Moisture destroys Unitrack

[stevenh]

Yeah yeah, would've been obvious for everyone else... but I hadn't thought of the issue at all.

 

The scenario was this:

1. Buy glass table from op-shop and paint it. Really nice wooden-framed 810x810mm job, great for a loop-the-loop-the-loop.
2. Start planning/building/buying a layout.... 
3. Build the foundations (foam is great for inclines and fill.)
4. Make sure the track will be level, test run with all my low-floor trains. (Even the 300Kei Shinikansen ran!)
5. Start the plaster work for scenery.... Used Woodland Scenics products... worked really well.
6. Tuck the layout (with track gently placed on top of slightly-wet scenery) back into the table to 'dry' overnight.
7. ... wake up in the morning and see a gold-tinge to the track.

 

Of course, there were locomotives in there too... which now run like absolute crap!

 

The apartment I live in has never breathed well, but the table breathed worse.

I didn't realise how much moisture was still in the plaster. It still felt damp 3 days later :(

 

I then googled how to clean Unitrack and it came to a thread on this forum. How ironic.

 

Either way, it'll be a fun job when I get home... I do have a can of Brasso and will try that first. I'll also post pictures here to show the damage I've done.

 

I'll also then post a full construction thread... it's a fun layout!

[Ochanomizu]

Hello Mr stevenh,

 

If you search for "humidity" in this forum you will find many warnings ... ;)

[Mauka]

Aloha Steven, 

 

Thanks for posting this, my indoor and outdoor climate can also be very humid, and also adds salt air to the mix. 

I went with Kato Unitrack because of the Nickel-Silver construction, but have not built a permanent layout yet. 

 

Please keep us posted on your outcome.

 

Alan 

[cteno4]

This has been an issue for some. Personally ive never seen kato unitrak corrode at all. Some though have had some corrosion of kato and tomix track, sometimes a blue green. Nickel-silver should be pretty corrosion resistant, used in marine environments. I often wonder is there are inconsistencies in batches of nickel-silver that lead to some track with a susceptibility to corrosion. 

 

A few years back after some of these reports i tried an experiment with a couple sections of unitrak where i soaked one in water for a week and the other in a damp rag for a week (to simulate 100% humidity but let in more O2. nothing showed up as any sign of corrosion with the mag glass once air dried and put it in a loop and no noticeable running difference with a single truck switcher going over them. might take months and months to do it and ions as well, but was not into getting into a huge experiment!

 

cheers

 

Jeff

[Vato]

I have kato unitratrack around 5 years, but nothing happened (in New York we have high humidity)

[stevenh]

I don't believe humidity is really the key, it's that the moisture (would've been a cold temperature actually) was locked in the glass table.

I tried to take a pic last night, but the indoor night lighting didn't bring up the colour differences enough.

 

I'll take a photo when I get home today.

Meanwhile, bought a track cleaning brick from Woodland Scenics... worked a treat... but the sides of the rails still have a golden tinge to them.

[cteno4]

Well humidity is moisture suspended in the air. Even in cold temps it can hold moisture too. All the moisture in the enclosed space just saturated the air and thus all the surfaces with moisture. Only thing used was plaster around the track?

 

I wonder if its the sulfite in the plaster causing this or some other setting accelerant used by ws. Sulfur and acid can attack the zinc in ns. These odd corrosive events show up now and then but it seems pretty rare as ns is made to be pretty resistant stuff.

 

Alway good to have more data! Sorry this happened to you. Good to keep stuff like this to allow it to dry out well. Water is actually released when plaster sets up.

 

Jeff

Edited October 10, 2013 by cteno4

[katoftw]

I think you hit the nail on the head there.  The evapouration from the plaster will be carrying some other chemicals that most likely reacted to the metal track.  I'm no metallurgist so I cannot give you a great insight into it.

[stevenh]

Makes perfect sense... just wish I'd thought of it sooner...

 

Here's a little evidence. First pic shows a new piece of track out of packet vs. track that was on layout.

Second shows a little chunk of 'reaction' that's only appeared last night!

 

[cteno4]

Yeah I think it's salts from the plaster that must be doing this along with the saturated humid air.

 

Might try cleaning with some vinegar, ns is very good with organic acids. May need to buff with a roto tool. Some have found silver cleaning pads effective to clean off the gold tarnish. Experiment some.

 

Jeff

Edited October 11, 2013 by cteno4

[Ochanomizu]

Hello Mr stevenh,

 

So sorry, but the problem depicted in your photographs is related to humidity.  The water vapour in the air has condensed on the cool metal rail.  You will find the corrosion worst at or near the junction of different metals where one metal, usually the more ferrous, has become a sacrificial anode.  This process can be exacerbated by running electrical current through the metals.  It is a phenomenon well understood by electrical engineers, especially those involved in the design of micro devices.  To prevent this from occurring again please keep the relative humidity in the enclosure below 60% and minimise the change in diurnal temperatures.  Stabilizing the environment in this way will also prevent the growth of mould and fungi.

[cteno4]

I don't think this corrosion was due to water. Ns is pretty resistant to that. Unless it were iron contacting it I doubt there would be that amount of electro corrosion occurring in a few days and he was not running any current thru it. Looks like it was there on the layout in which case no direct dissimilar metals and I doubt enough conductivity to do much with other metals on the layout in the short time he had it there. I'm really thinking it was the sulfur or other ions in the plaster sometimes used to speed hardening in the plaster that was distributed by the humidity and condensed moisture that made the tarnish and corrosion this fast.

 

I could not get any noticeable tarnishing with unitrak immersed in water or in 100% humidity in a week. Now curious to take it out much longer and try one with some dilute salts.

 

Locos I can see having issues faster with moisture as they are a lot of dissimilar metals as well as many metals not so resistant to corrosion.

 

Jeff

Edited October 11, 2013 by cteno4

[Pspiropoulos]

Are you using Kato unitrack? I can't tell from the picture. High quality track like Kato and Peco is not subject to more than very minimal and very slow corrosion because the nickel silver content is high. If it is a cheaper brand, the nickel silver content is much lower, and brass track especially are both subject to fairly quick corrosion. High moisture content on the layout and in the air will exacerbate the problem. Though I'm not sure, I believe I've seen where Kato says they coat their rail with a conductive seal to reduce corrosion even more.

[katoftw]

Are you using Kato unitrack? I can't tell from the picture. High quality track like Kato and Peco is not subject to more than very minimal and very slow corrosion because the nickel silver content is high. If it is a cheaper brand, the nickel silver content is much lower, and brass track especially are both subject to fairly quick corrosion. High moisture content on the layout and in the air will exacerbate the problem. Though I'm not sure, I believe I've seen where Kato says they coat their rail with a conductive seal to reduce corrosion even more.

1. the thread title says unitrak, know any other brands that sell unitrak labelled products?

 

2.  the unijoiner in the picture really gives it away that it is a kato product.