Fix your Code 55 turnouts with Conductive Paint

[peteski]

Huge up-votes  for Max for doing the  thorough research, confirming my original suspicions (based on my electronics experience and common sense). 

One thing I'm puzzled about it how Mike's test strip of paint which he stated was roughly of similar dimensions to what Ed planned to do was had only coupler ohms of resistance. 

[Ed Kapuscinski]

I'm concerned about the longevity, but so far, voltage and amperage doesn't seem to be an issue.

At MOST there might be two locomotives pulling current through the connection, but most likely one, so we're not talking a ton of current draw.

I've checked all my applications with my RR Amp Meter so far and everything's been indistinguishable from the rest of the layout.
Am I missing something on that front?

[peteski]

I'm concerned about the longevity, but so far, voltage and amperage doesn't seem to be an issue.

Are you sure that the electrical  connection is through the conductive paint and not thorough the (possibly intermittent) original shunt inside of the turnout?

[Ed Kapuscinski]

Are you sure that the electrical  connection is through the conductive paint and not thorough the (possibly intermittent) original shunt inside of the turnout?

Not entirely. But I'll say this: after 20 minutes of applying it to both yard ladders, the intermittent contact issues I had before are gone.

I look at solving these issues as an onion, right? Obviously it's best to have the internal wiring working, but when that isn't, this is another layer of protection.

[peteski]

I look at solving these issues as an onion, right? Obviously it's best to have the internal wiring working, but when that isn't, this is another layer of protection.

Ah, adding a redundant path for the current. 

[mmagliaro]

Well, it's working for you because it is only solving an intermittent problem.  And I'll assume you know what you're doing, so you have
jumpers to lots of track sections, which means these carbon tracks only carry current for a fraction of a second while an engine
gets through the turnout. 

But if you really want to know "why"....
first I'd ask you to make a strip of carbon paint like that across a tie from rail to rail on a scrap piece of flex track that isn't connected to anything, and after it dries, measure the resistance across the rails with an ohmmeter.  That will tell us what resistance YOU are getting.  It might only be a fraction of an ohm.  Maybe you are putting it on thicker than it looks in the photo.

If you get an appreciable amount (say, 0.5 ohm or something), scratch out the carbon stuff (or use another piece of track),
and try the same experiment but this time, put a piece of bare stripped thin copper wire in there, so it goes most of the way from rail to rail.  Splotch the carbon goo right over it, using the carbon liquid to bridge the two gaps at either end to the rails.  Let it dry and measure THAT resistance.  It will be  whole lot less.

As for you noticing a voltage drop...
If only 1 engine pulls current through there, and it's a reasonably modern one, it's only drawing around 100 -150 mA, not a whole  amp.
.15A x 1 ohm = .15 volts.  You'd probably never notice it.   150 mA is a lot different than an amp.

I would still never depend on this.  One fun day if you have a short anywhere and it pulls your whole booster current through one of those, they could even catch fire, and I'm not saying that just to be scary.  I did a repair with that stuff on a pilot wheel on a loco for a guy once.  All worked great until he derailed it and the wheel lodged itself just right so it conducted the short path, and the carbon stuff carried the maximum track current.  It completely melted and destroyed his pilot truck in a few seconds. 

I'll shut up now.  I really am not trying to be a naysayer.  I just know from practical experience, and from what I know about electricity, that this is just not a good idea.

[Ed Kapuscinski]

Max, I now totally get exactly what you're saying. And yes, this works because it's ONLY carrying power for a TINY bit of track: maybe 2" of rail MAX on #10 switches, and that's only when the underlying contacts have failed. I wouldn't trust it for anything that I absolutely NEED to trust it for. But as another layer to the onion? I'm happy.

And yes, I've been a good boy and made sure to put feeders basically everywhere else.

I like the idea of the experiment, but I've got the rest of a layout to build (and "test")!

[peteski]

This has been a very interesting exchange of ideas.

[mmagliaro]

As luck would have it, I still had a tube of that BARE carbon based conductive gel that Ed is using from my earlier experiements.
I put a bead of it about 1/8" x about 3/4" on a strip of white cardboard, with copper wires stuck into the ends of it.
I let it dry thoroughly.

