I'm almost at the stage of laying track permanently and wondered about soldering the rails together for better conductivity. I'm going to be using as much flex track as I can, for minimal joints, but wondered if there were any negatives to soldering all the joints. Any info is appreciated.
Skip
It isn't a sure thing, as in absolute, but the probability of having track buckle is very high if your tracks are welded into a single continuous length, whether closed or not, if they are also fastened securely to the bench. This is especially true if using wood products for sub roadbed and for the bench due to changes in dimensions with variations in humidity. The rail won't expand or contract a great deal, although it could with wide temperature swings. The real problem, though, is with the rails secured to the wooden components that are themselves wanting to change length under the tracks. Most buckling comes with shrinking wood as it dries. The rails don't want to shrink as much, so stresses build.
The conventional widsom is to leave a small gap of about 1 mm every two meters or so. Say about 1/16" every 6-8 feet is a good guideline, but....you can't fool them rails. They'll judge what you have done, or failed to do, without malice.
Do solder track sections to be flexed into curves so that the rails bend consistently at the correct radius at the joins. It is also good practise to stagger the joins along a curve, displacing one by about 2" or so.
Skip,
I can tell you from personal experience that Selector is right on when he says track will likely buckle if long sections are soldered together. What I can't tell you is the best way to correct the problem on large, long curves.
Selector, I have two over/under curves (HO scale) that are essentially one level helixes. I soldered the rails to get consistent curves in the flex track. I assume I need to cut two or three gaps (31" radius results in about 16' linear track) but how can I keep the curve smooth? Won't the track on either side of the gap want to straighten out? And should the gaps in each rail be cut across from each other or staggered?
Roger Johnson
I learned the hard way a long time ago - NEVER solder the rails to the rail joiners. It is imperative that a small gap be left to accommodate expansion. I am planning a two track 8 x 19 foot test oval in my garage. I will put a terminal block centered under every 3 rail sections. Track power will connect to the terminal block and then wires will run to each of the 3 rail sections from there. There will be insulating rail joiners at the extreme ends which will provide 5 9 foot blocks for signalling and cab control purposes.
skagitrailbird Skip, I can tell you from personal experience that Selector is right on when he says track will likely buckle if long sections are soldered together. What I can't tell you is the best way to correct the problem on large, long curves. Selector, I have two over/under curves (HO scale) that are essentially one level helixes. I soldered the rails to get consistent curves in the flex track. I assume I need to cut two or three gaps (31" radius results in about 16' linear track) but how can I keep the curve smooth? Won't the track on either side of the gap want to straighten out? And should the gaps in each rail be cut across from each other or staggered? Roger Johnson
Not Selector, but I'll take a shot at this.
The best way to keep rail joints from straightening the rail and causing kinks on curves is to pre-curve the rail/flex track BEFORE it's anchored to the roadbed. I don't solder rail joints - ever - but I do stagger the joints to keep one rail solid past each joiner in the opposite rail. I also massage the flex so it will lay on the roadbed properly curved before I apply the caulk that will anchor it.
When working with a single length of flex track it's easy to pre-curve, whereas pre-curving multiple lengths with the outer rail joints (in the fixed rail of the flex, if only one rail slides) soldered together could get to be an adventure!
While you're fussing with rail joints, take a second to knock the sharp corner off the top inside of each rail. That way, minor misalignment won't give a flange an excuse to climb over the rail.
Chuck (Modeling Central Japan in September, 1964)
Thanks for pinch hitting, Chuck.
Ideally you should not have to cut gaps on a curve, but for a helix you may have to...it depends. If you find that you must because the tracks want to separate from the roadbed, breaking any glue or caulk bonds as they do it, then I guess you'll need a gap or two. If I were doing it, I would try to pre-stress the sections of flex before soldering them and placing them on the curves. I believe this is what Chuck was alluding to...although flex flexes, it can be curved as well. It takes some doing and maybe ruining a piece or two, but you can bend them enough so that they want to retain some curvature. This is what you may have to do if you have to gap and want to ensure the rail end don't splay, or pop, outward as soon as they are cut.
Alternatively, since it will probably be hidden and won't need to be pretty, drive four track nails tight to the foot of the rails, on the outside of the curve. Then, on the insides of both rails, about 3/4" - 1" back along the curve, drive two more tight against the foot of each rail. These last two will be fulcrum points to keep the rails from wanting to straighten by coming inward at that point while the newly made ends flex outward. I hope that makes sense. Between the middle two nails of the four placed on the outer side of the rails where they are to be cut, cut the rails with your cut-off disk and Dremel tool. You have your gaps, but you also have two outer retaining nails keeping the ends in place, and the ones further back will act as a bend point, or fulcrum. This should keep your curve consistent.
