# Testing Dirty vs. Clean Track -- Technical Question



## Jim Cubie (May 26, 2015)

I have been surprised that I have been unable to find any systematic assessment of track cleaning methods. There's lots of "it works for me" but no comparison based on any testing. I am setting out to determine whether one can use a multi-meter (or other tester) to compare dirty-to-clean track. My basic question is whether you experts thank that the approach I am taking produces meaningful results. Fortunately I have multiple pieces of dirty flex track available so I can test various testing options.

First, I took a piece of dirty track and divided it into 3 sections. One third I cleaned with an alcohol soaked rag over a block of wood, a second I cleaned with goo-gone, the third I did not clean. There was dirt on the rag where I cleaned it so I know that the track was in some sense "dirty." I could find no measurable difference in amps or volts when I compared the 3 sections. There did seem to be a difference in resistance as measured in tenths of ohms.

I then took 10 pieces of track and divided it into clean and dirty sections and tested for ohms. I found that the resistance on the dirty section was typically 0.3 ohms greater than on the clean section. ( the measurements were usually in a range spanning a few tenths of an ohm, as an example "0.6-1.0 ohms.

Do you think that these results are meaningful? Is there a better way to do it. I will email more details on how I did the tests if you are interested.


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## DonR (Oct 18, 2012)

There could be marginal meanings to your resistance readings for
DCC decoders and perhaps lighted cars. We all want clean tracks
because they do provide better conductivity, but it seems that most
of us have been successful using a track cleaning car with
alcohol, or one of the other suggested solvents. Or simply use
a rag and alcohol, and a kitchen cleaning pad. You do have
to be careful when using a rag on the track. It can catch on
turnout and crossing points and may damage them. The pad
on my track cleaning car seems to glide safely over them,
however. You can see that it is being effective by the dirt
stripes that appear on the pad during use. A typical pink
pencil eraser is also effective to remove track dirt.

Another factor is changing wheels from plastic to metal. The metal
wheels don't collect gunk on their treads as does plastic. If it's not
on the tread it won't be transferred to the rail heads.

To me, the most important conductivity factor is having sufficient
track drops to a power buss. If the track voltage is constant around
the layout the minor differences in track cleaning methods would
be meaningless.

Soldering track joiners is another plus factor for constant conductivity.

Don


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## CTValleyRR (Jul 26, 2014)

Actually, it doesn't surprise me at all. Track cleaning is basically an "If it ain't broke, don't fix it" process. Most of us don't want to spend agonizing efforts cleaning track, so when we find a solution that works satisfactorily with a minimum of effort, we use it, and are disinclined to change.

There is no silver bullet to track cleaning. If there was, we'd all use it. Sure, you can determine an empirical "best" method by establishing some standard (it sounds like you're going for resistance), but if I don't see any noticeable change in performance from one method of cleaning to another, why should I care whether a given method reduces resistance by 0.29 ohms or 0.31 ohms?

My standard for cleaning is how often do I have to do it, and how long does it take. I have my track down to where I only do deep cleaning after making changes, painting rail, or working on scenery nearby. Otherwise, one lap with a track cleaning car (Masonite pad covered with a cotton cloth moistened with denatured alcohol) before every session does it for me. When I get my larger layout built, I may have to re-moisten the rag, but that's about it as far as changes go.

All you have proven by your experiments is that clean track conducts better than dirty track, and that's pretty much a no-brainer for anyone who's been in the hobby for more than a month. For me, this is a purely academic interest, and I certainly wouldn't bother to invest the time and effort necessary to conduct these experiments.


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## rkenney (Aug 10, 2013)

How are you measuring resistance (not the tool, but the method)?


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## D&J Railroad (Oct 4, 2013)

I'm not sure what you are expecting to find. Maybe a difference in voltage on the rail head of .0034 volts or so. What is that going to do for ya? When ya consider the hit and miss action of track cleaners, you're not going to have the same cleansing effect across your whole layout, so there goes the difference between cleaning devices. 
If you want a track cleaner, just pick one that has been mentioned here and go with it. If you're looking for some deep scientific explanation or thesis study, I don't think you're going to find it here or anywhere else.


