03-14-2009, 07:37 PM
I enjoy reading threads like this, because I learn trying to figure out explanations for the results.
My ideas - put together from experience and experiences of others:
Metal rail oxidizes in the presence of oxygen (naturally!). High humidity and high temps tend to accelerate oxidation, as does the presence of salts (dissolvable compounds) in the air. If you don't believe me, go to sea in the Gulf Stream and try keeping the brass shiny.
Brass, iron, and steel oxides do not conduct electricity. Nickel silver oxide, although sort of conductive, will cause noticeable performance issues with our model locomotives due to voltage drops through the increased resistance.
Sparking also causes spot oxidation and pitting. The heavier the current, the worse the oxidation and pitting is.
How to get rid of oxide:
1) frequent passage of locomotives and cars, the heavier the better. This works well in the larger scales, and excellently for the prototype. The metal wheels "polish" the rail as they roll over it, and cause the weaker metal oxide to break up and fall away. In HO, running trains at least 3 times a week on brass track kept the oxidation issue at bay for me in Northern Virginia, even with no air conditioning during the summer.
2) Which leads to method #2, using an abrasive on the rails. This method works, but leaves the metal raw, minutely scratched, and available for fresh oxidation. Sparking always seems to be at a maximum when rails are totally dry, clean, and unpolished.
The other methods leave some form of coating on the rails.
3) Wahl oil is the subject of this thread. It is a conductive oil that seals the rail head to help prevent oxidation from reoccurring. But too much can impact traction (pulling power) negatively, and it also causes traction tires to no longer work/fit correctly. I would lump the old standby of No-Ox into the same category.
4) Graphite works in much the same manner as the Wahl oil. My concern with graphite would be the mess, and the blackening of the railhead. The prototype rail top, starting with the inside corner, is nice shiny, polished steel.
5) Another group swears by CRC-226. It is basically an electrical contact cleaner and lubricant with water-displacing solvents. Again, a conductive coating is left behind when the solvents evaporate. The solvents probably will chemically dissolve the oxide, too. FWIW, do not use WD-40 (Water Displacement Formula 40). WD-40 solvents dry into a sticky mess. The lubricating qualities are in the solvents, not the base, so that when the solvents turn sticky you no longer have any lubricant.
6) Another group swears by burnishing and polishing the rail with metal polish. The burnishing helps reduce the scratches and nicks which increase oxidation and dirt collection. The polish serves as the protective coating to prevent re-oxidation.
And of course, running trains frequently - heavy trains with metal wheels - is a great way to enjoy your layout and clean the track at the same time.
Fred Wright
...modeling foggy coastal Oregon, where it's always 1900....
My ideas - put together from experience and experiences of others:
Metal rail oxidizes in the presence of oxygen (naturally!). High humidity and high temps tend to accelerate oxidation, as does the presence of salts (dissolvable compounds) in the air. If you don't believe me, go to sea in the Gulf Stream and try keeping the brass shiny.
Brass, iron, and steel oxides do not conduct electricity. Nickel silver oxide, although sort of conductive, will cause noticeable performance issues with our model locomotives due to voltage drops through the increased resistance.
Sparking also causes spot oxidation and pitting. The heavier the current, the worse the oxidation and pitting is.
How to get rid of oxide:
1) frequent passage of locomotives and cars, the heavier the better. This works well in the larger scales, and excellently for the prototype. The metal wheels "polish" the rail as they roll over it, and cause the weaker metal oxide to break up and fall away. In HO, running trains at least 3 times a week on brass track kept the oxidation issue at bay for me in Northern Virginia, even with no air conditioning during the summer.
2) Which leads to method #2, using an abrasive on the rails. This method works, but leaves the metal raw, minutely scratched, and available for fresh oxidation. Sparking always seems to be at a maximum when rails are totally dry, clean, and unpolished.
The other methods leave some form of coating on the rails.
3) Wahl oil is the subject of this thread. It is a conductive oil that seals the rail head to help prevent oxidation from reoccurring. But too much can impact traction (pulling power) negatively, and it also causes traction tires to no longer work/fit correctly. I would lump the old standby of No-Ox into the same category.
4) Graphite works in much the same manner as the Wahl oil. My concern with graphite would be the mess, and the blackening of the railhead. The prototype rail top, starting with the inside corner, is nice shiny, polished steel.
5) Another group swears by CRC-226. It is basically an electrical contact cleaner and lubricant with water-displacing solvents. Again, a conductive coating is left behind when the solvents evaporate. The solvents probably will chemically dissolve the oxide, too. FWIW, do not use WD-40 (Water Displacement Formula 40). WD-40 solvents dry into a sticky mess. The lubricating qualities are in the solvents, not the base, so that when the solvents turn sticky you no longer have any lubricant.
6) Another group swears by burnishing and polishing the rail with metal polish. The burnishing helps reduce the scratches and nicks which increase oxidation and dirt collection. The polish serves as the protective coating to prevent re-oxidation.
And of course, running trains frequently - heavy trains with metal wheels - is a great way to enjoy your layout and clean the track at the same time.
Fred Wright
...modeling foggy coastal Oregon, where it's always 1900....