Nobody said this hobby was easy.
-Crandell
Hi!
I just dismantled a 14 year old 11x15 two level HO layout, which was located in a spare room - climate controlled. The trackage was all Atlas code 100, using flextrack and Atlas components. All sections were soldered, with the exception of block breaks which used plastic connectors and many turnout connections. Track was secured to cork over plywood via track nails.
In those 14 years, I never had any problem with warpage or alignment whatsoever. Of course being in a climate controlled room certainly helped and my obsession for getting the track totally secured didn't hurt either.
Ok, I accept that my situation is definitely not the same as others whose layout is in the basement (or attic or garage) and realize that cutting gaps in the track every 6 feet or so is probably a must do. However, I recommend that joints be soldered wherever possible - especially at curves. This certainly secures the track sections "as best can be done", and provides better electrical connections.
On the downside, taking track apart involves "desoldering" if you want to preserve the end of the section, or using track nippers for the sake of time. When I changed siding configurations, I almost always desoldered. But when I demo'd the layout, I used the ol Xuron track nippers which typically reduced 36 inch sections by 1-2 inches. On turnouts of course, I desoldered.
FWIW
ENJOY,
Mobilman44
ENJOY !
Living in southeast Texas, formerly modeling the "postwar" Santa Fe and Illinois Central
Springfield PA
It seems there is no pat answer here. I have heard many stories on both sides in my 40 years in this hobby. Every layout I have built has had most, but not all, rail joints soldered, never had a problem. My layouts have been in basements, retail store windows and detached garage attics only heated when I'm there. One club I used to belong to, well published in MR, is in a 100 year old train station, no or minimal heat when unattended. They too have most joints soldered. That group, and the layout my father built for me at age 10 with True Scale Ready Track, is where I learned the habit of soldering most rail joints.
I live in the Mid Atlantic, 30 degress in the winter, 85 and humid in the summer. Maybe it gets down to benchwork construction (I use lots of plywood and poplar 1x, rather than pine, much more stable) or maybe just luck. While I have seen a few others have minor problems, the biggest problem I ever had was a closed up gap or two.
Even at that, I do plan for expansion, leaving joints is plastic rail joiners comfortably loose and not going more than 9-12 feet without an expansion joint. I try to solder all joints on curves, precurve the rail as Chuck suggested, and solder areas of short trackage like yard leads into one "unit".
While not necessarily true of others I know who have not had problems with soldered rail, I can say that personally a great deal of my bench work has been of a "table top" nature, then covered with whatever scenery method was desired. While it uses more lumber, I have generally prefered this to open grid and it well may be the reason I have not had expansion, contraction problems. Sheets of 3/4 birch furniture ply are my "deck" of choice and are very stable.
While I have built layouts with hand laid track in the past, my current layout is all Atlas flex glued to Homabed with adheasve caulk. I do not glue the turnouts at all, leting them float except for a track nail or two.
Sheldon
I only solder the rail joints on curves, soldering two pieces of flex together before forming the curve. This is just to prevent kinking at the joiner. On wide radius curves it's not really an issue, but if you are bending flex to 18" radius curves it can be very helpful. I do not solder any other track joints, DEFINITELY not any turnouts - if you solder the joints on a turnout it's going to be tough to repalce it should anything go wrong. I would definitely NEVER sould every joint. Kepe in mind it's not really the rails expanding - unless you build the layout in an unheated area in the middle of winter and then it gets to the upper 90's in the summer. The biggest culprit in model rail kinking is the wood benchwork expanding or contracting with humidity changes.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
From my experience you will most likely get some rail buckling if you plan on a large layout with flex track and solder all the rail joints. The cure for my particular layout was to solder two sections of flex track together leaving a small gap at the joint where the next six foot section joins up. I was fighting track buckles, "sunkinks" as the real railroads call them, because I was soldering all my flex track together and it was just too tight- there was no room for the rail to expand except sideways. After pre-curving the six foot sections of flex track and caulking it down I then solder feeder wires from the track bus to each six foot flex track sections. This provides excellent electrical continuity- especially important if you're going to use a DCC system. I have been using black Dyna Flex 230 caulk to adhere the track to the roadbed with good results. I also have been using PECO Streamline 83 track for the Main Track and Microengineering code 70 for side tracks. The PECO code 83 flex track is just a dream to work with- in my opinion. The PECO rail joiners are also longer than most and help keep rail properly aligned on curves.
Raised on the Erie Lackawanna Mainline- Supt. of the Black River Transfer & Terminal R.R.
pitshopI'm almost at the stage of laying track permanently and wondered about soldering the rails together for better conductivity.
