Atlas Code 55 Flex Corrosion: Lets Talk About That

[Maletrain]

When I get over the damn Flu, I'll do some testing with that same glue and some copper and brass.

But, the point is that Ed's rail has corroded, and all it has been exposed to (that he knows about) is white glue.  But, there are really many types of white glue from many vendors.  So, it might be a glue lot issue instead of a rail lot issue.

Regarding ship building with copper alloys:  Pure copper, and better, bronze were the ancient choices, not brass.  Bronze is copper and tin, while brass is copper and zinc (but both have formulations that include other metals for various property effects).  Modern copper-nickel alloys designed for seawater exposure are more like Monel, which is a group of alloys of nickel (from 52 to 68%) and copper, with small amounts of iron, manganese, carbon, and silicon. Monel is not considered to be a "cupronickel" alloy because it has less than 60% copper.

The usual formulation of "nickel silver" is 60% copper, 20% nickel and 20% zinc.  So, the zinc may  be the issue.  Or maybe some contaminant in the alloy that was on the floor in China when the swept up the shavings to add to the next batch.

[Maletrain]

OK, I did some experiments and here's what I found:

I used a plain steel nail, a piece of machined brass, and a piece of copper plate for testing.  I do not have a bit of Atlas code 55 rail to test.

I tried several glues, including Aleene's Tacky, Tight Bond All Purpose, Elmer's Glue All and Elmer's School Glue.  None of these made any of the test pieces corrode.

So, I went looking for the old bottle of glue I had used that had corroded the nails.  I am pretty sure it was Elmer's Glue All.  I found what I think I used before, and, at this point, it is mostly congealed in its container.  But, I am pretty sure that I remember that when I had used it before, it was partially separated into a thin clear fluid layer on top of the opaque white stuff, and I mixed it before using it.

I took some not-so-congealed parts of that to put on the test pieces, and noted that there was some rust on the nail when the glue dried to clear, but no indication of effect on the brass or copper.  But, as before, I then put some water on all 3 samples to rewet them, and let them dry for a day.  That did produce some green corrosion on the brass sample, but not the copper. 

So, my best guess is that using really old white glue, at least the Elmer's brand, can result in a corrosive effect on copper/zinc alloy.  Not sure that extends to copper-NICKEL-zinc "nickel silver" alloys, but it seems likely.

So, Ed, do you know what sort of glue you might have used on those rails that your picture shows were corroded? You did say that "This was track hit with a little white glue and water to hold it down, but nothing else."

[Ed Kapuscinski]

I'm almost certain it was some regular elmer's white glue.

The thing that I'm finding perplexing is the spotty nature of it. It's not everywhere and it's not consistent.

I'm almost certain it's being caused by oxidation of the copper in the alloy.

I just wish I could find a way to tell ahead of installation which pieces of track will do it and what won't.

[Mark5]

So very weird. Diluted Elmer's glue was the "standard" ballast securing method going back at least to the sixties (1960s).

Personally, I never had a problem using it (though it has been some years  ).

Has the Elmer's "recipe" changed over the years?

[Lemosteam]

Ed, what kind of water do you have, it it refined city water or hard country water.

Sorry in advance if this has already been mentioned.

Copper pipe will oxidize over time when certain chemicals in the water are in constant contact with the copper.  Maybe its not the glue at all but the water you are using to dilute it with.

[dem34]

is the grout you ballast your track with retaining moisture?

[Scottl]

Grouts are typically a mixture of sand or filler, cement (carbonates), polymers for binding and sealing, and colorant.  In principle, simple cement grouts can absorb water, but modern ones are designed to be water repellant to minimize the risk of staining and cracking.  The chemistry of most cements is not particularly of risk to metals as they are alkaline.

I personally doubt the grout or glue are the problem here.  I think the most likely problem is that there is a manufacturing defect, in the sense that there are some impurities in the composition of the rail alloy.  This could explain a localized problem on a given piece of rail or with particular batches, and the occurrence of rail oxidation in other situations besides what @Ed Kapuscinski is reporting.  It could be batch-specific, or reflect a foundry problem to the track manufacturer.  Not much you could do to pursue it short of analyzing the rail systematically.  I doubt it is a precision metalurgical product, and cost pressures could have driven the manufacturers to lower standards in recent years.

[Ed Kapuscinski]

I personally doubt the grout or glue are the problem here.  I think the most likely problem is that there is a manufacturing defect, in the sense that there are some impurities in the composition of the rail alloy.  This could explain a localized problem on a given piece of rail or with particular batches, and the occurrence of rail oxidation in other situations besides what @Ed Kapuscinski is reporting.  It could be batch-specific, or reflect a foundry problem to the track manufacturer.  Not much you could do to pursue it short of analyzing the rail systematically.  I doubt it is a precision metalurgical product, and cost pressures could have driven the manufacturers to lower standards in recent years.

This is my exact thought.

I'm most perplexed about what to do about it though. I don't want it ****ing up my scenery, but I also don't want to relegate the case of it I have to staging use only.

[Scottl]

Some kind of oil coating on the entire rail surface like No-ox might prevent it.  After painting and weathering.

[Dave V]

I can't help but see this as yet another quality control issue Atlas code 55 has had owing to the low quality metal used in their Chinese factories. I remember being completely unable to solder a feeder to a code 55 frog in spite of my every effort and precaution.

[peteski]

I can't help but see this as yet another quality control issue Atlas code 55 has had owing to the low quality metal used in their Chinese factories. I remember being completely unable to solder a feeder to a code 55 frog in spite of my every effort and precaution.

That's likely because the frogs and point rails (N scale c55) are *NOT* nickel silver.

They seem to be made from a pot metal  core, copper plating over that and some mystery metal plating over copper.

[Doug G.]

It's COVID.

Doug

[Dave V]

That's likely because the frogs and point rails (N scale c55) are *NOT* nickel silver.

They seem to be made from a pot metal  core, copper plating over that and some mystery metal plating over copper.

Known on the periodic table as Chinesium.