Soldering track joiners

[RR_Mel]

 

I feel the need to relate my experience of soldering track joiners to model railroaders new to the hobby.

 

First I will say that I started my HO scale hobby in 1951 with paper route money and I’ve learned many lessons over 64 years, usually the hard way.

 

I built several layouts in that time frame learning what works and what doesn’t work each time.  Finally after moving to Bakersfield California in 1987 I designed and built my "perfect model railroad layout".  The garage became Mel’s Train Room.  The house we bought was the model home for the tract where we bought our house.  It had all the goodies including a finished garage.  The garage was the tract sales office, carpeted with textured walls and ceiling.  The first owner had removed the air conditioning ducts and carpet so the garage was no longer temperature controlled, after all who needs to cool the garage and a carpet for their cars.

 

I proceeded to build my perfect layout.  I only worked on my layout in the garage when it was workable.  Bakersfield gets anywhere from 100° to 115° for highs from May to October and 20° to 30° for lows from December to February.  The closed up garage would get as hot as 117° during the summer months.

 

I soldered all of my Atlas Flex Track joiners and while I didn’t glue the track down I did use track nails to keep it in place.  Everything went very good for many years, then it happened!  The severe temperature changes over time did their thing to my track by way of expansion/contraction.  I experienced derails everywhere.  Expansion of the rails had broken the plastic rail spikes on the ties on most of my curved track.

 

I wanted to express the need to use expansion joints on layouts located in areas without some type of temperature control.

 

Our garage is now temperature controlled between 58° for the low and 88° for the high.  I added an additional R30 insulation to the attic and reinstalled a small HVAC outlet, enough to keep the temperature variation from 85° before to 30° now, much better than the 30° to 115° it had before.

 

To add a bit of embarrassment to this post, I’m a graduate EE and knew better but I still had to learn the hard way.  I guess I had my MRR hat on at the time.

 

Mel

 

 

Modeling the SP in HO scale since 1951

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

 

[charlie9]

My lifelong experiences have led me to believe that wide variations in humidity are much more of a problem than changes in temperature.

Be happy in your work.

Charlie

[richg1998]

charlie9

My lifelong experiences have led me to believe that wide variations in humidity are much more of a problem than changes in temperature.

Be happy in your work.

Charlie

 

I live in New England where we have cellars. The humidity can get quite high without humidity control and raise havoc with track on Homasote.

Rich

[SouthPenn]

I usually solder all my rail joints. But, none of the switches have the main or diversion tracks connected to their respective tracks. There is a gap on both rails. As my railroad is in the basement, I think these gaps have helped eliminate most track walking issues. This wasn't by design, it just worked out that way.

South Penn

[RR_Mel]

charlie9

My lifelong experiences have led me to believe that wide variations in humidity are much more of a problem than changes in temperature.

Be happy in your work.

Charlie

 

I’ve never lived around high humidity, I think someone should do a like post and inform new layout builders the do’s and don’ts of humidity problems.

 

I ended up replacing a lot of destroyed track from the constant expansion and contraction of the rails of which also involved a lot of scenery too.

 

I think any advice one can give first time builders would be a great help.  Learning the hard way is tough!

 

Mel

 

 

Modeling the SP in HO scale since 1951

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

[hornblower]

I would think that wide humidity changes mainly affect the benchwork while high temperature swings (what I experience in Fullerton, California as does Mel in Bakersfield) affects both the benchwork and the track itself (rail expansion/contraction).  Either way, the result is trackwork that gets pushed around from where we originally placed it.  I hand lay all of my turnouts and found that I had to cut wider gaps at the frogs due to rail expansion during high temperatures closing the original narrow gaps cut with a razor saw. Fortunately, using the razor saw to recut the closed up gaps during a high temperature period solves the problem on turnouts already installed on the layout.  Once I discovered this problem, I cut the gaps of all newer turnouts using a mini hack saw with a slightly thicker blade prior to installation on the layout.

Instead of soldering all of the rail joiners, I prefer to use N scale Code 80 joiners on my HO scale Code 83 track and solder power feeders to every section of track.  I also try to account for rail expansion/contraction at all rail joints.  Instead of a "standard" rail gap for all joints, I have to take into account the temperature during the time I install my track work (my layout is located inside my finished but not temperature controlled garage).  If the temperature is cool during track installation, I use larger rail gaps to allow for rail expansion in hot weather.  If it is hot during installation, I use smaller gaps so the gaps won't grow too large during cool weather when the rails contract.

