Hi All, A first time poster here. I have been obsorbing information form this site for quite a while which has been so helpful and have over about 12 months progressed my layout quite well with a few dramas along the way. I now have over 80 metres of n scale flex trackand 45 turnouts layed, wired for dcc and about to put in all the block detectors. I have what I think may be a problem looming with the track in that the gaps where the track has joined have opened up considerably (almost 3mm in places). The track was mainly layed in summer when the temperature is around 90F and now in winter (40F) I have considerable gaps. I am looking for advice as to how to deal with this. Would it be a good idea to solder the joints to fill them and hope there is no buckling in the warmer weather? If so what would I do at breaks in the track for the blocks, perhaps a glue of some type to fill the gaps? Any advice would be greatly appreciated. Thanks Rob
Be careful about soldering all the joints. The rail is going to expand and contract with temperature. If you don't let it have a place to do it, it will move the track. Actually the real answer may be more gaps, not fewer. spread the expansion and contraction among several small gaps, rather than concentrate it in one big one. Another thing that will affect track is the wood used in the base. Wood expands and contracts with changes in humidity. In most cases the the changes in hte wood can be more than the changes in the metal.
I had the opposite problem. Putting down track in cool weather and having it expand in the warm weather causing the track to develope kinks. You could make a Dutchman, a small piece of rail with the base filed off. placed in the gap and soldered in. But the rail may expand when your season changes, so if you can silde the joiner open put in a small piece with the base on so you can remove it when the rail expands. You could also cut gaps on both sides of the opening and slide the rail a little from each side to close the gap. You will have to solder feeders to those rails to avoid dead track.
Hi Candy The train is in a an outside garage. I am in Adelaide Australia, Temperature variation in the last 12 months has been 36F last week to 112F back in January. Rob
I thought you might be in Australia because you said it was winter. We just had the first day of summer. Can't you insulate your garage or something to keep the temps from swinging so much. Maybe you can heat it a bit in winter and AC in the summer. ....36 to 112 ! You Aussies are hearty men! Candy
Don't forget humidity. This will make the wood to expand. And I think this is more important than the expansion of the rails. Wolfgang
I'd agree on Wolfgang that humidity is at least as big a problem, if not bigger. My layout is in a seperate building that I do not heat/cool except when I am in there or when operations are happening. Last summer, I noticed mold growing on my scenery. Put in a dehumidifier and it ran for a month while I emptied it twice a day. At the same time, I noticed the track had buckled in several places. KB
Changes in the gaps left for rail 'expansion' and 'contraction' are almost entirely due to changes in the wooden benchwork, and those changes are near 100% due to changes in ambient humidity. Someone here posted back in 2007 or earlier that the coefficient of expansion for NS rails is something like 1/4" in 100' over a 30 degree change in temperature. If all you see is a total of 1/4" in 100', and that is spread over umpteen gaps, then no one gap would show more than maybe 10 thousands of an inch in change. So, it's the humidity. If you are heating now, and were not when you erected the layout, the wood has begun to dry. Drying wood shrinks along the grain, and when it does, it tows along the tracks attached to it, even if indirectly attached. So, gaps that were reasonable six months ago may be nearer to 1/8" or a bit more by now. FWIW, I am currently running two dehumidifiers in my basement, one droning not 14 feet from me as I type. It's a fact of life in a basement with non-sealed cement floor and sand soil outside. Five months from now I'll have a humidifier running because I heat the house largely with a wood furnace that sits literally 18" (the minimum for local codes) from one corner of the layout. It gets hot in this room, which means the relative humidity drops commensurately. The wood in the layout can be heard creaking and cracking if I don't run the humidifier. It's just the way she goes.....
Mind the Gap I'll echo the above comments about coping with humidity changes by soldering feeders to every rail. I try to solder flex track pieces when the joins are on tighter curves, but only every other join or two on straighter tracks. I live in Central Illinois and my layout is in my climate controlled basement so temperatures rarely go beyond low 60sF in winter or above 80sF in the summer. But what causes all the problems is changes in humidity: when humidity is high, my track is fine, but when the layout dries out, I've had turnouts ruined and yard tracks that looked like a skier's slalom run. One winter I got fed up with the kinked-up track and managed the humidity with two portable humidifiers I got at garage sales....Worked like a charm...track straightened right out (mostly). The biggest kinking occurred the first year in our home (2003) when I had laid flex track on new (moist) Homasote in the humid summer and everything dried out in the fall and winter. I had to clip off rails to get it straightened out. A year or so later we had an unusually dry and cold winter and everything shank even more, necessitating a little more Rail Nipper work. More recently, when dryness leads to kinking, I've just gotten back into the habit of monitoring water levels and refilling the humidfiers more regularly. A few years ago we had a thread debating whether kinking was caused by heat/cold expanding/contracting the metal rails or if parched and shrinking subroadbed was causing the kinking. Here's a pic I posted to support the humidity-shrinks-the-subroadbed-more-than-the-rails-which-kinks-the-rails hypothesis. Two new pieces of Homasote were originally laid down touching each other and covered with ground foam, but over time, they shrank and there is now a large gap. Note too that I had to cut out a piece of track on 2 of the tracks to insert a fill-in piece to bridge the gap. 4 to 6 feet to the right of this gap, toward the other end of this 8 foot long Homasote sheet, I had to nip some rails/tracks shorter to repair kinking by turnouts because the track configuration didn't allow me to shift rails in those tracks toward this gap.
Only if the foam, of any thickness, is free-floating on a frame that might be susceptible to expansion and contraction due to humidity. If the foam is somehow securely adhered/affixed to the framing under and around it, something will give. I would expect seams to part where slabs of foam abut against each other at the level where they are affixed to the frame. Or, a really thick foam that can't separate or split may force the wooden frame members to split. But shrinking wood will want to move. So, you could have 1/4" foam that wouldn't budge at all if it were allowed to float freely in a box framing around it. That is, the thickness doesn't matter...it is the suspension of the medium on which the scenery is placed if that medium is not itself susceptible to changes in dimension due to heat or humidity.
