I’ve always been told that you have to leave a gap between pieces of track to allow for expansion. I don’t have to worry about that here in Arizona because we seem to have a permanent over 100 heat wave going on.
On the other hand the best advice on YouTube University is that you solder all the joiners and stagger the joints to keep the track from buckling.
I figure that you guys will know all the pros and especially the cons of both methodologies.
It might not get as hot here in Bako (Bakersfield) but the higher triple digits are pretty common. I eroded when we moved to Bako. I built my layout in our garage and soldered all the joints on my Atlas code 83 Flex and it took a couple of summers and heat really dinged my track. I had used ballasted white glue on all of my viewable track and just track nails on my hidden track. One day I ran a passenger train around my layout and it didn’t come out of my mountains. The well glued track did well but three sections of un glued flex track had exploded. The rails broke loose from the ties in three sections of flex track. Of course it was all hidden track and the most difficult to replace.
I now leave expansion joints in my track.
Mel
My Model Railroad
http://melvineperry.blogspot.com/
Bakersfield, California
I’m beginning to realize that aging is not for wimps.
Chip, one-hundred feet of contiguous Code 100 N/S rail will expand or contract longitudinally only 6mm (0.25") with a change of 30 D Fahrenheit. Three or four non-soldered joiners along that 100’ will handle any thermal expansion or contraction if the gaps start at about 1/16".
What most of us find is that, since almost all of us use milled lumber for our baseboard/layout, and since wood changes in dimensions across the grain when humidity rises and falls by about 30% either way from initial state (45%-55%), the rails are going to buckle, sproing, or retract and break solders when humidity changes substantially. The ties, if solidly affixed to the wood, will attempt to ride along with the expansion on axis, while the rails want to do their own thing. Eventually, those teensy spikehead details throw in the towel.
As a result, I solder most of my joiners, maybe 80%, especially along curves, and I run a dehumidifier all year set to shut off at 48% and to start drying at 65%
My layout is in a first floor bedroom in our house. The temperature doesn’t vary more than five degrees year 'round.
I first started by soldering my flex track curves because I had issues of the track curving incorrecty at the joints. Later, I soldered every joint. My layout is only two years old, but, knock on wood, there haven’t been any problems yet.
I’ll add some more info on my garage. I had never checked the temperature in our garage (2 years in the new house) and after the problem I found out the temperature swing between winter and summer was 35° to 106°+ or 70°+.
After the tragedy I had an additional R30 added to the attic. The swing now is under 34°, I still leave adequate gaps in my track!!! I never want to go through that again.
Mel
My Model Railroad
http://melvineperry.blogspot.com/
Bakersfield, California
I’m beginning to realize that aging is not for wimps.
Last two layouts, I soldered two pieces of flex together and used that for curves - so even though there is a joint in the middle of the curve, which is unavoidable in a 90 degree or more curve unless it’s a really tight radius, the rails and joiners were all soldered prior to forming the curve. The joints ens up not being parallel to one another, although since they are soldered I don’t think it matters much, they won;t kink like unsoldered joints.
I also used two pieces of flex soldered together whereever I could for straignts. The joints between two pieces of my extra long 6 foot sections was left unsoldered. Each soldered pair had feeders, so the unsoldered joint was just a seconday electrical path, not a primary one.
It worked for two previous layouts, I see little reason to change. I am using wood (plywood, mostly) for the benchwork and subroadbed this time, so there is ptential for move movement in the supportign structure. Last two layouts were foam. But since essentially every other joint is not soldered, there should be plenty of room for things to move. My basement is fairly well sealed now, with vapor barrier and insulation on all exterior walls, and a full drop ceiling. There’s heat, but no ac. I do have a dehumidifier which seems to be able to maintain 45 percent on the hottest and most humiod days. It was alte winter when the work was finished, but it stayed warm even though I still have to hook the thermostat back up (I’m thinking I will not need to actually use the heat any more - which should save some on the heating bill - the insulation combined with the furnace and water heater running seem to make enough heat). It wasn’t horribly dry, but we had a fairly wet winter (rain, almost no snow). Have to see how dry it gets this year. That will probably be my biggest issue - getting too dry now, since witht he foundation sealed and insulated, the moisture that was getting in and giving the whole basement a damp smell is no more. Now it just smells l
I have been soldering all my rail joints for 50 years, only leaving gaps/plastic joiners were needed for electrical reasons (I run DC).
Many of my blocks are/have been 50’ or longer.
Never had any problems.
Sheldon
When I soldered every joint, I had rails in one place break out of their molded spikes. So now, I leave a few unsoldered joints on tangent track. Curves still have every joint soldered.
Paul
all track sections, whether flex or sectional, are soldered … the only exception here is the turnouts are not soldered, on either end …
the layout is fifteen feet by sixteen feet, with a 2.5 per cent grade on most of it … it has been trouble free for seven years now … [oh, it’s HO, mostly Atlas code 100, with Atlas number six Custom Line turnouts]
I’ve lived and built layouts nearly all over the country - Seattle, New Jersey, South Carolina, Lompoc California, Orlando and Wyoming. The only place I ever had track issues was in New Jersey, because of benchwork movement from changing humidity (a dehumidifier fixed that).