 

[floridaflyer]

Don't believe the track expands or contracts very much. The benchwork on the other hand can move quite a bit as humidity changes. I painted the benchwork with oil based enamel to help reduce the effect of humidity.  

[BroadwayLion]

YUP definetly the benchwork.

 

ROAR

[rrebell]

Build your trackwork on foam and forget the ply, much more easy and no expantion and contraction problems.

[richg1998]

Homasote can absorb moisture like a sponge. I had to install a dehumidifier with condensate pump so water was pumped out regularly.

Foam would have been a better way to go.

Rich

[tomikawaTT]

My experience is very much in line with the OP's.  Rail gaps at joiners are needed for RAIL EXPANSION control.  Humidity has exactly zilch to do with it.

Why am I so sure?  My benchwork, and some of my under-roadbed subgrade, is steel.  Steel studs, unlike forest products, care less about humidity (or, in this area, lack thereof.)  They do experience thermal expansion - but only about half that of nickel silver.

So, I absolutely, positively DON'T solder rail joiners.  I solder electrical jumpers around all non-insulated joiners, and dress the rail ends to remove anything that might contribute to a derailment.  My rail joiners might slide like trombones, but my trains operate reliably.  I guess I'm doing something right.

Chuck (Modeling Central Japan in September, 1964 - in a Clark County, NV, garage)

[Texas Zepher]

floridaflyer

Don't believe the track expands or contracts very much.

It doesn't, but it is amazing the amount of damage a tiny bit of expansion can do when it has no where to expand to.

[RR_Mel]

The expansion damage I experienced was enormous.  It blew out 10” to 12” of both rails in three places on my single loop helix with a 32” radius.  Every curve on my main line blew out.  The plastic rail spikes were gone for close to a foot in every curved section of track.  The pressure from the expanding rails had to be enormous to destroy that much track, Atlas Flex Track is pretty tough.  I had to replace 11 three foot sections of track.  Half of the bad track was inside mountains and very hard to get to.

 

I learned a lesson the hard way and this thread was meant to help beginners by passing on possible problems that can be avoided.  If you don’t have a heat problem do it to it.

 

Like Chuck I no longer solder joiners, to each his own.  Now I drop short #20 solid feeders from each track section to larger bus wiring below my layout and use 1/32” to 3/64” gaps with Walthers 948-841 joiners and I no longer need to solder the joiners.  I solder the wires to the bottom of the rails so that they are out of sight.

 

Mel

 

 

Modeling the SP in HO scale since 1951

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

[Colorado Ray]

The coefficient of thermal expansion for nickel-silver is 9x10^-6 (0.000009) inch per inch per degree F.  For a 32 inch radius loop the circumference is roughly 201 inches.  For a 10 degree F temperature swing, the total change in length is 0.018 inches.  Normal rail gaps should easily accommodate that.  For uncontrolled spaces with larger temperature swings, the effects would be proportionately increased.  Brass has a slightly higher coefficient at 0.0000104 to 0.0000116 depending on the alloy.

Wood parallel to the grain has a very low coefficient at 0.0000022 for white pine. However, for across the grain the coefficient is 0.000017.  So with wood, it's not the temperature; it's the humidity/moisture content.  

The coefficient for moisture expansion of wood depends great on whether it is quarter sawn or flat sawn.  For white pine an average coefficient would be about 0.002 inch per inch per % moisture change across the grain.  Much less along the grain (0.00025 using the same ratio as for thermal).  Climate controlled spaces typically only vary within a three to four percent range.  So that 201 inch loop might expand and contract by 0.2 inches.  Again, unheated spaces may vary over a greater range.  Therefore sealing the benchwork in those spaces would be critical.

Ray

 

[richhotrain]

Confusing thread.

What causes expansion?  Temperature swings, humidity swings?

Both? Neither?

Expansion of what?  Track? Benchwork?

How severe is the problem?  I have a Midwest basement layout. Basement is centrally heated and cooled, seasonally, no dehumidifier. Atlas flex track nailed onto 1/2" plywood.  I don't solder rail joints.  I have not experienced an expansion problem in the 11 years that layout has been up and running.

Is soldering all rail joints the problem?

Rich

[mobilman44]

Hi,

My current and previous HO layouts are in a spare bedroom in a climate controlled house in southeast Texas.  Six months after laying track on the current layout, I walked into several distorted track areas that happened "overnight".  It was the plywood drying out (shrinking) that caused it.   I had thought the wood was all dried out, but obviously it was not.

The good news is that most of the track came right back in place with a slice from a Dremel cut off wheel.  Three areas had to be rebuilt however.

