Laying perfect track -- is Pelle Soeborg correct?

[sparkingbolt]

My 2 cents worth. I used plywood for framing, particle board for sub roadbed, homasote for roadbed all 3 are not affected by humidity Length-wise. I live in central Oregon, not to be confused with Oregon where it rains a lot. Here, east of the mountains it remains very stable humidity wise, on the dry side. I don't need to worry 'bout no stinkin' swell and shrink. Hah! Lucky me!

I laid my code 70 and 55 without gaps, and thought I'd be fine. The temperatures in Central Oregon are another story, they can and do vary 50 deg from day to night occasionally. My layout is in a finished, sheet rocked insulated outbuilding. I heat it now, but heater is still optional. I never let it freeze.

Welp. guess what? Early in my layout construction the temp swings wrot absolute havoc, tore up my home made switches and kinked what little section of hand laid track I'd gotton so far. Thankfully this was early enough to save what could have been way more work.

I redid everything, repaired the switches and used Micro Engineering flex track, no hand laid ('cept the switches) this time left suitable gaps, especially at switches. Since then it has endured from 35 to 95 degree temp range with no problems

So, Whether you have humidity variations or thermal variations, or both, build accordingly, and be safe, err on the safe side.

[Anonymous]

If you attach plywood to a solid framed wood framework-like L girder construction- you could experience some movement of the structure as a whole. Wood expands across the grain, and causes problems in cabinet and table construction. In my woodworking shop I use either slotted holes or metal fasteners such as "figure eights'", or small angles that ride in a milled slot, to allow for seasonal movement. Plywood is stable because of the grain orientation. Man-made products such as particle board, Homosote, and medium density fibreboard (MDF) are also stable unless they soak up moisture. I use MDF for shop jigs and for inner cores of workbenches because it is a cost effective, totally flat, extremely dense (& heavy), stable surface - but it must be coated w/paint, an oil, or a w/ shellac to keep the humidity out, first evidenced by tell-tale mildue in the Georgia hot and humid weather where I reside.

In the building of my new layout I am going to use some form of a fastener that allows for seasonal expansion and contraction, and use laminated pieces of plywood for the subroadbed, rather than real wood. Also, I suspect that the problem w/ kinked rails is aggrivated by tight radius curves and complex trackwork; consequently, I plan to isolate the sub roadbed for such sections of trackwork from the rest of the structure to permit the movement to take place off of the actual roadbed. The roadbed will remain intact-hopefully- while the wood frame moves about. We shall see. . .

[Don Gibson]

Is Pelle correct? Not Completely:

Rail when hot (warmed) will expand while the plastic ties will not - and produce movement by the rails lengthening and shortening. IF plywood absorbs any moisture (doubtful) it would be at the edges and would affect the thickness. Homosote on the other hand has exactly this problem. it's pressed cardboard and affected by humidity - at the edges.

Answers to Humidity: Location, De- Humidifiers, and avoiding joints over joints.

Now back to RAIL. It get heated by RUNNING! Go run some night with the lights off and notice the arcing under the wheels (CLUE?). BEST Answer is to allow for expansion and contraction of the rails , and friction fittting rail joiners to hold the rail, and not soldering them. Connect EACH section of track to an unbroken buss wire - and again, avoid joints over joints.

I know there are some that will post "They have never had a problem" - which they will trumpet - until they have that problem. I hope they never do. I have had layouts in The humid Midwest, So Calif., Denver (no humidity), and now Portland. Where did I have a problem? - A climate controlled basement in Denver. Go figure.

[nslakediv]

i agree with spsmoke. rail moves, plywood does not.

[Anonymous]

When the track kinks it is not from humidity or the wood base swelling . Wood will swell in dampness & shrink in dry hot weather but only until the moisture content is removed after about a season after milling. Plywood has no moisture (only glu) and wont swell unless you soak it in water yourself. Most of us use some sort of roadbed on top of the wood sub base & this is flexible, so dont blame your benchwork if your track kinks. Quite simply it is caused by the metal rail getting hot & expanding. Kinks will be most noticable on tight curves as the rail naturally pushes outward. I use 42" radius curves, solder my rail before laying & have very little problem. I do leave small gaps at the end of the curves on a straight section. My layout is in an uninsulated garage & summer heat is over 100 degrees at times. Pelle is wrong when he says to not leave gaps. It may work for him in his location but others will regret it.........Paul (spsmoke)

[dknelson]

By "heating season" I read Soeborg to mean winter --when the furnace is on and when the house is presumably the driest. If he meant the warm (summer) season then I agree with him but that is not how I read his article
Dave Nelson

[Anonymous]

Hooray for California! Practically no high humidity!