Unless you have huge runs of tangent track, changes due to temperature will not generally be an issue. I just eyeball a business card thickness-sized gap at all rail joints on tangent track, and call it good. It’s always worked.
I solder all joints on curves, because that’s the only way I can get a smooth path around the curves. They’ve never given me a problem anywhere except as I said in New Jersey.
Since AZ is generally very dry, I wouldn’t worry about it. You’ll be fine.
Number seems a bit high but even if true, how many people have 100’ straight mainline. Ussually people have problems with expantion because the put their track down on ply, thats why I use foam. It only shrinks notably when new ( most people that buy at home stores never see stuff that is new enough to worry about.
Me too. My layouts have always been in the “normal” house area and have been rigidly kept at the same temperature year round.
No problems.
-Kevin
It’s not the rail - it’s the wood supporting structure.
It’s the rail on the prorotype, because of how long a section of continuous welded rail is, and also depending on where inthe country you are, there’s a considerable temperature swing. Here we can get to the single digits regularly in winter, and high 90’s regularly in summer. If your layout space varies that much, perhaps you should consider a different layout space - one you can keep within a human comfortable temperature range, which will result in very little metal movement.
Humidity swings though, with wood structures - maybe my slow construction progress is actually a good thing, as the wood sits in my basement for a while before it gets used - although not really long enough to truly season to the environment. It’s it’s constantly dry, or constant high humidity, it should be fine. WHen it swings, like it does here, between very dry in winter to very humid in the summer, if you don’t control humidity in the layout area, it will be a problem. If you can’t control it, alternative building materials may be for you - like steel stud benchwork. Humidty change will have little effect on that.
–Randy
My construction is a box of 1x4’s and the foam is caulked on top of it, no wood problems.
I def solder joiners for curved track and not for straight. When starting in MR, one of my biggest Qs was how to solder curved track. I learned by trying!
Clearly, adding spacing to track depends on multiple factors. Geography of the layout in a house, part of the country, how much sunlight, moon phase are just some (of many) other factors. It seems no two have the “right” answer.
I’ll throw in my two cents …
My layout is almost 25 years old. The ONLY time I had a few cases of track buckling was in the first two years and it was only three different spots. Every joint on my layout is soldered … at least I thought they were when I discovered a dead spot on the layout a couple weeks ago. Turns out I missed soldering a joiner and for whatever reason, the joint quit conducting !
My layout is in a room that is heated / cooled the same as the rest of the house. Once my (green) lumber climatized to the environment, I have never had any further issues. Remember, it’s not the track moving, it’s the benchwork.
Mark.
I solder all rail joints, then cut gaps for isolating some track sections, where required, cementing Plastruct ABS into them.
My layout is strictly DC, in a basement room, neither heated nor cooled (the temperature varies little, due to good insulation), and a dehumidifier runs, as needed, all year round. No issues at all with track.
Wayne
Quite my point. Who has that much linear feet of ‘welded’ nickel-silver in ANY code? So, thinking of saving one’s rails from the dreaded buckle by assuming it’s due to thermal expansion is misguided. It’s many times more likely to be the wood expanding or shrinking.
My HO layout, a couple years old, is a 5x9 mobile layout in 3 5x3 sections bolted together. It gets moved to shows several times a year, to a fire station, armories, poorly climate-controlled buildings, etc. as well as my basement (well not this year w/ Covid). I run a DCC buss under the rail and enough track feeders that at no point is the track more than one joint from a feeder. (With a mobile layout, you can set a section it on its side to make wiring easier and not lay on your back!) None of my joints are soldered and on other layouts I only solder if necessary, which is rare. I have not had a problem with track expansion or getting power through unsoldered joints. On large curves, usually working a slight bend with plyers and needle nose plyers on the ends of flex track can make a smooth curve without solder.
Our club HO layout started by previous members has a lot of soldered joints. I have had to redo several joints where, after many years, power did not get through usually by just heading the joint. The layout also has a lot of older Shinohara turnouts where point rails have come loose from the throw bar. The ones with unsoldered joints are much easier to repair. It is also easier to modify layouts where joints are not soldered.
Just my $.02,
Clark
I didn’t believe rail expansion was significant until I saw it for myself. Club had set up HOn3 modules (code 70 rail) inside a building in Denver for Christmas display. Everything running/working fine. Heat in the building was kept on.
Came in next day to set up for the evening. Sunlight from a window was falling on track handlaid across a beautiful trestle. All joints on the 4ft module were soldered, per our practice. One rail had sprung into a beautiful bow, taking out the spikes from the ties.
Once a gap was cut in the rail, it was re-spiked to the ties, and all lived happily ever after. If I had not been there in person, I would have never believed the story, either.
Fred W