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Starting my third layout and was thinking about the soldering of countless power drop leads to the rails.

I picked up this rather expensive silver-based conductive epoxy. What if one were to use the regular Atlas rail joiners but apply this conductive epoxy to the joiners and rails? We all know joiner connections are not reliable but could the epoxy eliminate that problem by ensuring a very good bond?

Thinking out loud not trying to re-invent the wheel!

Thanks.

Chuck

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I'm building my new layout now with Atlas... at the moment I have one (1) power feed to the O-72 loop which is 52' with *no* dips in power.  Of course more will be added.  I don't think I would use an adhesive... to messy.   Solder, maybe in hard to reach placements.

Am thinking of a very light application of the conductive adhesive. Toothpick in the groove of the joiner. Just enough to make a strong electrical bond to the rail without it being visible or barely so.

Personally, I think you're whistling in the wind.  IMO, no way that will be remotely close to as reliable as solder. However, as we're so fond of saying, it's your RR, and you get to run it any way you like!

After all the times that the power drop bug has bitten me in my track, as well as other people's layouts, that's not for me!  My layout currently under construction when all is said and done will probably have around 80 or so power drops for 400 feet of track.  The one thing I'm planning on NOT dealing with is power variations along the route!

Test it first... put a couple of pieces together and let it set overnight.  Then, pull it apart and put it back together and see how it goes.   You are probably a far better planner than I... I've made some considerable changes to my layout so far ...like busting through a knee wall to get an O72 loop.  There is one feeder on the loop...



There are about 30 feeders (10 each) in my O54, O45 loops and Yard so far... I'll probably have a similar number in the O72 loop.

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Last edited by Dennis-LaRock

Yep I'm going to run a test on this idea. Like you guys I have put in more power drops than I can count! Have never regretted the decision especially after a few years of running and the rail joiners start to get oxidized and/or loose.

The fact that this is a high-conductive silver epoxy it might just work.

If I'm wrong it certainly won't be the first time in this hobby!

Chuck

@Lionelski posted:

Soldering, with the right iron, is the way to go. Fast, inexpensive, and great conductivity.

Traditional lockons have been around for many, many decades - not pretty but don't pooh-pooh their use off the bat. The WVRR uses both methods.

Agreed. What is the reason that many rail joiners fail to conduct electricity over time? Loose or oxidation? Both I am guessing...

Going to try and test this silver-based epoxy today. If it locks in the joiner with great electrical conductivity it sure will be nice not to run wires and connectors under the layout.

I'll report back.

Chuck

It's not that it won't work for a short period, but what happens when several years pass and expansion and contraction starts happening at those joints? I've just stuck track together with the factory joiners and/or pins, and it works for quite some time, then gradually high resistance joints start showing up.

You're probably right about what happens, both loose and oxidized over the long run.  I just don't have a lot of faith that it'll be a long term fix.  If you have scenery in place and maybe ballast, it's a whole lot harder and more labor intensive to start wiring track then.  Just having conversation here, obviously the only way to really know if it's a long term fix is to wait long term.

I'm listening gunrunner that's what makes this hobby so fun.

I've used the silver epoxy on a rocket I built last year. Solder is great but I still get cold solder connections sometimes even when I try my best. Melted ties and all that even with heat sinks.

The rocket of course has higher vibration but the epoxy was excellent and I learned to trust it over solder. We'll see...am curious when I test this stuff what kind of connections it makes. It does prevent oxidation and looseness over time.

Check out my rocket!

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  • mceclip0

Since you are using Atlas track, here's another 'no soldering' method to power it. Pretty easy to do as well. Developed by forum member Ingeniero No1 (Alex) in his layout build thread. I tried it on my Atlas track 6 years ago and wired all track power like this. Works just fine.

This link has a pic and all the parts needed to get going Connecting Feeder Wires To Atlas Track

Here's a link to more pictures in Alex's build thread. Ingeniero No1's layout build Thread - He talks abou this in a few other places as well. And I would recommend looking at this thread, Alex had some other very good ideas for using Atlas track and also for building his layout in general.

Last edited by rtr12

You guys of course have great ideas many of which are time-tested as working.

Just bonded the rail joiners using a conductive epoxy and I will say I really like it so far. Won't test the strength until the morning. The epoxy worked it's way around the joiner and rail quite nicely and even came up through to seal the gap between rails.

I  used isopropyl alcohol to lightly wipe the top of the rail in case the epoxy got a little too high in the gap. The fact that it fills the gap is a good thing.

Can't tell at all  in the joiner that epoxy was applied. Used a toothpick. Will test the conductivity tomorrow.  This epoxy is made to be conductive and flexible. Unless I'm mistaken this might be a great way to power the rails without having to run all that wiring.