According to BARE's website, at 55 ohm per square, I had   3/4 / 1/8 = a length 6x the width, so the resistance should
be about 6x55 = 330 ohm for a 50 uM layer.  I'd guess my bead is more like 1/32", or 14x more than 50 uM.
So I should be getting 330/14 = 23 ohm. But I'm getting more like 220 ohm.
 
I tried the same test with MG Chemicals Nickel Print, which gave me 27 ohm and should be more like 2 ohms. 
--
Update: 24 hrs later, it is not really any better.  Still 200+ ohms for the carbon material, and about 20 for MG Chemicals Nickel Print.
Actually, the 20 doesn't surprise me because when I used to use it just to bridge a fraction of an inch on a Mikado wheel, I would get
under an ohm, but that was conducting just a tiny distance of not even 0.1 inch.

[peteski]

. 
--
Update: 24 hrs later, it is not really any better.  Still 200+ ohms for the carbon material, and about 20 for MG Chemicals Nickel Print.
Actually, the 20 doesn't surprise me because when I used to use it just to bridge a fraction of an inch on a Mikado wheel, I would get
under an ohm, but that was conducting just a tiny distance of not even 0.1 inch.

Max, I suspect that  Ed is not  very interested in your findings, since he is convinced that he found a great solution, regardless of the findings that would go against his "hack".

I was also surprised that @C855B 's results (in Reply #7), using the same conductive paint, were quite different than yours.

[mmagliaro]

Well, Ed may not have need of my blathering, granted.  But this is Railwire, after all, where open discussion is encouraged if it's not obnoxious.

As for my results, here's a video of a guy testing this stuff like I did.  He gets results like mine.  They are a little better, but the order of magnitude is the same.  In other words, for 1/2 inch of this stuff, we're talking  something on the order of 100 ohms, not 1-2 ohms, and in fact, he makes a point that the resistance is quite high and probably not something you would want to use to bridge a crack or cut in a circuit board.
https://www.youtube.com/watch?v=TOxOM-OEecA

You'll notice that all the BARE demos show LEDs lighting up, touch switches activating things, stuff like that.  They don't show it running an electric motor.  Believe me, I've been down the road with this stuff.  There's nothing wrong or evil about it.  But for carrying any kind of current it's not really up to the task. 

[John]

I think these hacks are good for temporary fixes .. but in the long run it's better to just replace of repair the turnout or component with the tried and true methods.

As far as the Atlas turnouts - we've had many examples here on how to repair them ..  I just tore down my layout and have started to refurbish track - I will take the opportunity to fix all my turnouts with PC ties in the appropriate places and replace closure rails when needed with a better mechanical solution

[peteski]

I'm surprised someone down-voted my last post.  Really? For stating what seems to be the obvious fact based on the earlier discussion?  Another accidental down-vote?  Don't think so.

[Ed Kapuscinski]

Well, Ed may not have need of my blathering, granted.  But this is Railwire, after all, where open discussion is encouraged if it's not obnoxious.

As for my results, here's a video of a guy testing this stuff like I did.  He gets results like mine.  They are a little better, but the order of magnitude is the same.  In other words, for 1/2 inch of this stuff, we're talking  something on the order of 100 ohms, not 1-2 ohms, and in fact, he makes a point that the resistance is quite high and probably not something you would want to use to bridge a crack or cut in a circuit board.
https://www.youtube.com/watch?v=TOxOM-OEecA

You'll notice that all the BARE demos show LEDs lighting up, touch switches activating things, stuff like that.  They don't show it running an electric motor.  Believe me, I've been down the road with this stuff.  There's nothing wrong or evil about it.  But for carrying any kind of current it's not really up to the task. 

Au contraire my friend!

I really do appreciate you "doing the math".

I think it brings up a real drawback to this approach that is absolutely worth acknowledging.

[wm3798]

I'm surprised someone down-voted my last post.  Really? For stating what seems to be the obvious fact based on the earlier discussion?  Another accidental down-vote?  Don't think so.

As an old communication major, I suspect it may have been your supposition of how Ed was responding to Max's experiment without any direct evidence from the immediate participants in that aspect of the conversation.  Since Ed has circled back and stated his interest and support of Max's work, it's probably best to just let it go.  As for the variations in the results?  Everyone is doing their experiments in their own way on their own time.  It's okay.

I have a ton of these turnouts salvaged from my old layout, stored now for almost 10 years, so I'm very interested in how they might be revived when that time comes.  I find it all very helpful.

Lee