This subject has been addressed many times. In the February, 2011 issue on page 48, building the Bay Junction, David Popp talks about soldering the rail joints in the switching yard. What is the best way to go? In a yard design and on straight tracks should you not solder and leave a small gap between all the joints, to compensate for expansion. Or should you solder all joints tight together, regardless if they are located in your curves or on straight sections.
If it is best to design gaps in all the joints on straight track, I have two more questions:
Is it smart to do this to joints connecting to turn outs?
Does anyone know the recommended practice on the size gap to leave between the joints in the straight sections?
I have already decided to solder all the rail joints in all my curved sections. Any opinions will help.
Do not solder all joints to allow for expansion and contraction except for curves. A failure to solder the joints on curves may lead to kinks in the track. I have never heard of anyone leaving small gaps to allow for expansion or contraction and it doesn’t seem to be a good idea. If you do it when the track is warm and the tracks get cold it would cause an even larger gap. It’s important to electrictically bridge the sections not soldered or drop feeder wires from soldered sections to bus wires.
After 7 years and 3 different layouts, I have tried every technique from totally unsoldered rail joints, to soldered curved flextrack, to soldered straight sections.
Here is what I do now with total success. Solder all flextrack on all curves, solder feeder wires to the bottom of rail joiners every 6 to 9 feet, do not solder any turnouts, do not intentionally create gaps between rails.
On my next layout, I will solder the underside of the rail on every piece of flextrack, solder the underside of the rail on every turnout, solder the rail joiners on all curves in flextrack, and do not intentionally gap any rails.
If you solder the joints, no matter what kind of gap you leave, the track won’t expand; you’ve made it a solid joint. The common misconception is that the rails contract and expand with temperature changes. It’s actually the wood that’s expanding and contracting. If you want to allow for expansion, don’t solder the joints. Solder feeders to each section and tie them into a common buss wire, using the rail joiners only to maintain rail alignment.
If your layout is in a NASA clean room, where the temperature and humidity never vary by as much as 1%, by all means, solder every rail joint.
OTOH, if you live in the real world of temperature extremes and wild swings in humidity, you might find that that perfect tangent has turned itself into sidewinder tracks or a roller coaster when the conditions swing to the far end of the climactic spectrum.
Somebody said they had never heard of anyone who deliberately left gaps for rail expansion. Say WHAT? Just enter “rail joints” in “Posts by tomikawaTT.” I must have posted at least 50 times that I don’t solder my rail joints because my rail DOES creep - and the reason is the 100 degree annual temperature change in my layout space, not humidity. (Humidity? Here in the Dessicated Desert, WHAT humidity?)
So, for at least the 51st time - I do NOT solder rail joints. I DO solder jumper wires around every uninsulated rail joint to assure bulletproof electrical continuity. I pre-bend rail which will be laid on curves, including flex track. I stagger my rail joints, especially on curves. And, yes, I leave gaps for expansion unless I’m laying rail in mid-afternoon in August. The only rail-to-rail soldering on my layout is found at the frogs and guard rails of the hand-laid specialwork that intrudes on my runs of (mostly Atlas) flex track. A derailment is such an unusual event that it always prompts a thorough investigation - and is almost always traced to a rolling stock failure.
Chuck (Modeling Central Japan in September, 1964 - with expansion gaps at his un-soldered rail joints)
I learned the hard way about leaving gaps. I was ready to run some trains and noticed a hump in the track in the rear. About 2 feet of track had to be replaced. My rule of thumb is if you build the layout in the middle of the summer, leave gaps, since the layout is already expanded. If built in the middle of winter don’t leave gaps because the summer will bring heat and humidity and expand.
From what I found the effect is opposite of what many think. When the wood expands the gaps will form since it’s nailed to it. When it contracts the gaps disappear since the wood pulls the track together. If using foam it doesn’t matter as much because the foam won’t expand.
I also use feeders at every section of flex and don’t solder rails, unless on a curve that isn’t behaving.
So what can we say that hasn’t already been covered?
There is no best way. You will find people who swear by both extremes. The only thing I solder is flex track on curves. That is the “best” way for me and my situation. But different things work for different people because layouts are day and night different. I am in a very arid environment and don’t have humidity expansion and contraction problems with the wood bench work. It depends on more than the track. What is the bench work made of, what is the sub-roadbed, and roadbed made with. Is it a flat sheet, cookie cutter, or open frame construction. Does the humidity and/or temperature vary greatly in your area, is the room climate controlled? The more climate controlled the less it matters.
