Hornby loco metal rot/tin worm...

[Big Jumby 74]

Don't know how many people had bad experiences with the likes of some of the Hornby Brush 2 locos some years ago, when the buffer cowlings started splitting due to the metal beneath having a sort of cancer for want of a better phrase. There was a name for it, maz..something? not sure now.

Just wondering which of their steam outline locos suffered from same problem? Have heard rumours of at least one example of T9 30258 suffering with same to the motor bracket(?). Does anyone know which of their locos (all classes) may have been susceptible to same. Not surprisingly am having problems identifying a list of those that should be avoided...

 

[Peter C]

I don't know if it happens to both metal and plastic, but the "maz..something" you mentioned reminded me of Mazak rot (or zinc pest) - there's an RMWeb thread about it here: https://www.rmweb.co.uk/topic/123769-zinc-pest-mazak-rot-the-affected-models-list/
Though I'm sure someone will be able to come along and say I've got that all wrong! Hopefully that list should be of some use to you, even if it's not specifically related to this metal issue because it's still a list of models to either avoid or be wary about (if such a thing is possible).

-Peter

 

[Big Jumby 74]

Many thanks Peter C. That's exactly what I was after. My interests in East London and depots 30A, 1D etc, had led to me collect a handful of Brush 2's as mentioned, which is when I became aware of the production issues that affected some of those. Never seen any official statement about it, but can only assume it revolved around a certain factory/factories in China for a certain period....who knows?
It's good to have a provisional list of all such products that may be potentially a problem, given that many are now only available via the second hand market. Cheers for your input.

 

[Bertone]

Definitely Hornby T9!
I purchased a new Southern Suburban box set maybe seven years back, then stored for a couple of years + until I built a layout.
The T9 failed almost immediately due to this metal rot on the motor housing casting.
I eventually found a brass replacement housing from eBay (Peter’s Spares) which I slightly modified and superglued in - not perfect but ok if you don’t want to pull too many coaches.

 

[Big Jumby 74]

That's interesting...are you prepared to identify the item by Hornby 'R' number? I know Peters Spares have been a useful 'get out of gaol' card for many modellers over the years, but even they will only have a finite number of spare parts. Thanks for your response btw.

 

[Peter C]

Many thanks Peter C. That's exactly what I was after. My interests in East London and depots 30A, 1D etc, had led to me collect a handful of Brush 2's as mentioned, which is when I became aware of the production issues that affected some of those. Never seen any official statement about it, but can only assume it revolved around a certain factory/factories in China for a certain period....who knows?
It's good to have a provisional list of all such products that may be potentially a problem, given that many are now only available via the second hand market. Cheers for your input.

You're very welcome! I only happened to remember a couple of old YouTube videos I saw on the topic some years ago: there are plenty about if you search for "model railway Mazak Rot" on YouTube. I can't remember quite what the exact problem was - or rather, the cause - but it must have been pretty widespread!

-Peter

 

[Mcr Warrior]

More on the phenomenon in the following Wikipedia article...

Zinc pest - Wikipedia

en.wikipedia.org

Extract...

Zinc pest (from German Zinkpest), also known as zinc rot and zamak rot, is a destructive, intercrystalline corrosion process of zinc alloys containing lead impurities. While impurities of the alloy are the primary cause of the problem, environmental conditions such as high humidity (greater than 65%) may accelerate the process.

 

[Bertone]

That's interesting...are you prepared to identify the item by Hornby 'R' number? I know Peters Spares have been a useful 'get out of gaol' card for many modellers over the years, but even they will only have a finite number of spare parts. Thanks for your response btw.

My T9 that came with the “Southern Suburban 1938“ R2813 set, has the running number of 312.
As it came with the set, I don’t think the loco was allocated a specific separate R number.
Below is the replacement motor mount I used.
Hope that helps.
R

 

[Big Jumby 74]

Thanks Bertone. Will make a note of that, should I go down the T9 route..

 

[4COR]

My dad has exactly the same T9, exactly the same zinc rot, and I've bought the same motor mounting bracket to fix (though haven't got around to having a go yet....).

There is quite a lot of filing to get it to fit from the looks.

 

[Big Jumby 74]

Thanks for that. There's a link up thread in post #2 by Peter C to a list of models so blighted, from the RMweb site. They have asked for people with such locos to add details (of their own faulty loco) to the list. The R2813 boxed set T9 doesn't appear to be on the list as yet.

 

[4COR]

Yep - it should probably be added, but it does look to affect all the T9s about that period (same batch of metal from the looks), so I guess sadly expected