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## fcwilt (Sep 27, 2013)

Sometimes what stops a train is a bit of crud that lifts the wheel(s) off the track.

I don't believe that measuring resistance is going to really reveal anything.

When I have trouble with trains stopping I run a cleaning car around the circuit a time or two and all is good again.


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## mikek (Dec 29, 2013)

I understand the desire to measure and document model train activity. What I would do is pick an illuminated coach or a spotlight car or such and push it around the track by hand with the power full on. The intensity of the light will give you a good idea of what's happening with your track, and give a good show of what improvements work best. I know I have a couple of bad spots in my test track, my cars blink at the same places.


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## rudy's railroad (Nov 14, 2015)

The tin rails along with the "other" metal alloys used to make them conductive and structureally capable to withstand a somewhat "physical load", naturally produces, if you will, its own "dirt". At some point, dependent on the physical compisition of the wheels rolling on them which produces friction, will inherently leave residual.


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## gregc (Apr 25, 2015)

Jim Cubie said:


> I found that the resistance on the dirty section was typically 0.3 ohms greater than on the clean section. ( the measurements were usually in a range spanning a few tenths of an ohm, as an example "0.6-1.0 ohms.


presumably you're looking into this because your have problems with locomotives stopping. Considering that a locomotive can operate at much less than full voltages, 12V, 1 ohm of resistance in the path of a motor drawing even as much as 0.5A will only drop the voltage by 0.5V and is unlikely to cause a loco to stop. Any drop in rail voltage should have less of an effect with DCC.

however, the rails are just one contact

I've puzzled how an an 0-6-0 has no power with 3 wheels on the locomotive picking up power from one rail and 4 wheels on the tender picking up power on the other rail. In the tender, each wheel needs to make contact with the truck, each truck with the brass tender floor and then there is a contact point on the drawbar at both the tender and loco.

Somehow, each contact point can open, passing zero current. Drawbar contact is obviously critical. And weight also affects contact on the wheels and truck/tender floor.

it appears these contact points can easily drop out, which is one reason keep alives can be so effective.

locomotive wheels seem to have fewer problems Perhaps because the only contact point is between the wheel axle and frame, besides wheel contact with the rail. The locomotive is also heavier.

i've had success adding contacts to the locomotive wheels on the opposite rails by adding copper contacts to the wheels, minimizing the multiple tender contacts points.

of course this is different for a diesel which may have fewer wheels to draw power through.


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## Shdwdrgn (Dec 23, 2014)

It might be interesting to build a special-purpose car with an arduino onboard and a limited number of pickup wheels. Add in a strong keep-alive to ensure the arduino itself maintains power but monitors the track power separately, and then record the voltage as the car moves around the track (rather than just checking with the multimeter at certain points). I would image dirt on the track would create a very noisy voltage pickup that could be recorded by the arduino and might help point out potential trouble spots?


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## Lemonhawk (Sep 24, 2013)

As far as resistance through the rail I would expect to see something very small, it's the pickup resistance that would increase. So did you use an Ohm meter from the rail to the motor or decoder input or did you just measure the from one end of the rail to the other?


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## gregc (Apr 25, 2015)

Shdwdrgn said:


> It might be interesting to build a special-purpose car with an arduino onboard and a limited number of pickup wheels.


Dynamometer Car.

but i think the resistance of dirty track causing a loco to stop is essentially infinite


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## Djsfantasi (Mar 19, 2019)

Cleaning the track isn’t enough. You need to clean everything that comes in contact with the rail head. Otherwise, your dirty wheels will redeposit crud immediately after you clean the track. 

#1 step in any program. Get rid of ALL plastic wheels. 

#2 Make a schedule to keep your wheels clean. I’d pull them and clean each wheel set with alcohol and a Q Tip. Really dirty wheels need light scraping with a small screwdriver 

#3 identify ALL points of contact in the distribution of power. Wheel wipers on locos and lit cars can also get crud caught between them. Not as much as a problem as with wheels, because the wiping action is self cleaning. But check it. 

#4 Clean the track. I used a rag moistened with alcohol or Goo Gone on my index finger and wiped each and every rail. Occasionally, I’d use Oops. 

