USA Big Boy Zinc Rot!!

[Chuck]

Okay so here's a problem with my USA Trains Big Boy that I'm not very happy about 

 

Before I start complaining thought I'd post that yes I've been in contact with USA Trains about this problem with no response from the Ro's themselves nor service!

 

My Big Boy is showing signs of Zinc rot, Zinc pest, die-cast rot whatever....The easy definition is it's the out-gassing of impurities in the zinc when it was in it's molten state. Here's the shortened Wiki explanation of it...and it can become very serious as in crumble into dust 

 

Quote

Affected objects may show surface irregularities such as small cracks and fractures, blisters or pitting. Over time, the material slowly expands, cracking, buckling and warping in an irreversible process that makes the object exceedingly brittle and prone to fracture, and can eventually shatter the object, destroying it altogether. Due to the expansion process, attached normal material may also be damaged. The occurrence and severity of zinc pest in articles made of susceptible zinc alloys depends both on the concentration of lead impurities in the metal and on the storage conditions of the article in the ensuing decades. Zinc pest is dreaded by collectors of vintage die-cast model trains, toys, or radios, because rare or otherwise valuable items can inescapably be rendered worthless as the process of zinc pest destroys them. Because castings of the same object were usually made from various batches of metal over the production process, some examples of a given toy or model may survive today completely unaffected, while other identical examples may have completely disintegrated. 

 

 

My USA Big Boy problem is the front catwalk/ running board/ walkway on the engineers side is warping down. The brass etched walkway surface is a separately applied piece and has broken loose. It's tough to see but the walkway is definitely warping down.

 

This process started when brand new about 10 years ago and is getting worse.  For the first year this engine was under glass in a display case. One day I noticed black specks alongside the engine...they were paint flakes from the walkway side. I figured just a bad paint spot, touched it up and forgot about it. Now years later it's becoming much worse.

 

Here's some pics showing the warping going on...

 

 

 

 

 

 

 

 

 

The only real "fix" is to replace the whole boiler sub-frame as the walkways are part of it. 

 

As I stated earlier USA Trains has been of no help and this is a manufacturing defect and I even offered to buy a replacement frame....In 2007 I paid $3250.00 for this thing...I don't think I'll be buying anymore USA Die-Cast locos including the FEF unless they make good on this.

 

I'll switch to MTH engines.

 

 

[Chuck]

Here's something else I just noticed...There's a gap forming between the upper boiler and lower sub-frame! That means the whole front boiler sub-frame is warping 

 

What I though to be a sort of rather minor cosmetic issue is much more serious 

 

With just the walkway could have cut it off, made new supports and structure out of brass and bolted it on to boiler sub-frame but if the whole front of the casting is infected with zinc rot then it's junk.

 

 

[benshell]

Yikes, I haven't heard of that before! Wow!

 

I'm glad I haven't noticed any of this on mine. I did notice that it's very cheap pot metal that was difficult to do anything with when I was repairing mine. JB Weld didn't seem to even stick.

 

Do you keep the Big Boy in the house, or somewhere without climate control? I'm reading that can make a difference. Mine spent about a year in the garage when I was working on it, but otherwise stays on display in the house.

 

I guess we better enjoy these locomotives while we have them. This also gives me second thoughts about the FEF-3!

 

 

 

[Chuck]

This locomotive has spent all of it's life indoors with climate control...and I spend lots of $$$ running the ac in the summer just to keep the trains in a low humidity environment. 

 

Zinc rot or pest is fairly common in the o gauge world and has effected just about all the manufacturers such as MTH, Lionel, Atlas, Weaver, Williams etc. over the years.

 

Few years ago there was a video showing workers in China throwing cigarette butts, garbage and spitting into a vessel of molten zinc for making die-cast stuff...figures. 

[ssculptor]

This has been a real problem with old wood  models of shops, often found in museums.  It is the lead that rots and since there is lead in zinc, in some mixtures it gets the zinc also.

What happens is that the castings are OK but as soon as one painted them trouble starts. Over time, with temperature changes, vibration,  and changes in ambient temperatures over time the paint starts to crack. It is hardly noticeable but the cracks let in moisture, The moisture enhances the lead rot and eventually it is only the paint that is present, Th lead alloy is just powder. 

There are museum directors the world around who are tearing their hair out as they see their 6 to 12 foot long sailing ship models fall apart as the cast pulley blocks fall off and the rigging falls onto the floor.  It is no joke. 

There has been a lot of research done over the years and one sure fire solution is to use fittings that are case in brass or copper when making or repairing the models. I do not know ;what can be done for your locomotive. Do you really think that USA Trains will really have new  parts cast in Brass or bronze,or even  aluminum?  Anything but lead or zinc. Yes they should, but I wouldn't hold my breath until they do.

