After looking at brass engines on the internet I find a lot of used engines with massive amounts of corrosion ,scaling, along with total discoloration of the brass and total destruction of the foam padding in the box. Where were these engines stored? in the bottom holds of banana ships on 6 month voyages? It looks like some actually have holes in the metal, what is the cause of this deterioration? I thought brass was relatively inert (guess not)— new to the game. Keith
Keith.
You lit my curiousity on this one, so I did a little snooping. 1st I went to http://www.corrosion-doctors.org/MatSelect/corrbrass.htm . (Very interesting site).There they list a bunch of reasons about why brass and all other metals corrode. From flawed proportions in the original alloy to environmental faults. Not to mention being held together my solder that can sometimes be VERY acidic) Then I did a Google seach on “foam deterioration” and it hit me like the 6:15 express mail! [:0]
Corrosion of brass occurs many sources, but one in particular jumped out. Acetylene ( A petrochemical). Foam breaks down for other various reasons, and plain old air is one of the listed culprits. (moisture, contaminants, etc.) But foam is made from petrochemicals, and when most compound elements break down, they usually revert to their building blocks. Who’s to say that the foam, as it breaks down, is not releasing petrochemicals like or similar to acetylene onto the model? I’m sure the lubricants and oils on the model already don’t help either. Especially being trapped in a box!
Catch-22 eh?
It may be a total crock, but it does give credence to a friend of mine, who is a brass collector and dealer, who keeps his models in closed glass cases and the boxes with foam in a spare bedroom![:p] Oils, acids and other chemicals from handling seems to affect unpainted brass (even though most have a slight laquer coat) more than painted brass.[:D] His advice, paint em up and run em. They are all going to rot eventually,(like US), so enjoy them. [:D][:D][:D]
If you still participate, and get this message, you might be interested that I used a portion of your ‘research’ on this wheel corrosion subject I’m exploring:
http://www.broadway-limited2.com/forum/viewtopic.php?
f=1&t=1452&sid=8099de4afa54b94f0cc4436a535bf039
http://www.modelrailroadforums.com/forum/showthread.php?t=13212
Being an avid model railroader for many years I seem to recall that some of the foam that was used for awhile was paticularily bad for the models. I do not remember specifics, and the few pieces of brass I have are painted and on the rails. A brass collector would know more details, but it seems to me that there was an article about box foam in either RMC or Model Railroader; in the 80s possibly,(could have been another magazine), and perhaps the Reboxx (spelling) could be a source for more information on this subject.
Paul
Dayton and Mad River RR
This issue of corrosion that you are experiencing seems to be more associated with the alloy proportions being off–a type of QC issue all its own. I suspect that might become more of an issue what with doubling up on mfg outsourcing. I got a couple more brass doodlebugs in containers wherein the foam was kind of breaking apart and there was a bit of corrosion on the wheels–maybe ‘verdigris’?–but not to the extent that yours showed. I just lightly sanded this stuff off----
Corrosion alone is sometimes not as much of a problem as poor soldering or the use of an inferior, cheap solder
Several years ago a woman wanted me to look at a brass locomotive that her father had purchased when he was in Japan with the U.S. military, with the thought that I would buy it from her.
When she opened the box, I could see that several detail parts had fallen off and the solder joints on the boiler were separating. The brass itself was not corroded, but was stuck to the black foam in which the model was packaged. The foam seemed to be turning to mush.
Sorry, no sale.
I wonder if you could treat the entire loco with no-ox and it still take paint if you decide to paint it down the road.
No-OX-Id
Walthers Part # 171-226
A scale, $8.95, currently in stock at Walthers
This product is on-sale today for $7.98
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Bar Mills Scale Model Works |
We have some really old No-Ox-Id in a bottle that we use as a track cleaner. If the formula is the same as what Walthers is selling today, it has an extremely strong, volatile smell indicating to me that it is a petroleum derivative.
It would probably be good for cleaning brass, but I think it would leave a coating thereon that would prevent paint from sticking.
The short answer - The loco is “rusting” because it was made with cheap brass. Sorry, don’t know about the foam.
The long answer - Brass is not brass. There are many different grades of brass and the grades range from totally not rustable to totally rustable. I work in the stainless steel industry and there are many grades of stainless that you can buy. The more expensive, the better the grade. Anything that has to do with food equip. is made from 300 series stainless, 304 or 316 will never rust as most people think of stainless. The 200 and 400 series of stainless will eventually rust, it is just a matter of time. When you shop for stainless always bring a magnet with you, if the steel is magnetic it is cheap. That does not mean that if it is non-magnetic it is not though. I don’t know the specifics of the different brass grades but I am assuming they are the same. The manufacturer obviously decided to cut costs and buy the cheaper grade of brass to manufacture the loco from.
Spearo: Interesting that you mentioned the cheaper metals issue here–this was one of the concerns that I had about what would occur if the bottom line becomes more important to the outsource the further along the business goes. There is a sense among some management types that when the company starts to feel ‘pinched’ in terms of its own margins that they will drop the Quality side of things in order to survive----
Which may create a few more issues down the line----corrosion being one of them
The no-ox that was provided to me had no odor, so it sounds like it may have changes. Also I think you are correct about the no-ox causing paint to not stick.