Other considerations include installing an air filter in your train room. Or checking the track level. If one rail dips below the other, contact is poor and in the small space, crud will collect. This is common and often missed because people are focused on dirty track itself. 

Bottom line, you need to invest in finding out WHY the track is getting dirty and correcting the problem. If you take this approach, you’ll find that cleaning the track isn’t necessary as often.


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## Lemonhawk (Sep 24, 2013)

I like the idea of dyno car, gregc. That would make a great arduino project. It might be able to spot trouble area long before the cause real trouble. I'll have to read the article. Sounds like a fun project. Be even more interesting if could correlate the problems to a display of your layout.


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## Shdwdrgn (Dec 23, 2014)

gregc said:


> Dynamometer Car.
> 
> but i think the resistance of dirty track causing a loco to stop is essentially infinite


Very nice! And of course it's Geoff, seems like he always has something going that I'm interested in.  I like the idea of using a load cell (which is what I used in my scale track project), would love to figure out how to make a smaller one that could be mounted to the coupler of the loco to indicate when you have coupled or uncoupled a car (or lost some on the mainline).

I wasn't meaning that dirty track would cause a loco to stop, but rather using the measurements as an indication of HOW dirty each section of track is. You could use that as a warning to send a cleaning car down a particular branch, and it could be helpful in setting up a regular cleaning schedule.


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## 65446 (Sep 22, 2018)

SIMPLE: Take a known to be fine-running loco. Power the 3 sections. Run loco. If it stalls take loco off rails. Clean the area it stalled. Run loco again. If it doesn't stall in same area, you have a cleaner which works..
All the liquids and gadgets which are known to clean track, do just that,... clean track..
Why all the serious testing to see which is best ? One layout's cleaner is another layout's waist.
Clean your track and loco wheels with sumpin', anyting, and fuggeddaboudit !


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## mesenteria (Oct 29, 2015)

telltale said:


> ... One layout's cleaner is another layout's waist.
> ..





My waist keeps getting bigger, and increasingly in the weigh.


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## Lemonhawk (Sep 24, 2013)

Just cleaning the track isn't the idea. It's the project to detect and map where to service the track -- more "prototypical"


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## Shdwdrgn (Dec 23, 2014)

How about after the dynamometer car detects especially dirty track, you send out a crane and support cars which are secretly track cleaning cars? Camp out in an area for awhile doing a deep scrub of the track, then pack up and return back home. I know there are different 'types' of track cleaners, maybe you could have one car for the quick pass down the line, and something that scrapes the track for the really bad spots?


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## 65446 (Sep 22, 2018)

mesenteria said:


> My waist keeps getting bigger, and increasingly in the weigh.


Did you mean weigh, way, or whey ? :dunno:


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## gregc (Apr 25, 2015)

Lemonhawk said:


> Just cleaning the track isn't the idea. It's the project to detect and map where to service the track -- more "prototypical"


what about a track cleaning car followed by a measurement car?

if there's a section that's still dirty, run it back a forth a few times until the measurement cars says it's good.

not prototypical, but you don't waste (or waist) time cleaning track that's already clean


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## rudy's railroad (Nov 14, 2015)

Hello,

So I have a Lionel prewar 313 Bascule bridge I keep debating about restoring. My two biggest concerns are:
How do I clean the rails?
How do I clean the bakelite rail deck and base?

Any suggestions?

Thank you!

Rudy


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## rudy's railroad (Nov 14, 2015)

Last week I went ahead and started the process.
The entire bridge is now dismantled and the restoration is in process. I removed the rails from the deck and after several different attempts to clean, I finally figured out the best approach and they came out looking quite nice. 

i initially started with a crumpled up ball of aluminum foil rubbing against the rails. It did remove quite a bit of the rust. I followed that up soaking in white vinegar for a couple of days. That didn't do anything. Rinsed off and applied a water based paste using Bar Keepers Friend cleanser with gray scotchbrite. Rinsed off and went to dry red scotchbrite, finishing them with the crumpled up ball of aluminum foil. They look almost new.

Once the entire bridge is finished, I will compile my step by step process with photos start to finish.


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