[fiatfan]

My track/bench are not allowed to expand or contract! [:o)]

Actually, I don't put in gaps and don't seem to have a problem. I run a dehumidifier from May to Sept. In the spring and fall, when it's too cool for the air conditioner and too warm for the furnace, I have a small electric heater. So the room actually stays at a fairly steady temperature and humidity year 'round.

As was said earlier, whatever works for you.

Tom

[IRONROOSTER]

I don't know. I laid track then had to go buy a dehumidifier a year later because I started getting a little mildew on a chest of drawers. Didn't seem to affect the track, but I had left a gap on one side so maybe that helped. Since It doens't seem to affect the trains, I do it; but only on a tangent.
Enjoy
Paul

[skir4d]

Here in Nevada you would never get any track laying done if you waited for high humidity (and that being 40 or 50% relative at best). I let the plywood equilabrate for a week or two in the garage and then use it. Even if the humidity gets up high enough for the wood to swell it won't be there long enough for it to happen.

Jack W

[nslakediv]

I live in N.W. Ohio. When I lay track(mostly on 3/4" painted plywood) I will leave a small gapabout every 2or 3 sections of flex. I will create a slip joint, that is I will solder rail joiner on end of flex track and then just slide rail joiner on to next track pc. My layout is in my finished garage, I would consider it much like a house. Heated in winter, sometimes I A.C. in summer but mostly just enjoy the fresh, until the lights have been on a couple of hours. I have only had 1 major kink, that happened when I pre-built a 5 track staging area on the ground, it was spring time and kinda cool, I allowed for summer expansion but not enough and ended up with a nasty 5 track kink. But was easily fixed with dremel and a cut off wheel. So dont be afraid to have plenty of expansion.

[BRAKIE]

Funniest thing about laying track..Everybody has their own methods, techniques,dos and don't.[:D] I live in Ohio and I find it is unnecessary to gap my rails for expansion from the humidity.The same applies to the club that I am a member of..Yet there are those who swears it is necessary to do so even though it has been proven other wise by hands on experiance.[.[:D][tup]
So the solution is to find what works in YOUR case and stick with that given and forget what the "experts" so called may have to say after all they are not always 100% correct.[}:)][:0][:D]

[Anonymous]

It depends on your summer.

Summer here IS the humid season. Pelle's advice works in Toronto. It may not work if your humid season is not summer, but typically summer is the most humid season anywhere near large bodies of water.

[orsonroy]

Heat has very little to do with track. It's the humidity that screws with it. Track is made of metal and plastic, two materials that are affected VERY little by normal atmospheric conditions (mind you, track in direct sunlight WILL expand). The problem is the wood, which is a sponge to water. IN some areas around the world, the hottest season IS the most humid (like central Asia, and here in central Illinois!). In other places, spring and fall may be the most humid but not the hottest. It all depends on where you live.

If you're laying track on a wood base, it's best to either do so during the most humid conditions possible in your layout room, or leave a few expansion joints. I prefer to keep small gaps at the switches, and solder all flextrack joints, except on VERY long, uninterupted runs (20 feet or more). Sealing the wood with two or more coats of latex paint will help to minimize the wood's movement, but leaving gaps is still a very good idea.

If you're laying track on a foam base, you don't need to leave gaps at all. Foam is dimensionally stable, and won't expand/contract with humidity changes. My layout is basically all foam, so I don't need to leave gaps. I do so as "extra insurance".

[dknelson]

Pelle Soeborg is one of the finest model railroaders around and I, obviously, am not. Yet I question something in his July article on laying perfect track. He says that when laying flex track during the heating season there is no need to leave gaps between pieces of flex track. He says gaps are only needed when the track is laid at other times because of the effect of heating season on the plywood or homasote roadbed.

To my mind -- and again he is the genius and I am not -- this seems exactly wrong. Seems to me things shrink during heating season, and expand during the wet/damp/unheated season. Thus it seems to me you need gaps during the heating/dry season and that those gaps will tend to fill in when dampness causes expansion of the roadbed, to avoid kinks.

It seems to me track laid during the damp season could have smaller gaps than that laid in winter. His advice seems more like what the prototype railroads care about -- they are more concerned with expansion of the steel rail in the heat than we are.

What Pelle Soeborg says in the article (on this one topic only) seems counter intuitive and just plain wrong to me. Anyone else have an opinion?

I might add that while I have two dehumidifiers going during summer, there is a period in spring when it is still cool in the basement because the furnace never runs and is too cool to make the dehumidifiers run correctly. My basement is probably dampest in April and May, and gets better as the temps go up in June through September.

Dave Nelson.