# Expansion question



## jake3404 (Dec 3, 2010)

I am building an outdoor layout and will be using Sunset Valley Brass rail. I've read a lot about how various people have controlled expansion. And am curious if I were to not soldier or use rail clamps, but just the joiners, would I have a problem with alignment?

The background on this question is, I have an HO layout built in a separate building on my property. This building is not climate controlled unless I'm in it. So it experiences temperature variations of 110 F to -20 F. I was worried about expansion on my Nickle-Silver rail and so I did not soldier any joints but ran feeder wires to each section of track. Thus I have no conductivity problem. In the past 8 years I have had no problem with expansion and alignment. I'm assuming I can use the same concept on my outdoor layout. 

A few other pieces of info: This will be Radio/Battery power (thus Im not worried about conductivity) and I will have a floating roadbed. Any input?


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## blueregal (Jan 3, 2008)

I have the joiners, and as far as I know NO alignment problem, but knowing what I know now I wish I would have used clamps instead of the lesser expensive joiners!! And your biggest problem outdoors will be conductivity, after some months or year, or so!! And as far as expansion, I live where it can be 17below and climb to 55 degrees the next day, and do have some expansion, but not a severe problem that I know of. Regal


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## eheading (Jan 5, 2008)

Jake, I have a radio controlled, battery powered railroad outside here in Florida. We have pretty big temperature extremes here. I just use joiners for my track, and let it float and I have had no problems at all with contraction and expansion. I personally believe that the main reason I don't have problems is the floating track. Since you're planning on using battery power, and conductivity is not an issue, there is no need for the expense of clamps. The only places I use clamps are where I have cut a section of track (too lazy to drill little tapped holes in the track) and where I want access, like at some switches that I might want to lift out and clean occasionally.

Ed


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## aceinspp (Jan 2, 2008)

Jake: As long as your going to battery poer forget the rail clamps and just use the rail joiners. You will not be concerned with power feed so no need for the extra expense. You can free float the track as I do and you should not have any problems with expansion Just remember to lay track in the summer and not the winter. Later RJD


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## Ron Hill (Sep 25, 2008)

Jake, check the article on page 3 of the track, trestles, bridges forum about thermal expansion by Bob Hyman. No matter whether you use jointers or clamps, you will have expansion in summer and winter. That is the nature of metal. As Ed stated, the best way to deal with thermal expansion of rail is a floating track. 
Ron


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## armorsmith (Jun 1, 2008)

Jake, 

For battery power I agree that it really doesn't matter what method you use to join each section of track, so long as they are securely joined. Either rail clamps or standard joiners (with both screws installed) will work fine. However, if you are going to float the track and allow nature to determine where the expansion/contraction occurs, then secure joints are a must otherwise when the track contracts to its fullest extent it is entirely possible for track to separate. My club in Florida has experienced separation and we use Split-Jaws, but our track was originally secured to a ladder system. We have had no separation since we allowed more of the track to float. 

My tuppence worth. 

Bob C.


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## jake3404 (Dec 3, 2010)

Thanks for the info guys. One of my concerns was the separation at the joint when the rail contracts and if it would contract enough to slip out of the railjoiner. Like I said I have been using this method to great sucess in my HO layout, the biggest difference is the HO layout is sheltered from the weather. However, if I remember from my metalurgy classes, its not the weather, but the temp that causes expansion/contraction. So, I should expect similar results wither the track is inside or out.


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## Totalwrecker (Feb 26, 2009)

Outside you get the sun's power to overheat the rails and they do grow. Items exposed to the sun's rays get hotter than the ambient temperature of the air. Like a car becoming an oven to a passenger.... or an asphalt road too hot to walk on... 

IF you want the rails to stay confined to benchwork or bridges, trestles and so on, then you will need expansion joints in straight aways ,to prevent kinks. The rail must go somewhere. 

On my layout, a large tri-oval floats in ballast and the whole oval expands and contracts as a unit. I use Aristo Stainless steel and I torque set the darn tiny joiner screws. The rails do not pull away from each other, the expansion I see (and I do 'see' it) is 3/4" laterally on the 90 degree curved trestle. I accepted the 10' rule #62 (I'm lazy) and just laid track on it, if I didn't, the strength of the rail could push the trestle off it's footings. I like the strength the screws add to the rails... continuous I beams! Similar to bolted fishplates. 

I have 40 years of indoor trains; Lionel, HO, Z, On3 and Nn3, but outdoors is totally different, including the 10' rule; Can you see it at 10'? If not, omit it. That was a tough nut to swallow coming from Finescale On3... but G ga. is full of compromises... my mind's eye saw wide sweeping curves and prototypical grades etc... but that sure eats up real estate fast. Aristo calls a 10' Diameter switch a 'wide' radius switch.... 10'D =5'r>60" For ease of mental math use 1:24 for G, then 1:48 (US O) would be a 30"r and HO (half O'ish) 15"r. Gives a new perspective doesn't it? 

I laid my track during the fall around 70 degrees (my range; 20 -120F a mostly dry, cloudless sky heat ray) so I see expansion and contraction from the 'as laid' position. Last year I added a reverse loop connected by a wye and haven't had any alignment problems from the more complicated track plan. I use clamps where I've cut tracks or have a mis threaded hole... she grows as a unit. 

Floating is what the big boys use and it has worked well for me. Others I respect use a concrete roadbed and semi-secure their track to it. 

John


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