K-line zinc pest product?

Jim H

[Anonymous]

Dont think you can pin it down to a time frame or even a company. Lionel and K-Line shared the same factory for production. A bad batch of metal can occur at any time. This is a quality control problem at the factory.

dale hz

[lionelsoni]

On the other hand, I've got a lot of Lionel, much of it much older than my K-Line, and have never seen zinc pest in any Lionel postwar or later. I had a case of it on my Rail King Big Boy, but just on the 10 hatches glued (apparently) to the boiler. I am now awaiting a replacement boiler casting.

[ben10ben]

I know that OGR forum member Scott Smith had a "pimple" appear on both his MTH full-scale unshrouded J and Triplex. They replaced both shells at no cost. I'm sure that he would be glad to give full details of it.

[FJ and G]

Well, K-line is out of business so doubt if any replacement will be forthcoming.

Zinc in old pre-war models was known to be a problem.. How could K-Line (& MTH railking) ever decide to use it in modern-day stuff is beyond me. Here's what I found out about zinc; the bogyman of toy trains:

Zinc is one of the most common elements in the earth's crust. It is found in air, soil, and water, and is present in all foods. Pure zinc is a bluish-white shiny metal.

Zinc has many commercial uses as coatings to prevent rust, in dry cell batteries, and mixed with other metals to make alloys like brass, and bronze. A zinc and copper alloy is used to make pennies in the United States.

zinc is essential to the body but too much can cause cancer. Thus, it would not be wise to eat your zinc-coated trains, unless you eat just a little at a time.

[lionelsoni]

Mmm. Zinc.