I wonder that too. What effect does climate have to retard the progression of zinc rot? I haven't had the guts to check my fleet, but there's very little humidity here in my basement.
This is a long shot but has anyone tried an ultrasonic cleaner. I'm not saying it IS the solution at all , , , but it is a maybe ....... I'm guessing it might work by having all the small loose particles break out through vibration. I've seen it done with alloy pistons stuck in cylinder bores. At the same time it could strip the paint right off ....... yikes !
In regard to the frames that have failed .......... Are they stored in conditions that are humid and them at some time the temperature can drop below freezing ? If the frames can admit moisture through microscopic holes (pourus castings) and it freezes that tiny bit of ice can bust things easily. I just checked mine and they are fine.
I have had an ultrasonic cleaner for about 20 years. I works great. I cleaned a lot of my old N gauge stuff before selling it. Not on e-Bay.
All of my equipment is and always has been stored in a climate controlled environment. Have two other units I need to check this weekend that I should have checked before reaching out to Intermountain. As of today, nothing back from them on the issue.
It's been a while since I read up on zinc rot but, IIRC, it's not a simple corrosion issue like rust. It's more of a reaction between elements within the alloy(?) itself as I believe someone stated above. IIRC, while the train room and/or storage environment can perhaps slow or hasten the process, if it's going to happen it's going to happen.
Well, the good thing is, IM has another run of SD40T-2s planned. I reserved mine March 2015. Any day now.....
For a while I thought it was due to the current passing through the frame halves. But then I had it happen to a locomotive that had not even been run yet. Humidity or thermal issues are not the cause because they have always been stored in the house in a temperature controlled environment. So I have no idea why it is happening because it is not temperature or humidity related. It is not electricity related, and I think we can agree the the phase of the moon is not the case either. It boils down to a chemical imbalance in the mix. Corrosion is related to oxidation and that is cause by a chemical imbalance. So that leads us back to either a chemical imbalance it the alloy, or possibly by a cleaning agent applied incorrectly when the frame half was released from the mold. It is a sad thing because I really like the Tunnel Motor locomotives. They eased my DRGW angst when they were announced.
Oh , aaaaaaand , for those trying to rescue a body shell part of it does appear to come off without need to pry. It is securely clipped on but with a bit of careful wriggling the dynamic brake fan section came off without damage. You probably already knew this .... Be careful of the handrails.
Funny you should say cleaning agent. My dad had new glasses and the metal frame broke after about 4 months. We put it down to faulty manufacture. About a year later I needed new glasses and went to the same optometrist and he had found out what caused the mystery break. It turned out to be dish washing liquid triggered an acid attack. They don't stock those frames any more. So it could be something quite innocent looking that started the whole problem long long ago.
Atlas still has the SD50/60 frame halves on their website. I seem to recall reading something in the past that suggests you can modify them to fit the IM components.
It's lead (pb) interacting with zinc. If there is more than .25% lead in the mixture then zinc pest will occur. That lesson was learned domestically in the mid 20th century and since is refined to 99.99% lead free. It's believed that these more recent issues are due to scrap metal with too much lead being used in the smelters.
I am a Theoretical Physicist, Mathematician and Electrical Engineer by trade, so I do not delve too deeply into metallurgy. As I concluded it has to be the mixture of the alloy and that is far as my skills can take me. If you want to discuss Unified Field Theory or String Theory or the harmonics of the DCC signals on wire cabling, well we can go into Extinction functions of Harmonics and all that stuff, but I am will to bet there would not be very many who want that. Suffices to say a crappy mixture makes a crappy frame. Which was my point in my last message.
I used to have a large accumulation of Kato, Atlas, IMR, Micro-trains and a few odds and ends. Then the forced downsizing came. I now only own items made by Kato and freight cars (only) made by Micro-trains. Life is easier this way.
I don't own any IM but mainly because their offerings don't fit in with what I model. As far as Atlas goes I haven't had any problems I couldn't easily resolve and the same with Kato. The interesting thing is the DCC ready Life Like RS-2's, GP18's, and GP20's have been just as trouble free as the others.