Ditto it depends if the track is in a climate controlled environment, or does the temperature vary greatly? Then are you laying the track in the heat or the cold? If it is hot the rails should be crammed tightly together, the colder the bigger the gap. How long is the run of track because the longer a solid piece the bigger the gap needs to be? Seems like someone here calculated the expansion for a 90’ piece of nickel silver was 1/4" for a temperature range of 40 degrees. So one has that much temperature variation, if using standard flex track with zero soldered join
As has already been mentioned, no one method suits all situations. [swg]
I solder all rail joints, including turnouts. Any gaps which I cut are for electrical purposes only, and those gaps are filled with grey ABS plastic, ca’d in place. The layout is in an unheated (but well insulated) basement, with a dehumidifier running nearby (not in the layout room) during the summer months. There is approximately 200’ of mainline in-service, plus a similar amount of passing sidings, double track, and industrial spurs. Train power is DC, supplied via a single pair of wires running from the power source to the nearby track, with tethered walkaround control. If there’s expansion or contraction, it’s not apparent either visually or operationally.
I have soldered all rail joints including turnouts as well. I agonized over this decision initially but wanted as solid (literally) electrical dependability as possilble as I plan on operating sessions with some serious operators and wanted to limit glitches.
I live in the Pacific NW and have used Lowes and Home Depot lumber, but having come from a boat repair background, air dried my lumber in the train room for several months (some, now 2.5 yrs.) and have expereienced humidity shifts from 455 to 80% with no issues.
My good friend here on the forum did have some expansion buckling, but simply took a dremel tool and recut the rail in a few places and it was fixed very quickly. (although he has no ballast yet) and he convinced me to solder everything if I was going to do operations and see how it goes.
So here’s hoping, but after two summers, two and a half winters, things have been ok.
If you don’t plan on operations sessions on a regular basis with very experienced operators who’ll give you no end of good natured crap over glitches, soldering may not be as appealing to the OP.
I thought I might invest in a dehumidifier but haven’t felt the need yet. My layout IS upstairs, but our house does not have central heating and the layout room is relatively cool.
Most everybody has done a good job of answering. I didn’t see this, so let me add:
For curves in particular, offset where the rails join by about 2" or so. This means one piece of flextrack will have it’s rail inside the ties of another piece of flextrack.
Solder just enough to hold, not too much to make the joint inflexible. Solder the joint with the track curved only some so that when you bend the track to the curve you want the rails will be nice and smooth as they bend.
I also soldered everything including turnouts, I had a couple places that buckled the first year, I also just recut them until they laid flat again and secured the gaps by soldering a short piece of wire across the gaps. I have drops every 10 feet or so. I did not stagger rail joints anywhere. All rail joints are solidly soldered. The track is glued to cork and foam roadbed which is glued to pink and blue styrofoam which in turn is glued to 5/8" plywood of a 1x4 grid structure . I ballasted the track in the second year (before scenery) and have not had a problem in the 18 years the track has been in use.
Assuming I glue and screw my (wooden) benchwork together solidly and don’t leave gaps in my benchwork sections, if they expand, won’t my benchwork buckle too? [*-)]
Your bench work will indeed expand and contract but if the various pieces are attached to each other properly then there will be enough strength to resist buckling. The shear forces working against the joints will not be strong enough to break the joints. In severe cases you might get a crack in straight pieces of lower quality lumber but for the most part the wood will absorb the force.
The problem with track buckling is that the track is not strong enough to prevent the benchwork from moving, nor is the glue between the track and roadbed/subroadbed strong enough to overcome the movement of the benchwork. Also, as others have said, the track expands and contracts much less then the benchwork. The result is that there is a lot of shear force happening right at the track-to-benchwork joint with no way for it to be distributed except by popping the track loose.
I’m afraid I’m not following your response totally. If there is no gap in the benchwork, if the sections fit snuggly to begin with, it seems like there would be no place for the benchwork to move, thereby no movement of the roadbed and track above.
I can see where if there is even a 16th inch gap between benchwork sections, that 1/16th gap could create havoc with the track as the wood expands.
I’m thinking that the variety of responses and experiences above maybe indicate that the relative precision/imprecision with which we build are benchwork has as much to do with track buckling as does environmental conditions or soldering joints has.
