track expansion

[Sperandeo]

Hi Ron,

My approach is to solder rail joints in curves but not to solder them in straight track. I use the edge of an NMRA gauge to space the rails apart inside the unsoldered rail joiner in straight track. Soldered or not, I don't depend on rail joiners to carry current, and solder feeder wires to every lengtth of rail.

If you do get an expansion kink, from heat, humidity, or whatever, cut the rail near the kink with a cutoff wheel in a motor tool. That will usually be enough to relieve the kink, and you can put in additional rail joiners and feeders as necessary to maintain alignment and continuity.

So long,

Andy

[scubaterry]

I have been hearing about track expansion/contraction for quite some time now and always wondered how humidity could effect Nickel silver? With several of the above posts it is now clear in my mind. It makes perfect sense that it is the benchwork that changes forcing the track to change not the track itself being the problem. Putting a good coat of paint on all of the benchwork sounds like a good idea to me. Particularly as my train room is an attached shed here in the Florida Keys and I only turn on the Window AC units just prior to working on the layout so it is god awful hot in the shed most of the time. One of those things I really never stopped to think about. Thanks for the info. Just as a side however I solder on all curves (I use flex track) and solder most of the other joints leaving a gap here and there. I have feeders dropped about every two feet or so way more than I need but I like to overbuild. So far after six months down here I have noticed no track shifting and I like the added assurance of good track contact with the soldering. And I love the suitcase connectors. Just started using them on this layout and what a time saver and it looks neat too.
Terry

[orsonroy]

Track expansion is mostly a myth in this hobby. Does metal swell and contract with heat? yes, but to no real extent in a normal household. The REAL problem with expansion/contraction is with the benchwork material, especially untreated wood, which can move as much as 1/8" over the course of a year.

Instead of gapping rails a lot, I suggest adding a couple of coats of paint to any wood on your layout. Do have SOME unsoldered gaps in your track, but for better electrical flow solder MOST joints. I find that the soft Atlas insulated rail joiners work acceptably well as track gaps, especially if I leave .001" or so space between the center insulator and the rails. I gap at all diverging switch tracks, so I've got more than enough gaps for any expansion on my layout, which is foam based and really doesn't swell at all.

[dehusman]

By the way, its not the track expansion that's the problem, its the benchwork underneath. Think about it, why would you care about a dehumidifier if it was a rail problem? Brass or nickle silver doesn't absorb water. But the benchwork does. The only place I solder joints is in the middle of a sharp (less than 24") curve.

Dave H.

[Jacktal]

My suggestion is a small gap (.015-.020 in) every two to three feet.And since you have already installed feeders at these lengths of track,it will be a piece of cake to do.However,I wouldn't fill these gaps with anything,as I feel it defeats the purpose of the gaps,which is allowing expansion.Also,I don't think that electrical insulation is much of a concern,as only a major expansion could create a problem.

[cheese3]

I solder my joiners and I like how it keeps things nice and smooth. I am not worried about expansion.

[Texas Zepher]

QUOTE: Originally posted by selector
However, I am not so confident that the styrene gap fillers won't defeat the purpose of the gaps.

Exactly, and also without a railjoiner for the rail to expand and contract back and forth in, one loses all the "smoothness" the soldering was attempting gain in the first place.

QUOTE:
Gap your rails with a Dremel wheel. Try for between 1 and 2 mm.

The dremel cut off disks make such huge gaps, 5 to 9 scale inches wide. I prefer the thin saw blade either on the dremel or manual ones like the Atlas and Xacto saws.

BTW - I have never soldered track joints unless it is in a continuous curve. I think soldering is a hold over from the old days when people would wear out their railjoiners with temporary layouts before they made something perminant. So they soldered to fix it. Today with all the quality equipment and building materials we have, and since we put an electrical feed to each track anyway, I believe it is just a waste of effort.

[selector]

I think you have it all figured out; do as you describe. However, I am not so confident that the styrene gap fillers won't defeat the purpose of the gaps. It won't compress much, so why place it there at all? Gap your rails with a Dremel wheel. Try for between 1 and 2 mm. Once you have cut about six or eight gaps around our layout, I don't think you should worry about rails contacting each other or bending out of shape.

For what it is worth, I began to build my basement layout in Jan 05, right in the middle of my wood furnace heating season. That furnace is 19" away from one corner of my layout. I managed to get it pretty warm down there. No problems. I stopped heating in March, and had no hint at trouble until I did a double take at my long bridge, and saw that the flex-track segment across it had bowed hard to one side of the deck. What the...?! It occured to me that the basement had taken about a week to build humidity as it rains a lot here until late April. I purchase a mid-capacity dehumidifier and the track returned to its normal position within four hours.

[2021]

Looking for a couple of opinions on dealing with track expansion due to heat. So far I have soldered all my joiners and connected feeder wires in each 3-foot section (Have run about 35' of double track). I have a dehumidifier in the layout room (20 x 20). I wasn't overly concerned about expansion until I talked to one of our club members who doesn't solder his track for fear of expansion damage.
My thought is to continue to solder joiners to make sure of the smooth transition and then after ballast is applied, to cut both tracks with a rail saw and leave this small gap for expansion if necessary. I would probably do this every four sections. What do you guys think of this approach? By the way if I go to different districts I would epoxy styrene in the gap for insulation integrity.
Ron K.