That black gunk from nowhere that plagues model railroaders has finally been figured out. It is caused by micro-arching between the wheels of powered locomotives and the track on the inside of the track where the flange meets it. This is shown in fig. 1.
The author’s background is in Chemistry and he understands that in order to prevent the gunk in the first place you have to prevent the micro-arching. The only way to do this is to clean the track and wheels with a liquid that has a low dielectric constant meaning it is a non-polar solvent. You don’t really need to understand what that is. All you really need to know is that lower dielectric constants prevent arching and which solvents have a low dielectric constant.
The table on the left (thanks to Model Railroad Hobbyist Magazine)
is a list of many solvents that most readers should be familiar with. The
key to this table is that the solvents are listed from the lowest dielectric
constant to the highest.
So what solvent is the most commonly used by
model railroaders that have never heard of dielectric constants? Would you
believe Isopropyl alcohol? Look at table 1 and find Isopropyl alcohol (commonly
known as IPA). What is its constant? How good do you really think it is at
keeping track clean? Are you still cleaning a lot?
There are some solvents to definitely not use (common sense) Kerosene, Gasoline (explosive), Carbon Tetrachloride
(carcinogenic) are just some of them. Mineral Spirits is a good choice because
of both its low dielectric constant and its cost. It also comes in an odorless form.
The author has tested several of the low constant solvents on his home layout with these results.
WD-40 contact cleaner - inexpensive but dries much too quickly making it difficult to clean engine wheels. Also recommends good ventilation (toxic).
CRC contact cleaner - Plastic safe but expensive and has multiple warnings of highly flammable spray.Also dries too quickly.
Gasoline, Kerosene & Diesel - forget it (you figure it out)!
Mineral Spirits (odorless) - inexpensive and readily available. The author is currently testing this on his home layout.
By the way, he has also gotten rid of his IPA except when laying
ballast.
Addendum 2025-07-13
There has been some pushback concerning the use of oderless mineral spirits for cleaning track and wheels. Along with these arguments against its use is the author's response. Do your research first before spouting off that you know better.
IT'S FLAMMABLE
The flashpoint (the temperature at which a substance will easily ignite if exposed to a spark or flame at or above this temperature) of Isopropyl Alcohol is 64 - 75 degrees F while the flashpoint of oderless mineral spirits is 100 - 140 degrees F. Which do you think will flash first?
IT DAMAGES THE PLASTIC OF LOCOMOTIVES
What are you doing, putting it on with an air brush? Use common sense. To clean track put it on a small felt pad and clean it. For locomotives the author removes some sheets from a alcohol wipes container, let's it dry out in open air and then puts OMS on it on a test track and runs a locomotive, holding it still, to clean it's wheels. It's not that difficult to figure out.
IT DAMAGES SCENERY
See the above remark.
As the author said above, it's not difficult to use, it's not dangerous, it not damaging (common sense, remember?) and it cleans better.
Bryce R (sorry don't know the last name) has uploaded to the LokSound groups.io files section several Nathan P and M type horn sound packs. These apparently would be very useful for Southern Pacific fans. An example horn pack is shown in figure 1. You can get to them here.
If you are not a groups.io member it's easy and free to join. Read the second paragraph of this post to see how easy it is to join.
If you have an idea for a blog post here, let me know. If I can comment on it, I will or I'll see if someone else can and post it.
This update will not be available by auto-download for a week or two.
The LokProgrammer software 5.2.13 is now available for download. This includes the firmware 5.12.178 for all LokSound 5 and LokPilot 5 decoders: It allows for higher motor current when start moving to "kick off" some heavy trains more easily.
Further, new decoders such as ESU Digital interior lighting strip 2.0, LokPilot 5 micro DCC Direct Atlas Legacy or Lenz LenS5 L decoders are now supported.
In the decoder's motor setting, there is now an additional diagram showing the actual speed table values as computed and used by the decoder. This is for easier speed matching.
Atlas will be closed for vacation from July 4th through July 11th. Orders will be processed when the office reopens on July 14th.
Please have orders in by Wednesday, July 2nd at 12PM ET to ensure shipping before vacation.