[carl425]

mobilman44

It was the plywood drying out (shrinking) that caused it. I had thought the wood was all dried out, but obviously it was not.

It's one more example of "lumber ain't what it used to be".

Last summer I had a new deck built out back.  I noticed that the guys were butting the decking boards tightly together. Since I had been taught years ago when I had the energy to do stuff like this myself that you needed to leave a gap between the boards, I asked them about it. The contractor told me that if they left a gap, by the time the wood had finished shrinking pets and small children would fall between the boards.  Sure enough, a year later the boards that were installed tightly together now have a gap of about 1/4" between them.

Imagine what 1/4" of movement in 6" would do to your track?

Fortunately for me, I move slowly enough that all my lumber has a chance to acclimate to the train room before it's used.

[RR_Mel]

Colorado Ray

The coefficient of thermal expansion for nickel-silver is 9x10^-6 (0.000009) inch per inch per degree F.  For a 32 inch radius loop the circumference is roughly 201 inches.  For a 10 degree F temperature swing, the total change in length is 0.018 inches.  Normal rail gaps should easily accommodate that.  For uncontrolled spaces with larger temperature swings, the effects would be proportionately increased.  Brass has a slightly higher coefficient at 0.0000104 to 0.0000116 depending on the alloy.

Wood parallel to the grain has a very low coefficient at 0.0000022 for white pine. However, for across the grain the coefficient is 0.000017.  So with wood, it's not the temperature; it's the humidity/moisture content.  

The coefficient for moisture expansion of wood depends great on whether it is quarter sawn or flat sawn.  For white pine an average coefficient would be about 0.002 inch per inch per % moisture change across the grain.  Much less along the grain (0.00025 using the same ratio as for thermal).  Climate controlled spaces typically only vary within a three to four percent range.  So that 201 inch loop might expand and contract by 0.2 inches.  Again, unheated spaces may vary over a greater range.  Therefore sealing the benchwork in those spaces would be critical.

Ray

 

 

Thanks for the great info Ray, I was hoping an mechanical engineer would get on board.

 

You need to add more track to your formula.  There is an additional 12’ of straight track attached to the helix on both ends so the total is 489” of track into two additional 32” radius curves and another 70” of straight track with the 70° swing.  There is a grand total of 660” of track in that mainline that buckled with the 70° swing.  Also keeping in mind the 70° swing occurred over two seasons per year (in Bakersfield we only have two season, very hot and cold) for several years.  I would estimate from original laying of the track to the “explosion” was 6 years of the track in motion.

 

I didn’t mention the disaster included two Atlas turnouts in my yard.

 

I’m a EE so this in not my forte, providing that heat expansion is linear I came up with a total expansion of .549”.  Forcing a secured material slowly a half inch at HO scale to me would be equal to something similar to a California Earthquake measuring 8.0 on the Richter Scale.  And that my friends is what my layout looked like.

 

I’m glad to see input on humidity, new layout builders need that info too so that they can curb future problems.  Building a model railroad can be almost as complicated as the real thing.

 

Mel

 

 

Modeling the SP in HO scale since 1951

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

[IRONROOSTER]

On a prior layout in a prior house I had track blow out when a humidity problem developed in the basement.  I had soldered all railjoiners except insulated which were tight.

Currently, I run dehumifier in summer and humidifier in the winter.  Both are set for 45%.  Temperature is set for 70 degrees year round.  Layout is still in early stages but I am planning on not soldering all the rail joints - just those on curves.  We'll see.

Enjoy

Paul

 

[floridaflyer]

I'm with you Paul, along with sealing the benchwork, I only solder the curves sections. Living in central Florida I do have a bit of a/c in the summer months, keeps the garage in the low 80's and helps with humidity. In the winter months, no a/c or heat to the garage. although the temperature is less in the winter, humidity could still be a problem. With gaps in my straight sections I have yet to experience any problems, going on 8 years now. Gaps are the solution to any problems, be they rail expansion or benchwork expansion or contraction.   

[mlehman]

Being Mel lives in Bakersfield, the humidity swings are far less severe than the temp swings he documented. I'd say this is a case where temp is the primary factor. Admittedly, humidity is likely the more common culprit in most places, but I doubt it is in Bakersfield.

I do solder some rail joiners for short sections of track when it doesn't really need a separate feeder. But generally, I leave the joiners loose. Never had an issue except for one time when a heavy rain left a larger than normal puddle on the basement floor and sprung an insulated joint that had been in place 20 years. That was definitely humidity. The outside of the foundation was subsequently regraded and not had any more problems.

