# Track gap too wide?



## Overkast (Jan 16, 2015)

Hey all, need some advice. I always join my tracks with a space for rail expansion, but I have a space which I'm concerned might be too wide. Take a look and let me know what you think:









In contrast, here's what I consider to be more of a normal gap:









Trains run fine over the gap right now so it doesn't seem to affect the wheels, but I don't know if it's alway going to be fine and something I can just leave alone. Thoughts?

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

Fill it with solder.


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## Overkast (Jan 16, 2015)

Yeah I was trying to avoid solder at this spot but that might be the best way to go. I certainly don't want to have to cut out a small section of track and re-lay, just for this...

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## DonR (Oct 18, 2012)

When I end up with a gap like you have, I
cut a sliver of rail and use it to fill in. I can
usually twist it so it will fit into the joiner slot.

Don


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## Overkast (Jan 16, 2015)

That just might work Don, good tip! I'm working in N Scale though, so when you say "sliver" it will literally be a very tiny piece for each gap. The only challenge I may have is trying to grip such a small piece while getting a good angle to file down the cuts from the rail cutter tool...


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## santafewillie (Feb 13, 2016)

I have used pieces of styrene CA'd into the gap. After painting the rail, you can't tell the difference. Use an old piece of sprue and file it into a "T" shape; then you don't have to twist to get it into place. 
Willie


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## mesenteria (Oct 29, 2015)

On tangent track like you show, it's not a problem at all. It's a cosmetic thing that's drawn your eye, and will continue to bug you until you rectify it somehow.

I have used tiny clippings of the same rail material held in place and soldered. Works like a hot damn. Especially if you go to wiggle it to see if it's solid before it cools.


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## Overkast (Jan 16, 2015)

Thanks all for the ideas. I may try to do the tiny metal rail piece approach but see if I can get it to work without soldering the joint altogether. I like the idea of filling the gap with a conductive piece rather than a non-conductive (styrene) piece.


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## jlc41 (Feb 16, 2016)

Overkast, I'd go with peace of plastic as suggested it would probably be much easier (you a conductive rail joiner). However like they say it's your RR do what makes you happy.


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## Shdwdrgn (Dec 23, 2014)

Would it be possible to drop a bit of silicon over the rail, then when it hardens cut it with a knife to follow the profile of the rail? N-gauge probably requires a good lens to see the fine detail, but if it worked you would have a flexible gap that still holds the car wheels in place.


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## 3.8TransAM (Jan 13, 2016)

Why don't you just use a piece of .020, .030, .040 etc styrene as an equivalent while laying track so you keep the sizing the same on the gaps?

Butt and go, butt and go


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## Overkast (Jan 16, 2015)

3.8TransAM said:


> Why don't you just use a piece of .020, .030, .040 etc styrene as an equivalent while laying track so you keep the sizing the same on the gaps?
> 
> Butt and go, butt and go


Ha... great idea TransAM, but all my track-laying is done at this point. Next layout maybe??? 

Thanks for all the suggestions. I am going to consider them all, even the soldering. I think mesenteria is correct though, considering the trains run just fine over the gap and it is a tangent track, it's probably not a real concern for derailment but rather more of a cosmetic thing that's just going to bug me until I do something about it.

I am going to try in this order:

Small cut pieces of rail, if that don't work then...
Styrene, and if that don't work then...
Silicone, if that don't work then...
Solder the gap.


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## Lemonhawk (Sep 24, 2013)

Here's a picture of using styrene to fill the gap, after its been cut to conform to the rail.


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## gregc (Apr 25, 2015)

i've added slivers to fill large gaps which are easy to cut from a longer rail using straight cutters. You can solder one side of the sliver.

but you may find the video below interesting to see how long a gap it takes to derail a train.


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## jlc41 (Feb 16, 2016)

Very interesting video. I have a few places on my layout where the gaps are a little wider them the rest of the trackage. Believe it or not, I like the clickity clack the wheels make going over the gaps it sound just like a real train.


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## Overkast (Jan 16, 2015)

I enjoyed that video gregc! Pretty awesome.


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## Mark VerMurlen (Aug 15, 2015)

Great video. I would have guessed derailment at much smaller gaps. Thanks for sharing that.

Mark


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## CTValleyRR (Jul 26, 2014)

Mark VerMurlen said:


> Great video. I would have guessed derailment at much smaller gaps. Thanks for sharing that.
> 
> Mark


It's the tangent track that makes all the difference.

On a curve, even that third gap probably would have done the trick (the two short breaches with the rail in the center removed)!


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## traction fan (Oct 5, 2014)

*Epoxy works*



Shdwdrgn said:


> Would it be possible to drop a bit of silicon over the rail, then when it hardens cut it with a knife to follow the profile of the rail? N-gauge probably requires a good lens to see the fine detail, but if it worked you would have a flexible gap that still holds the car wheels in place.