Don't depend on rail joints, even soldered ones, to get good conductivity over your whole layout. You should plan a solid, heavy-gauge track power bus with feeders every few feet. We've been discussing the mechanical aspects of rail soldering here, but your original question actually mentioned the electrical qualities of soldered vs. unsoldered joints.
Over time, soldered connections will hold up better than purely mechanical ones. However, the issues with expansion and removeability of turnouts would argue for leaving some joints unsoldered, and these will eventually degrade as far as connectivity goes. So, your best course of action is feeders, feeders, feeders.
It takes an iron man to play with a toy iron horse.
MisterBeasley Don't depend on rail joints, even soldered ones, to get good conductivity over your whole layout. You should plan a solid, heavy-gauge track power bus with feeders every few feet. We've been discussing the mechanical aspects of rail soldering here, but your original question actually mentioned the electrical qualities of soldered vs. unsoldered joints. Over time, soldered connections will hold up better than purely mechanical ones. However, the issues with expansion and removeability of turnouts would argue for leaving some joints unsoldered, and these will eventually degrade as far as connectivity goes. So, your best course of action is feeders, feeders, feeders.
Several comments including those above have me wanting to clarify some things in my post.
I agree about the service-ablity of turnouts and do not solder them to the main run or glue them down. But I do solder them together into groups in places like yard ladders where there are often lots short pieces of rail/track in between or ajacent to them.
I use lots of feeders too, soldering is not a replacement for feeders. As a one using DC and having a signal system, my layout is blocked/sectioned into small enough sections that when combined with a high precentage of soldered rail joints seldom requires more than one feeder per section.
MisterBeasleya solid, heavy-gauge track power bus
Mr. Beasley, you raise a good point that I already planned on doing, but didn't mention in my original post. I plan on adding feeder wires by drilling next to the track and soldering them to the rails. Exactly what is a "heavy gauge track power bus"? Is there a "modeler's choice" or does everybody just head down to the Radio Shack and buy whatever's there? How do I determine what size of bus I'll need? I am building the Atlas Rancocas Harbor Belt layout (http://www.atlasrr.com/Code100web/pages/10034.htm) so how many do you think I'll need?
A lot of folk use #14 AWG solid house wire, aka Romex. Electrically it's overkill, but it's mechanically rugged and widely available. I would not go any heavier, 'cause #14 is the heaviest wire that can be easily bent to shape with long nose pliers. #12 AWG (also widely used as house wire) is very very stiff.
Actually, #16 AWG (ordinary lamp cord) is enough wire for good performance. On a small layout (say 4*8) even #18 AWG (thin stereo speaker wire) will do.
Lots of folks use surplus or what ever is lying around the basement. If you have to buy wire, take a look at All Electronics, their prices are pretty good.
David Starr www.newsnorthwoods.blogspot.com
I posted a few weeks ago about track warping due to soldering most of my joints.
I advise against soldering all the track.
I had a 14X16 layout in a climate controlled room with the track glued down very good. We got a cold spell in January and the wood shrunk then the track warped and popped loose from the glue in more than a dozen places.
Soldering a couple of sections then using a gap is better than soldering all the track.
My next layout I plan on not soldering any trackage unless I have to. The more gaps the less likely you will have warpage. Just remember to leave a minimal gap between the rails to allow for expansion and contraction during climate changes. The only dis advantage is the need for more feeders to the bus.
Bill
I am building a 21' by 13.5 foot N scale with a double main line and in a dogbone sort of layout. I used 3/4" plywood for all the benchwork, 1/2" ply for the subroadbed with cork roadbed glued to that and the flextrack adhesive caulked to the roadbed with the exception of the turnouts. I have soldered all joints except for those on the turnouts where I used plastic rail joiners. I agree with mobilman and a few of the others that your benchwork will determine a lot of expansion problems and with plywood you will have none. The other variable here is the weather conditions of your room. Mine is climate controlled and never varies more than a couple of degrees so metal expansion and contraction is practically non-existant. I have never had a derailment, bent track, or conductivity problems and have been running for almost a year through all four seasons here in Southern Idaho. I plan to go to digital and when I do will cut gaps in the rails at stretegic locations in order to set up control blocks for power in case I need to find a short or other problem. In conclusion, I think benchwork and climate control are the biggest factors in keeping soldered rail joints aligned and trouble free.
To solder or not solder the joints is completely up to the individual preference. If you don't solder the joints, you will need to feed power to each piece of rail to make sure you have good power all around the layout. If you do solder the joints, fewer feeder wires will be required. I have a fairly large layout with about 600' of track. Every joint, including turnouts, is soldered together as the track is laid. After I am satisfied with the trackage, I use a dremal and cut off wheel to cut each rail, staggered, about every 8 feet or so. At this cut I solder a loop of wire around the joint to the rail sides. I use about 26 gauge solid copper wire for this. With this method there is a continous electrical connection throughout the layout, (excluding the joint between the boosters and command station.) The loop of wire will allow any movement to take place without distorting the rails. This is not my idea as I aquired it from an old Model Railroader Tips and Tricks magazine.