[Regg05]

I've been watching this thread closely since I'm in the process of building a layout with someone in my unheated garage where i live in the greater Chicagoland....I'm using homasote for my roadbed and plywood for the open grid benchwork.  Do I need to be concerned about the humidity or more so the temperature.  I was going to by a dehumidifier in the fall when the prices usually go down at Lowe's or Home Depot.  Do I need to use a wood sealer on the open grid benchwork??? 

Regg

[riogrande5761]

mlehman

Being Mel lives in Bakersfield, the humidity swings are far less severe than the temp swings he documented. I'd say this is a case where temp is the primary factor. Admittedly, humidity is likely the more common culprit in most places, but I doubt it is in Bakersfield.

Thats what I was going to guess - you know, Bakersfield CA should be dry right?  I grew up in Davis CA where I remember humidity - at least in the summer in the 10-15% range - very dry!  So out of curiosity I google Bakersfield CA:

https://weatherspark.com/averages/29736/Bakersfield-California-United-States

Humidity

The relative humidity typically ranges from 21% (dry) to 94% (very humid) over the course of the year, rarely dropping below 14% (very dry) and reaching as high as 100% (very humid).

The air is driest around June 19, at which time the relative humidity drops below 25% (dry) three days out of four; it is most humid around January 9, exceeding 91% (very humid) three days out of four.

Whoa!  Not as dry as I thought and in fact it can get darn humid?  Did I read it right?  In the winter months it looks like it hovers up there more than I would have guessed.  Just goes to show you it isn't just the east coast or mid-west.

[RR_Mel]

mlehman

Being Mel lives in Bakersfield, the humidity swings are far less severe than the temp swings he documented. I'd say this is a case where temp is the primary factor. Admittedly, humidity is likely the more common culprit in most places, but I doubt it is in Bakersfield.

 

 

You got that right Mike! 

 

Humidity is definitely not a factor in Bakersfield.  Yesterday afternoon the humidity was 11% at 95°, not bad.  We occasionally get humidity spikes.  When we get a westerly breeze with rain clouds it get miserable here.  One day last week at 104° the humidity was 88%, extremely rare here.  The next day the humidity was down to 38%.  The spikes apparently don’t stay long enough to create a problem with wood, only humans.

 

We occasionally get a rainstorm, I think that’s what they’re called.  Typically 6” to 10” storms, that’s a drop about every 6” to 10” apart for maybe 5 minutes.  Sometime the concrete even gets wet.  Earlier this summer we actually heard thunder (no rain just thunder), thunder is very rare here.  Our average rain fall is well under 2” per year and it is like clock work, middle of December to early January.  Normally a continuously slow almost fog like mist.  With the heater running the humidity inside is always very low.

 

 

Mel

 

 

Modeling the SP in HO scale since 1951

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

[mlehman]

Regg05

I've been watching this thread closely since I'm in the process of building a layout with someone in my unheated garage where i live in the greater Chicagoland....I'm using homasote for my roadbed and plywood for the open grid benchwork. Do I need to be concerned about the humidity or more so the temperature. SNIP

Regg,

Yeah, you're going to want to do something to limit humidity. The best thing would be to air condition the garage, which has other benefits, of course

You say it's unheated, though, so I suspect you'd need to insulate it. A vapor barrier, usually plastic or other sheeting is also a good idea.

A humidfier will have a hard time keeping up with Midwest level humidity, plus it warms the air, not a good combination. A/C is a very effective dehumidfier, plus gives you cool air.

People tend to focus on homasote as being an issue many times. It's actually not that bad when it comes to absorbing humidity and changing dimensions. With a rise from 50% to 90% humidity, dimensional change is only about 0.25%. That's about a 1/4" over the length of a 4x8 sheet.

http://www.homasote.com/products/440-Soundbarrier.aspx

Often, wood may expand that much or more. So painting or otherwise sealing the benchwork is a good idea in a case like yours.

[TBat55]

I thought I did allow gaps (business card thickness), I did not solder rail joiners and I used DCC feeder wires every section I laid.  What got me was the PCB board ties I used to keep ends of flex track from bowing or kinking.  Same as soldering joiners!

Now I use PC board ties soldered to rails (or joiners) to keep the gauge or keep multiple ies straight - BUT I do NOT glue down the PC ties.  I let them float by shimming before ballasting then removing the 0.010" shims.