Overcast; and Shdwdrgn

I've used 5Min. epoxy cement to fill gaps like this. I think the silicone caulk might be squeezed out of shape if you have really serious rail expansion. In that case, the silicone might get in the way of a passing wheel & possibly cause problems. All this is speculation on something that may never happen. As long as the trains cross the gap without problems, I wouldn't worry about it. Expansion of the rails (from heat) would only narrow the gap. Contraction of the rails (from cold) would make the gap a tiny bit longer, but probably not enough to be an issue. I agree with the general idea of leaving small gaps in some of the straight track. However it takes a pretty big temperature swing to close or widen those gaps. Another trick I've used is to round off the top of both rail ends at a gap. This eliminates possible snags on blunt, abrupt rail ends. You should be able to run your fingers along any part of your track, including turnouts, without catching or cutting the fingers. Styrene, or other plastic, is also a good gap filler; I use clear plastic to fill the insulating gaps in my scratch-built turnouts. Clear plastic is harder to see. Check for the gaps near the frog, in this photo of one of my turnouts.

regards;

Traction Fan:smilie_daumenpos:


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## Shdwdrgn (Dec 23, 2014)

There is one other idea I had, but you would need some A+ soldering skills for anything at HO scale or smaller. Basically the idea is to solder a thin piece of metal to the inside of one rail, so that it would slide freely against the inside of the matching rail. Something like this...


```
#######[U]###  #[/U]#########

######################
```
By having it on the inside of the rail, the wheels could ride along the top edge of the metal strip, and the track could freely expand and contract to great extremes without affecting operations. But like I said, you would need some top-notch soldering skills to make the joints perfectly smooth.


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## CTValleyRR (Jul 26, 2014)

Wheels could ride along the top edge, yes, but you would create out of gauge track that could bind up wheels or cause derailments as the flange of the wheel rides up and over it.


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## traction fan (Oct 5, 2014)

*Strip inside the rails*



CTValleyRR said:


> Wheels could ride along the top edge, yes, but you would create out of gauge track that could bind up wheels or cause derailments as the flange of the wheel rides up and over it.


 I agree with CTV the strip inside the rails would create an out of gage problem. It could be worked around by spreading the rails slightly to compensate for the strip's thickness. Another concern would be to solder the strip to only one rail per gap. If both sides of the gap were soldered to the same strip, that strip might bow away from the inside of the rails, and into the wheel's path. Even if only one rail were soldered to the strip, track cleaning, or other activity along that rail could bend the strip out into the path of a wheel. The strip idea might be safer on the outside of the rail. 
However I think most/all the fixes we have proposed in this thread; may be a case of trying to fix something that ain't broke. Clever ideas all; but as the O.P. said, the rail gaps aren't causing his trains any problems. Why not just leave it as is?

Traction Fan:smilie_daumenpos:


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## Shdwdrgn (Dec 23, 2014)

Probably the easiest solution would be to file the head of the rail flat to the recessed side of the rail, then use a strip of metal the correct thickness to build up the difference.

@traction_fan -- yes that was the idea, the metal strip would only be soldered to one side, and allowed to slide freely against the other rail.

My planned layout is going to be in the unheated garage. It will be subject to dramatic changes in weather throughout the year. Because of this, I've been considering various ideas to allow plenty of room for expansion/contraction, not only with the rails, but also with the scenery and connections between the roadbed, scenery, and benchwork. And since my layout will have more curves than straight track, I also have to allow for gaps at *any* location along the lines.

Speaking of which, this was on Reddit this morning. It shows track buckling from heat while a train is approaching. Scary stuff!


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## traction fan (Oct 5, 2014)

*cool video!*



Shdwdrgn said:


> Probably the easiest solution would be to file the head of the rail flat to the recessed side of the rail, then use a strip of metal the correct thickness to build up the difference.
> 
> @traction_fan -- yes that was the idea, the metal strip would only be soldered to one side, and allowed to slide freely against the other rail.
> 
> ...


 shdwdrgn;

Very cool, and yes scary, video. I've never quite understood how the prototype handles expansion/contraction with welded rail. In the old days, slight gaps between rail ends, which were held between bolted joint bars, had enough play to handle it. Today many miles of continuous, welded rail would seem to be quite rigid. Something must work, as derailments are very uncommon. Maybe a member with recent prototype experience would explain it.
Wide changes in temperature and in humidity can be problems alright. Sounds like you have thought this out well. A few things I've had success with, that you may want to use.
1 Paint as much of the wood as you can, to help seal out moisture.
2 Brace the sub-roadbed to make it rigid. It doesn't need to be thick, or heavy, just rigid. I make all the track supporting sub-roadbed in the form of an inverted channel. This forms a continuous "deck girder bridge", of sub-roadbed. It can't bend or warp without cracking. Make it strong and it should stay very flat, and retain its curved, or straight shape indefinitely. Of course I paint it just like all the other wood parts of my layout.
3 Leave as many rail joiners un-soldered as possible. As we have already said. Since you have a lot of curved track, you might want to taper the rail ends in width, so that they can be overlapped within a rail joiner. If the angle of taper is small, resulting in sharp pointed rail ends, wheels should track well across the joints in any temperature. If you need to have such an un-soldered joint in the middle of a curve, track nails, or spikes can be used to hold the rails in gauge, while allowing them to expand/contract.
4 I also solder a feed wire to every single rail on the layout. They drop down and connect to buss wires in the normal fashion. The advantage of what may seem like "drop wire overkill' is that I never have to rely on any rail joint to carry electricity. Power feed is constant and reliable and no amount of expansion, contraction, oxidation, dirt, whatever, in rail joints can ever cut power to the rails. 

Regards;

Traction Fan


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## CTValleyRR (Jul 26, 2014)

I recall reading that rail is heated before welding, so that it is "pre-expanded" when installed, and the contractions due to cold temps don't cause many problems.


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