Rail cleaning problem

[The_Ghan]

A strange thing has happened this week: I was doing some maintenance on my rail base and parts of my track turned green!

A 1m long piece of incline came loose, so I glued it with a water-based wood glue.  New polystyrene was glued to the MDF base and the cork underlay glued to the polystyrene.  My track was still in place on top of the 3mm cork underlay.  My track is Peco set-track.  To hold everything in place I rested a couple of small boxes on top of the track, each about 1' long, 6" wide.  I left it from Sunday afternoon to Wednesday evening.  The bottom of the boxes has the normal clear celotape used on shipping boxes.  Where the rails was in contact with the celotape they have become tarnished.  Not just on the top, but also on the sides.  I was surprised that this amount of tarnishing (olive green) should occur so quickly.  This is an underground portion of my layout and looks don't matter but - the rails turned green.

How do I clean this up?

Cheers

The_Ghan

[keitaro]

metho? lol

no idea to be hohnest.

[inobu]

That may be a form of corrosion which may be bad in the long run. I remember that some rails are nickel plated and some are not but you may have inadvertently created a little science project.  

I know that there is a link......................

Corrosion is an electrochemical process in which a metal reacts with its environment to form an oxide or other compound. The cell which causes this corrosion process has three essential constituents: an anode, a cathode and an electrolyte (electrically conducting solution). The anode is the site at which the metal is corroded; the electrolyte is the corrosive medium; and the cathode (part of the same metal surface, or of another metal surface in contact with it) forms the other electrode in the cell and is not consumed in the corrosion process. At the anode the corroding metal passes into the the electrolyte as positively charged ions, releasing electrons electrons which participate in the cathodic reaction. Hence the corrosion current between anode and the cathode consists of electrons flowing within the metal and ions flowing within the electrolyte.


the glue could have formed as the electrolyte to start the corrosion process.


Based on all the elements the clean up should be like your car battery terminal - water and baking soda.

Inobu  

[The_Ghan]

Hmmm ....

Having had bad experiences with humidity on my old OO gauge, and being located in Australia, I've been careful to set up a low-humidity environment for my N gauge project with air conditioning and several bucket-sized Damp Rid kits around the room, which I replace regularly.  Generally, there is no mould or corrosion except for that which I've mentioned here, which is quite green.  The corrosion has only occurred where the celotape was in contact with the rails. 

Lesson 1: Do not put celotape in contact with the rails;

The glue is water-based and was not in contact with the rails or track-parts directly.  Across the 1m length of polystyrene that was glued I would say 8-10 pea-sized droplets were used.  That said, it is reasonable to presume that some evaporative from the glue might have been involved.  However, the corrosion is restricted to beneath the celotape.  I'm going to leave a rail off-cut under the box over the weekend and see how it looks around Tuesday.

Cleanup:  Water and baking soda?  I'll give it a go!  I'm going to have to pull 4 point motors off those Peco turnouts.  The bits of track in between I might just replace if they don't clean up quickly.

Thanks for the tip.

Cheers

The_Ghan

[rpierce000]

What kind of glue was it? Will the celotape dissolve in it?  If so, the fumes from the glue may have either been trapped under the celotape and deposited on the rails or the celotape dissolved slightly in the fumes and that is what caused it.

I just took a look at nickel oxide on Google images and it is definitely green. I would guess that whatever fumes you are dealing with either produced VERY localized humidity or pitted the tracks at the microscopic level to exponentially multiply the surface area, allowing water to bond in a lot of locations at once. I knew that chemistry would come in handy somewhere...

Either way the baking soda will help, as will a track eraser, but if it is truly pitted it will never stay clean again. You will have to replace it. You will find out after the first couple of cleanings. If it turns green again quickly, it always will.

[The_Ghan]

Thanks Bob,

Aquadhere - it is a water based PVA wood glue.  The sort of thing you use for basic woodworking.  I wasn't expecting it to react with anything.  We shall see how the cleaning goes.

Cheers

The_Ghan