crumbling, poor rolling trucks???

I have a metal five car intermodal set from Ed R that has Weaver trucks and they roll ten times better!

Sounds like Zinc pest.  Were these stored in a damp location?  Can't really see what you're talking about in the picture.  Take some better photos and send them to Atlas, they might be willing to work with you on replacement trucks.

Joe, if they are all Atlas cars, there is a known problem with shipping damage to trucks and/or diecast body bolsters from the cars bouncing in the hard Styrofoam insert. Though all the damage I've experienced has been busted truck or body bolsters, not sideframes.

sure wish Atlas would slip a foam sheet insert between the truck and body when shipping.

Now I know why the Navy uses "Zincs" for Cathodic Protection, called a sacrificial anode (it deteriorates/corrodes before the metal it's suppose to protect.  Of course we shouldn't be running our trains in seawater , but I wonder if the moisture in the air is to blame?

I think it all came down to some of the Chinese makers not formulating the diecast material properly, too much of this or that and POOF, things start to crumble.

Just another good reason to stay with Athearn trucks with Intermountain wheel sets.....or brass....

It's hard to capture the hairline cracking that's all over these trucks. As I dis-assembled them, they fell totally apart. The side frames were cracked and released the brass bushings. The bolsters crumbled. Some pieces are tiny.

 At first I thought it was from some accident. After looking closer, I realized that the metal has deteriorated. I don't see any signs of moisture on the cars or the packaging.

 I wouldn't think there's many trucks made in America. I wish I could invent trucks with real bearings inside. They work great in G scale. You can pull like ten times as many cars with roller bearings than without, when the cars are weighted properly.

I don't know if you have any recourse with Atlas, but your truck symptoms sadly sound like zinc pest, which is from casting alloy impurities, and has nothing to do with moisture.

With roller bearing trucks, how often do you have a car that won't stay put on the track?  I have some cars now that won't stay where I park them and that's with elcheapo delrin or diecast sideframes.

Joe,

Your description of the problem matches zinc pest exactly. Unfortunately, all you can do is consign the trucks to a junk yard display on your layout (make lemonade...). Meanwhile contact Atlas and see if you have any recourse with them. Worse case scenario is you end up buying new trucks. Your wallet will be thinner, but at least the cars will be moving. BTW, not all Atlas trucks are effected. The problem seems to be batch related. And it is not limited to Atlas. I know just about every manufacturer out there has had this issue at one time or another in the recent past.

Chris

LVHR

Thank you. I did not want to bash Atlas and I have read that this was a known issue. I really just need a direction for replacement trucks. The Weaver trucks that I have, roll great. I can't find many around. I like the look of the new Atlas trucks even better and they seem to roll very well. Before I invest in about 2 dozen + sets of trucks, I would like to know that they will work better than what they'll be replacing. The Atlas metal cars have great detail and are some of my favorite cars. Because they are fairly heavy, I would like to have some really free rolling trucks under them.

 I see they still have the long Atlas flats in recent production and I'm guessing they come with the newer trucks? So I need to ask how well they roll now?? or, haven't any been shipped yet with the newer trucks and couplers???

newest ones here?:

http://www.atlaso.com/o89flatcar6.htm

I have several new Atlas cars that have arrived still in their boxes and more are coming. I'm excited to see how well they roll and act on my RR.

Joe, the plastic Athearn trucks fit pretty well on Atlas cars. I always use IM metal wheelsets with them. and they roll forever!

Zinc anodes deteriorate from electrolysis in a marine environment, not just from being wet, but from stray current in a boat's electrical system and in the water, like in a marina. they are sacrificial to protect other critical items like saildrives or outdrives from corroding.

what Joe has is definitely bad metal

Joe - When Atlas re-entered the O scale market in the 1990's with their line of cars made in China they decided not to use the NMRA spec body bolster height previously used on their 1970's era rolling stock produced by  Roco  (a second perhaps more unfortunate decision was to retain the Roco coupler pocket with snap on lid and unique mounting hole spacing).  As a result if you re-truck an AtlasO car with trucks made with NMRA height bolsters (Athearn, Intermountain, Weaver, Yoder, PSC, and others) you'll need to use a bushing or spacer washers to get the ride height right.  It's easy to do but when viewed at rail height doesn't look as good  as  a similar car set up with body and truck bolsters that match up. 

There was a really good discussionnof this recently on the 3-rail forum.  They know what causes it and how to not let it happen, but some Chinese foundries seem to not care.  You do not see automotive window cranks and convertible top fittings crumble.  You do not see syrup dispensers and salt shaker tops crumble in restaurants.  