[TBat55]

Related topic ... use of shim for different track manufacturers.

https://im1.shutterfly.com/media/47a5d624b3127cdeea80756b290200000010O08BatXDZq5bg9u3Gg/cC/f%3D0/ls%3D00007956855020150805170425965.JPG/ps%3D50/r%3D0/rx%3D550/ry%3D400/?tn=2021810383

 

[crhostler61]

I live in a high valley (4300 ft elevation) in northern Nevada, year round average humidity is about 20%. My garage has no more or less humidity than the rest of the house. 9 years ago I built a large layout in my garage and had the track down in mid october when the weather was dry and temp averages in the 70's. I had not soldered my track at that point and when the winter set in and my garage reached 38 degrees all the track separated. Since it was too cold to do the needed repairs I waited till late April when the temps got into the 70's again. Then I soldered all the flex track and some of the sectional. Summer came around and the first day we had century mark temps, my garage hit 118. Unforgettable! And the humidity was 7%. All the track on the layout was severely heat kinked, most of the flex track damaged beyond use. I gave up on that layout and took it down.

My layout now...started in 2011. Occupies my living room, dining room, and part of my kitchen. The temps go as low as 60 in the winter and with no AC can get to 105 in the summer...low humidity all the time. All the flex track is soldered and I only see minor heat kinking on one area of my layout on the hottest days of summer. 

Humidity does have and effect but I live in the desert. Heat is the culprit. And it does directly affect the track.

Mark H

[davidmurray]

Regg05

gg05 wrote the following post 2 days ago: I've been watching this thread closely since I'm in the process of building a layout with someone in my unheated garage where i live in the greater Chicagoland....I'm using homasote for my roadbed and plywood for the open grid benchwork. Do I need to be concerned about the humidity or more so the temperature. I was going to by a dehumidifier in the fall when the prices usually go down at Lowe's or Home Depot. Do I need to use a wood sealer on the open grid benchwork???

Regg there was a thread about unheated garage as a layout space in the Chicago area on here a few years ago.  I remember because it was the first time I replied.

The consensus was that insulation, including in the ceiling, on all the walls, plus heating and air conditioning would be advisable.  Inside ate garage as few days every summer will bake your brains.  Some winter days/evenings will give you frost bite on fingers and noses.  Not good for enjoyable railroading.

Dave

[ROCK MILW]

Very interesting thread as I am building a layout in our heated attic (boiler/radiator-type heat, not forced air) and just last weekend encountered a number of locations where the newly laid flextrack had bowed outward.  My wife and I live in Minnesota and last weekend we left town.  The outdoor temperature dropped down to -14 F and the relative humidity dropped to approx. 53% (max. of around 73%).  Of course the indoor temperature ranged from 60 to 70 F, but the outdoor air was very dry (air at -14 F can't hold much water vapor).  This was the coldest air of the winter thus far.

The layout is constructed with 3/4" plywood "ribbons" supported by risers on 1x3 joists and 1x4 L-girders, with cork roadbed and Peco flextrack.  The track is glued to the cork with DAP Alex Plus, and all rail joiners on curves are soldered, as are some on the straight sections (not many of those as its a curvy layout in a 12' x 13' space).  I soldered the flextrack into 6' or 9' sections and then soldered each of those to the track already in place before curving them to the required radius.  What that meant for me was that there was a short (approx. 6" to 9") section where there was no glue holding the track to the cork, as I didn't apply the glue until I had worked the track into the required radius, then I pulled it back a little to apply the glue (Peco flextrack is forgiving with that).

Last Monday when we returned there were approximately 12 locations where the track had bowed outward, all located where there was no glue holding the track to the cork, or directly adjacent to those locations (in the latter case some of the track was pulled a little bit off of the glue).  I have replaced those "unglued" sections with glued sections.  I used the Kalmbach benchwork book instructions on purchasing the wood (AC plywood, kiln-dried, etc.)  I am guessing that the wood shrank last weekend due to the very dry weather.  If the relative humidity was 53% with a temperature around 0 F, when that air is heated to 60 F the relative humidity will be even less.  Plus my wife and I weren't in the house last weekend to breathe a bunch of humidity into the air.

I will be cutting gaps in the very short straight sections--I hope this prevents track pull-aparts when the humidity rises again and the wood expands.  The attic space will have a room air conditioner in the summer but I won't run it all the time, so it's bound to get quite humid when the outdoor temperature rises into the 90s with high humidity.

Any ideas?  What about the portions of the curved track at the soldered rail joiners, where there are no ties underneath the track?  Should I somehow attached the rails to the roadbed to prevent movement there?  Or should I leave it as is?  This is an interesting issue to deal with, here in the middle of the continent where the temperature and humidity vary so widely with the seasons.