To solder or to not solder rail joints:
Humidity and temperature changes in our train rooms will cause movement and flexing of our benchwork, track, and rail joints.
For the mechanical joints in our rails, rail joiners should be acceptable. Do add filler ties under the rail joiner to give support when you are pressing on the track with a Bright Boy or other mechanical cleaning approach. [For my roadbed, I am using cork on foam rubber camper tape on plywood (a great combination for sound deadening characteristics), so my roadbed is fairly soft. In this situation, a solid solder joint is my preferred approach. Occasional traditional joints ARE needed to allow for the expansion and movement of the rail.]
For electrical continuity, feeders for every section of rail is the ultimate. Relying on the rail joiner is not a good long term approach. You could always start with just rail joiners, and add feeders only when you start having electrical dead spots. Hmmmm. Good luck!
Just to add a little fun in the discussion, I would like to address the comments regarding the relative effects of temperature and humidity on our track and roadbed systems.
Thermal expansion:
All materials expand with a rising temperature, and do so at different rates. Although I do not have data on our “nickel silver” rail, most metals and their alloys have a coefficient of thermal expansion around 0.00001 inches per inch per degree Fahrenheit. (A piece of rail one inch long will get longer by 0.00001 inch when its temperature goes up one degree Fahrenheit.)
Our benchwork also expands with temperature. I do not have a good number for regular pine or fir wood, but plywood has a coefficient of thermal expansion of approximately 0.0000034 inches per inch per degree Fahrenheit.
So both will expand together with a temperature rise, but the net difference is 0.0000066 inches per inch per degree Fahrenheit.
So, lets look at a 36 inch piece of rail on a plywood base that sees a 20 degree temperature rise (say from 60 degrees to 80 degrees). Working the math: 0.0000066 x 36 x 20 = 0.004752 inches. That is a relative movement of about one third of a 64th of an inch for a piece of 36” long rail sitting on a plywood base. Not really very much.
Humidity – Hygroscopic effects:
Metal is not affected by humidity, but our wood/plywood is very sensitive to relative humidity. Fortunately, the length is the more stable dimension – you don’t want to even think about the swelling across the grain. Plywood is relatively stable across its face, but, again, thickness is subject to wide swings. The APA –The Engineered Wood Association, says that plywood (whatever variations that my include) will expand along its eight foot length by 0.09 inches when the relative humidity swings from 40% to 80%. For a 36” length that works out to be 0.03375”, or approximately 1/32th of an inch over the length of one piece of flextrack. That may not sound like a lot, but over a 12 foot section of soldered rail, that adds up to 1/8th of an inch. Now that’s a big gap for N or HO.
So, humidity can cause seven times the expansion problems of temperature.
So, what to do?
Control humidity! Keep that humidifier running all year!
Solid benchwork. Plywood benchwork and framework is likely to be more stable than 1x4 or 2x4 lumber. Beyond these usual solutions…..
Folks have built benchwork using steel studs, but the subroadbed is still usually plywood. Hmmmm. And for the folks using a Homasote spline roadbed, well, that expands three times more than plywood with humidity changes.
I have limited knowledge of foam products for a roadbed or working surface. It should be less sensitive to humidity changes, but foam has a whole new set of challenges.
Anyone have other suggestions and experience on other construction methods?
Real railroads anchor the rails to ties to prevent buckling and the temperature differences result in stress in the rail, not movement.
I soldered all the joints and had buckling track when the Homasote dried out, (after a year of climate control), but it seems to me the 3/4" plywood helped. Also -- painting the rail helped, because - like the real thing - it helps 'anchor' the rails at each tie.
If I get another buckle, I'll cut a gap with the Dremel and re-solder the joint. Next time, I'll plan a bit better and leave some gaps between feeders.
Older modelers, like me, may remeber Linn Wescott recommending letting your lumber (and Homasote) 'season' for a year before starting construction (or maybe, track laying).
The lumber for my layout was stored on pallets outdoors at my "lumbre-mart". I knew to take it down to the basement, lay it out in such a way that the air could get to it, and then waited for a week. My basement is de-humidified to about 40-60% year round. Fortunately, none of the boards twisted or split. Now, three years later, the bench is as solide as ever. The tracks are on six-ply 1/4" MDF spline roadbed. They haven't given me a lick of trouble. Mind you, I only soldered along the curves.