Bob Delbridge posted:

Now I know why the Navy uses "Zincs" for Cathodic Protection, called a sacrificial anode (it deteriorates/corrodes before the metal it's suppose to protect.  Of course we shouldn't be running our trains in seawater , but I wonder if the moisture in the air is to blame?

I think it all came down to some of the Chinese makers not formulating the diecast material properly, too much of this or that and POOF, things start to crumble.

Don't want to hijack the thread but;

Bob,

During my years as a machinist with the Army Corps of Engineers,   we did the exact same thing with the lock gates.  Whenever we rehabbed/overhauled a set of lock gates,  we always bolted on numerous anodes(how many depended on the size of the gates) that would be below the waterline for the exact purpose that you described.  The anodes were always bolted on brackets that kept the anodes from touching the metal they were protecting.  It seems to work pretty well as I saw gates that were in service for 30-35 years in the water before overhaul.

The zinc pest was very common with some of the early Williams and early K-line trucks as I have had those turn into dust when I touched them.

Nick

Engineer-Joe posted:

I have some new, old stock cars and some used ones that aren't open. I finally have the room to run them, now that I'm expanding the layout. So I took a bunch out of their boxes and noticed they did not roll well when I put them together. The one Atlas large flat car that's the worse has wheels that won't roll much at all. I noticed the brass sleeve bushings had come out of the side frames. As I was trying to push them back I noticed the side frames looked bent? So I start to unscrew the side frames from their bolsters and everything started to crumble??

 I would have said that maybe the car was dropped in it's past as it was used. The wheels have no wear and the car looks mint? I tore the trucks apart further and noticed their were cracks thru everything? Even the side frames then crumbled apart???

So I've read that this has been a past concern about the cast metal from overseas crumbling in certain runs. Where I'm at now, is considering replacing all the trucks on more than 2 dozen older cars that don't roll well. No other cars seem to have the crumbling, yet most don't roll well at all. I'm including two 5 car sets of Atlas stack wells in that statement.

 I'm tempted to find some type of bearing to insert to help these heavy metal cars roll better. I had a spare set of the newest Atlas trucks with scale width and they seem to roll much better. I don't wish to invest heavily in them only to find out that when 2 or 4 dozen cars are assembled they still roll poorly.

What are U guys using? Are there any better options?

Hey Joe, I ran into this problem a while ago and posted it. Quite of few of my Atlas O "Steam Era Classic" cars had crumbling  bolsters. This is the first I've heard of Atlas RB trucks being affected. This is cause for concern now with all my modern Atlas O rolling stock. Thanks for sharing.

Atlas isn't the only manufacturer of bad metal items. Several years ago I was disassembling an Ertl 50 Chevy COW die cast truck model. It readily fell apart in my hands with very little pressure being applied. So far none other of my die cast collection has had this problem. With some items in the over $130 department, I certainly hope this will not happen to any of those!

I believe the trucks, and casting in general, are made out of an alloy of Zinc that has the trade name of  Zamak: https://en.wikipedia.org/wiki/Zamak

I am not sure what the advantage in casting in, perhaps it takes details better.

The crumbling symptom called Zinc pest is caused by impurities and/or processing, details can be found with a Google search. As I recall, its caused by one of the elements wanting to form a crystalline structure at the expense of the other alloys. Lead (Pb)??

Just like others have said, galvanic corrosion is a different thing. https://en.wikipedia.org/wiki/Galvanic_corrosion

I did a number on something at work, we have to test something in salt water, the original drain valve was plastic on an aluminum tank, when I replaced it with a brass valve, the aluminum pipe corroded. Lesson learned, use a plastic valve, and replace it every three years.

Sounds like manufactures defects and should be replaced by Atlas.

I have had a number of truck bolsters and side frames crumble, and they have all been Atlas. Most of mine are "steam era classics", and Atlas does not have replacement trucks for these since they changed the bolster design, twice I believe. These trucks have another problem and that is some wheel sets have far too much lateral play, and the wheel sets will not follow the truck frame through a switch/turnout, so they pick the points. I measured lateral wheel set play on 15 cars, and they are all over the lot re lateral.

While their cars are nice, their material (and their supplier/builder selection) leaves everything to be desired. Atlas tried to help me by sending a box of replacement trucks, in pairs. If these are installed on a car, the height of the car increases and then the couplers have to be shimmed to make the cars couple with other rolling stock. And the car looks funny. I thought that I might be able to use the wheel sets but, guess what, the axle design (ends) have changed, and the axle length cannot be used elsewhere.

I think it is significant that Atlas has the same deterioration problem with their couplers. I have had four coupler failures and two of them ruined two cabooses (circular layout). So I am buying MTH rolling stock and using MTH two rail trucks, with Kadee couplers, none of which have ever failed.