If I owned your rotting locomotive I would fabricate the rotting parts out of brass copper, bronze, steel or aluminum.  It may cost more to have this done than you paid for the model in the first place.

Good luck to us all.

ssculptor

 

[Chuck]

Yes it's very disheartening to see these expensive models destroying themselves! 

 

Well I started working on this Big Boy as going to enhance it a bit and upgrade details etc. I now noticed one walkway support cracked on it's own in the last 2 months so I'll try to stop the rot.

 

Here's a pic of the cracked area. I'll plate it with a brass strip and mount by drilling, threading and bolting. Just may get lucky and stop it as hoping the rot is just in this area. 

 

 

 

 

[enginear joe]

I had one platform end of a modern big USA tank car just disintegrate like that. It must have been cast for it to just fall apart.

[du-bousquetaire]

I have seen examples of zinc rot before, and your running board doesn't look at all like zinc rot. It seems more that it was hit by something that bent the running board frame and broke the stretcher zinc rot takes on a craked surface across the part that resembles an old chunk of cheese that would have been let to dry up (sort of like those in a mosusse trap) with many craks and the zinc just becomes brittle all over, not just at one point like on your big boy. Besides all the zinc rot I have seen has happened on models about at least, I would say 20 to 25 years of age, this would be too early for zinc rot.

[Chuck]

Well just go over to the ogaugerr.com forums and search for zinc pest or rot and you'l see all kinds of threads showing it including newer models built in the 2000's from Lionel, Williams, Alas, MTH etc.

 

The whole running board is warping and the break that I shown is where all the stress is being centered...This is zinc rot in the early stages...that is the metal is still gassing out. Zinc rot doesn't just showup one day where everything crumbles into dust...it's starts out slow and takes years before starts crumbling. I'd say the next few years I will see this running board start crumbling into dust.

 

Odd how I stated in my original post that this running board started warping the first year I had this model while it was under glass! My trains run inside on my big layout and I don't play the Addams Family with them. Dropped??!! I don't even move this beast let alone carry it anywhere and 99% of it's life is spent parked on a siding.   

[Chuck]

Here's a 60 year old Lionel tender showing the effects of zinc rot...notice this piece warped more than crumbled.

 

 

 

Here's a 2005 MTH PRR Boxcab that's showing effects of zinc pest....

 

 

 

[BrianUPheritage]

It's terrible usa trains has not done anything to help you out. I have dealt with there service department before, most recently on a defective hudson I had just bought and they were really good. Mike in parts knows those engines inside out. I am always skeptical of any company that does not stand by a product when this sort of thing happens. I understand not standing by a product if it's abused but that is clearly not the case for you.

[Chuck]

Yeah I agree as I need to call them again and ask Mike what he heard if anything. I'll try to buy a complete frame if I have to but that'll be some big bucks...if they even have one.

[ssculptor]

I wonder if this is related to lead rot.  Remember the old castings we bought for making model ships? A lot were cast in lead or an alloy of lead.  Normally they last a long i but when painted trouble appears. Over time the coating of paint develops cracks, expansion/contraction due to temperature changes, rough handling, witchcraft, who knows?  Nevertheless, the cracks allow moisture to enter the otherwise  airtight covering formed by the paint. Over more time the moisture causes the lead to oxidize (rust) and turn to powder (lead oxide). Eventually the part crumbles.  Ship model museums have a terrible time with this problem as some of the models have hundreds of tiny castings that are disappearing, taking down the rigging on sailing ship models.  

The better solution would be to cast all the parts in a better material, like brass or bronze or copper or stainless steel.   Aluminum is not much better. Ever see an aluminum part that was exposed to the elements over years at a time? 

The solution? The manufacturer of the part must insist on purchasing casting material of a formulation that will not decay over time. Can it be done? or should I ask Whom do you trust? 

Many plastics are not much better. Otherwise I woiuld suggest 3-D printing.  None of the 3-D printing materials have been in existence long enough to determine how they weather time. 

Maybe the solution is for companies to produce these intricate plastic parts using a proven (?) long age material. 

If I have a piece that has crumbled I would just reconstruct it in copper, perhaps. 

Maybe we will see an aftermarket industry appear where guys in their garages (heated) producing replacement parts using the latest 3-D printers and materials. This is an exciting time in terms of manufacturing of items using 3-D printing.  Over time we have gone from the stone age through the bronze age, the metal age (otherwise called the iron age) and maybe now it will be known as the plastic age. 

So how does all this help all of us whose models are disintegrating before our very eyes? 

Good question.

Stephen