Chuck

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  • mceclip0

I have no doubt it worked the next day.  The problem with solid joints like that is when expansion and contraction takes place.  I used to jump tubular track with a spot of solder.  After months, or maybe even a year or two, the spot of solder would crack right in the middle from the two pieces moving relative to each other! Once I started soldering a short piece of wire between the two track joints, that never happened again.

I predict a similar fate for this fix.

I really hope this works out for you.  I tried basically the same thing back in 1968 with my HO layout.   At that time, the product was called "Solder in a Tube."   It was a total failure.

The product was just basically epoxy (with the thickness of toothpaste) with lots of ground silver or something mixed into it.    I was very gloppy to work with, gave uneven results, and didn't really help out with conductivity much.  It was very hard to get small amounts of it in place, and wanted to form globs.  And, getting oil or cleaner on it made it start to come loose.

Hopefully, after almost half a century of progress, the product you have is better.

But remember, epoxy is not immune to light oils and chemical cleaners.  They will work there way underneath it.  Acetone in particular will dissolve lots of epoxies.

Mannyrock

I appreciate the inputs. This is a silver-based epoxy designed for this type of environment.

The bond to the silver-nickel track is quite solid. No increase in resistance at all across the gap.

Haven't even started the benchwork yet so powering the rail is still in the future. I will probably run feeds anyway but maybe won't have to do it with each section as has been done in the past. I'm pretty serious about good electricity on the rail.

You guys need to come up with a prototypical welded rail that we order in 20 ft lengths.

Chuck

Been experimenting with the silver epoxy to join the rails at the joiners and bypass having to solder feeders to each section of track.

From a silver epoxy website: "The product is designed for conductive bonding applications in microelectronics in place of lead tin solder or other alloys to avoid flux contamination or exposure to excessive temperature, and for process simplification."

My experiments show that the bond at the joiners are rock solid. I tried all sorts of pulling/flexing and the silver epoxy held strong. No drop in resistance at all across the joints. It appears to me the silver epoxy chemically bonded to the silver in the rails? I'm not a chemist but it sure looks and feels like it did.

When done right I can't even tell the epoxy has been used. I did allow some to remain in the rail gap and it's almost like having welded rail.

Am going to power my new layout with this idea... if I turn out to be wrong then I'll solder feeders on in. But right now it looks like one could go quite some distance without feeders.

Thanks.

Chuck

I did expect some resistance (pun intended) to this idea.

I've soldered a couple hundred-plus feeders to the rails over the years. My goal is to avoid all the wire connections needed under the layout and the fact a soldered feeder can be seen.

My method takes about 2 minutes to join the rails and about 15 minutes of low heat from a heat gun to cure the epoxy. I like the welded-rail look and sound if one is going with a more modern era layout.

I don't want to drill into ties and all that either. If the track plan is changed then it's the dremel to the rescue.

My testing of the joint was quite thorough and I like the results.

Thanks for the inputs! So far you guys haven't swayed my decision. Silver-based epoxy is expensive but it's used all the time in critical electrical connections.

Chuck

FWIW, you can go quite a distance without drops with normal track pins of they're all done decently.  When I was laying out my track, I first laid all the track and just soldered the drops and dropped them through the table.  They were not connected anywhere, so all I had was track pin.  At the time I had over 300 feet of track down, and I was able to run all over the table with one connection from a PH180 brick!  The only exception was the lift bridge which obviously requires connections since there are no pins connecting it.  When I checked with a 2 amp load on the opposite end of a 24 x 12 layout from the single power connection, I had about a 1.5V power drop, not too bad for what I was doing.

Of course, now I have a total of around 60 power drops all over the layout wired in a bunch of home-runs to the power panel, I wasn't about to actually try to run that way!

If all of your joints are welded tight, I could see where that might cause issues with expansion and contraction with every change of the seasons. When this site first started up, I recall a member writing that he did not plan well for seasonal expansion and contraction and he had tight rail joints on a previous layout. He said his rail wound up spiraling out of the spikes on his curves. This member is a seasoned model railroader and I don't think he was making it up. It made an impression on me.

I put a utility knife blade width between every rail and left the joiners free to move. Some of the joints have still tightened up. I know others who have some varying issues with expansion and contraction on some large layouts. If I did weld or solder all the joints, I'd worry less about the joints breaking than the joints NOT breaking.

I soldered a feeder to every rail and used a resistance unit with the resistance tweezers which made it pretty neat and easy to solder to the backs of the rails.

Just something to consider.

Good luck.

Last edited by christopher N&W

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