MTH RailKing warped metal chassis

Wow!  I wish I could offer a good explanation, but I can only guess that it has something to do with metal fatigue of some sort, perhaps related to stress applied by over-tightening of some mounted component.  I have that exact same set in a wall-mounted display case just a couple of feet from where I'm sitting, but it shows no evidence whatsoever of any frame distortion.

Yes I know what happened in this case. The wrinkled diecast is from zinc pest or another term, zinc rot.  You can look that term up on Google and Wikipedia and you will get more information on this subject. It's an anomaly that's plagued toy manufacturers and even auto parts aswell.

How does one prevent this from happening?  

       
       
You Can't! Sadly this has been going on for a long time. Even the diecast airplane forum and diecast car forum has spoke about this topic too. It's from the factory error in the process of how the materials were cast to start off with. From there time and age are against it. Some slow and some fast on the rotting.

I would offer you a chassis I have from an old Railking F3, but the one I have is made from sheet metal not die-cast.

The die cast model car guys have had a lot of issues with zinc rot or whatever you call it. Cars kept in nice cases in temp control but yet they start to crumble and self destruct. No known cure that I know of.......I'd contact MTH and see if they can offer a fix....even if it means buying a new chassis.....

Most of what I own rests on shelving but I have a few new ones which I keep boxed up because of lack of space.  Every time I open one up to operate I bite my lip from anxiety because I'm fearful that something like this will greet me.  Not a very nice hello.  

I used to collect diecast automobiles and there were pictures of crumbling cars nib in their window boxes suffering from zinc pest.

This is the type of thing that makes one want to keep their collection small.  I used to have over 50 engines. Thru sales I've whittled that down to 5.

Aloha and thanks OGR forum, I never heard of zinc rot and my search of posts using "warp" turned up nothing.  Using "zinc rot" worked and there is at least one mention from Feb 2013 related to passenger trucks.

 

Internet searches found many more references in the diecast model forums.  Still it seems rare enough that my fingers are crossed as I unpack the rest of my O-Gauge collection over the coming weeks.  Don't have much room for a layout but enough for a small loop of track. My plan is to inspect, test, and repack for my retirement in five years.  We are planning a move to the west coast, and a hobby room is on my bucket list.

 

I knew there would be some casualties in my collection, and I still expect to find a leaking battery or two since I didn't think to remove them when I had to quickly pack things up three years ago when a family illness required me to move.

 

I have contacted MTH, after unsuccessfully using their web site to look for parts. Frankly don't expect too much help from them - but I could be wrong.

The issue is contamination of the ZAMAC used in the casting.  The usual culprit is lead contamination either from not so pure original ingots or contamination from reprocessing the flashing/sprue from previous casts.   If the contamination is severe enough the item will warp, blister, spall, etc. etc. over time.  There is nothing you can do to prevent this.  Worst case scenario is the item will literally decompose into dust.

       
       
contact Midge at extension 516 at MTH. Just leave her message with your engine item number and what happened and see if they have the frames still for them. You may have to get a raw casting without paint if it is available. Midge does return phone calls and may leave you a message as to how you will pay for it if the frames are available.

Which is what happened to the K-Line heavyweight passenger car trucks IIRC. I bought a set new at a train show. Got home and found about 50% of the truck side frames crumbling to dust. To thier credit K-Line sent me new parts if I'd do the work myself....which I did. I ended up saving one truck that cracked later when K-Line was gone.....but it had one broken place.

Great info, glad it wasn't something I did.  I did contact Midge at MTH by phone and email, we'll see what happens, and I'll do a follow up post if MTH is helpful.  My backup plan is finding a used set, but hey I have five years!   (And thanks for the offer Bob, it helps to know that some sets use a sheet metal chassis)

 

Alan