You’re probably right in many cases. I’ve seen what appear to be very well-done layouts, but the benchwork is junk material put together carelessly: almost like the builder was anxious to get to the stuff at which he was really competent, and sloughed off on building a proper foundation for the visible goodies. Needless to say, operation was less than impressive.
Construction grade lumber (2"x4", etc. and strapping grade 1"x2" etc.) is not that far removed from the tree, even when kiln dried. You’d best wear safety glasses when driving nails into it, as there’s a good chance you’ll get squirted in the eye. [(-D] Even once assembled, it will continue to dry and, consequently, change shape (warp, bow, cup, etc.) Better perhaps to spend a little more time on the construction of the benchwork and be, perhaps, a little more particular about ones choice of materials.
I have to reiterate that many of us simply don’t have access to the choicest lumber or can always afford it. (Yes, false economy and all of that, taken into consideration) but if you don’t, DRYING adequately with proper stacking techniques and the PATIENCE to store that lumber in your future train room for as long as feasibly possible (months, preferred) will serve you very well. Even a couple-3 weeks is probably ok.
Can I say that my Lowes and Home Depot lumber will NEVER warp? NO…but after 2.5 years as benchwork it’s likely that it won’t. Other cheap lumber compromises can be made as well.
I never even entertained the thought of 2X2s for legs as they were all severly warped at the store. I have no power wood shop tools so I couldn’t rip 2X4s down to 2X2s anyway.
2X4s were dependable and if they weren’t there were only 2 out of many that warped in the drying stage, rather severely. Out of a “zillion” 1X4s only a couple of those bowed at all because of the proper stacking/drying. So…cheap lumber CAN be utilized IF proper precautions are taken beforehand to thoroughly dry and monitor them. If they’re going to warp let 'em do it well before they’re built into your bench work.
I was able to have the patience because I was still finalizing track plans while my already purchased lumber was drying and had nothing to start building yet anyway.
If you’ve got your plan and are chomping at the bit, this will be much harder to refrain oneself. Buy any lumber, top quality or not as early as you possibly can and air dry, dry dry it out. Even lumber yard (stored outdoors in rainy Washington State) that has been kiln dried can warp if not acclimated to your room for enough time.
My lst layout used relatively expensive lumber yard lumber and still warped because it was in a damp basement and hadn’t been re-dried by me.
After pricing better quality wood with my box store wood, I d
All good points, Capt. G. I suspect many not only don’t know about acclimatising/drying the wood before use, but may not have the patience to do so, either. In some cases, that same lack of patience is what compels them to buy cheaper lumber instead of waiting a couple of months while they save up enough spare cash to buy the higher quality stuff.
We’re all in a rush to get to the “good parts” of model railroading (and which those are is up to the individual) and lose sight of the fact that this is not a race. Time spent on the preliminaries (and this includes room preparation) is well-spent, and pays big dividends in enjoyment later.
As you point out, there’s nothing wrong with the cheaper stuff when it’s handled properly. While the big home improvement stores have their lumber indoors, it rarely sits long enough to dry beyond what it did at the mill. The smaller yard where I usually deal keeps their framing lumber outdoors, with the higher quality stuff indoors in an unheated building. Either way, I pick through to get what I want. When I was buying by the truckload when building my house, I was told that anything which I found to be unsuitable would be replaced.
Even lumber stored outdoors can be stacked to aid (and maintain) drying and prevent distortion as it dries, although most yards no longer bother, as it’s labour-intensive. Nowadays it arrives banded (stays nice and straight, at least as long as the banding’s in place) [:-^] and is usually left so until the previous bundle is almost used-up.
actualy going with a narrow shelf layout with narrow hollow core doors about 16"- 18’ deep the appropiate size shelf brackets from walmart or cheap place,saves a lot of hassle with board warpage i have started a L shape layout using hollow corp doors that are 16 inch deep. these doors had been in our attic for 2 summers with the heat rose to 110 plus and minus 10 degree in the winter with who knows what for humidity, and no warpage.about soldering the rail joints i normaly go every 6 feet with a non soldered joint and a slight expansion gap, and a jumper wire. i started doing this after a wierd thing happened at another place years ago, i was eating dinner and the was a loud THUMP sound coming from the trainroom i go in there and all the rails popped off the ties, this was using atlas code 100 flex everything soldered, the room temp must have been between 80-100, so that realy messed up progress, luckily the engines were just knock on their sides.