I’ve been building a “replacement” HO 11x15 two level layout since last January, and have the lower level complete, and one of the outer mainlines on the main level complete as well. Trackage is Atlas N/S Code 100 flextrack, laid on cork roadbed with 1/2 inch plywood base. It is housed in a spare “climate controlled” large bedroom. I have been in the layout room for two weeks and during that time we in the north Houston area had a 4 day cold spell (cold for here), the worst since '83.
Well, today I got back into the groove and ready to lay more track. Ha, that was not to be, for I had 4 or 5 places of track warpage that needed to be fixed. I’m in the process of doing that, and also cutting in some track spaces every 8 feet or so with a Dremel cut off wheel.
As I never had this problem on the previous (very similar) layout (1993-2008), I didn’t feel the need to put in “spaces” as this layout was being built. Of course I will do so as future track is laid.
I do have some questions…
Is it the rails themselves, or/and the benchwork that is affected by temperature & humidity changes?
If I did nothing, would the track “automatically” straighten itself out when our normal temps/humidity return here?
Do you feel the spaces cut into the rails every 6-8 feet is a good solution, or is there something else I could do that would work “more betterish”?
Thank you all for your time and expertise. Needless to say this is a real downer after all the time and effort I put into making those “sweeping” curves and easements and arrow straight tangent sections.
A bit off topic but since you are in Houston, you should come to the Petticoat Junction model rr club meets at Valley Ranch BBQ at 249 and Spring Cypress every first Friday of the month at 6:30. It’s free and there are people from all scales. It’s a good time.
Same problem last year when I got a little carried away with the soldering iron. I tried to solder as many joint as possible on an older layout but found that I had to repair several spots when the temp dropped.
It is the bench work that is shrinking with the lack of humidity. The rail would be slightly affected by temperature but not enough to measure.
I left the older benchwork and track alone to see if it would work itself out after a period of time (4 weeks actually) with a portable humidifier in the room but if it made a difference, I couldn’t tell.
On my current layout, I solder every second rail joiner in a staggered fashion attaching feeders to every solder point and try really hard to have the unsoldered joiner on a fairly straight section of track.
So far on the new layout I have only had one area of trouble and that was fixed by sliding back the rail joiner and trimming the rail. This is on a new layout with new benchwork and 3 weeks of Minus 20 degree celcius weather.
In answer to Mobilman 44"s cutting the rails with a Dremel cut off wheel; I recommend that you use joiners on the cut rails, and leave a space for expansion and contraction (of the benchwork). If you do nothing, you will have the same problem repeatedly! I solder none of the joints and have feeders soldered to every section of flex track. Bob Hahn
I have built 7 HO scale portable modules that get dragged around to shows and other clubs in all kinds of weather and I can tell you it is not the rail. Painting every piece of benchwork and every surface of it as well will help some. Unlike others I never solder the joiners and run feeders to every rail even on curves and turnouts. I had hastily built a 30 inch X 48 inch module using clear pine outside frame and only painted the visible wood and left the inside unpainted. Inside that was a 2 inch piece of foam with the scenery and track all glued on and done up. The wood frame had expanded that I could lift the foam out. It chewed up the foam where it was bonded and cracked the scenery that was done. All my other modules are painted everywhere and show little expansion and contraction. It does not pay to rush the project. It will always come back to bite you. Cutting gaps and unsoldering your joiners will help but it only masks the real problem with the ever growing and shrinking benchwork. It hurt my heart when I saw the scenery cracks in that module.
I’ve heard this story many times on the fourms. I’ts the bench work that is affected by moisture drying out of the wood. The best cure; a little late now; is paint all wood parts of your frame and plywood. This helps stop moisture changes in the wood. I know this is not a common problem where you live, but up here in michigan it’s a very common problem.
I did paint the lower level benchwork after the track was laid, but held off painting the main until I had finished with its trackage. I guess I’ll paint it shortly, as soon as I get the problems fixed.
The thing is, we have had the worst cold spell here since '83, and of course the heat has been on much more than normal - thus bringing the humidity way down. And as the wood was purchased this summer, it still had a lot of moisture (apparently) in it.
Like I said, I’ll cut in some gaps, and relay track as needed. I guess I should count my blessings in that I “only” have about 5 places to fix, and no ballast or scenery is in place.
You know, having worked in refineries for 40 years, I’ve been exposed to all the precautions made in piping to account for expansion/contraction. So I tended to think of the rail as being the problem, and discounted the benchwork.
I’m going to be something of a contrarian here, in that my rail expansion-contraction problems (which were allowed for by leaving gaps at my un-soldered rail joiners) are caused by temperature swings (50 F in 24 hours, 100 F in 12 months) not humidity. Humidity has no effect on steel, and I don’t use wood for benchwork construction.
Since I have built in un-climate-controlled places before, I was confident that leaving the gaps I did in new construction would allow the rails to slip enough to avoid problems. Happily, I was right.
By way of contrast, I had some track laid on wood planks which had been staging on my last pre-move layout, built in climate controlled space. When the humidity here dried the wood, it warped - and the track, laid with hard-butted joints, looked as if I had used a sidewinder for a straightedge.
While a swing of 100F may well be enough to get an actual noticeable expansion of nickel silver rail, not too many people experience 100F temp swings in an indoor living space. However you do get plenty of humidty swings when you go from cooling the air to maintain 72F to heating it to maintain 65F. That temp swing won’t generate a measurable expansion in nickel-silver, but the humidity change can and will cause relatively large movement of wood and other moisture-containing materials like homasote. steel studs and extruded foam in a reasonable (human comforatable) environment should NEVER have any of these issues.
If Houston is anything like Atlanta this year, you are probably having the same problem I am having (and other modelers in my area as well). Although the tmperatures have been way below normal, it’s actually the long spell of low humidity that is the culprit in Georgia. In 2009 we had record rainfall and the humidity was constantly high–I had to add a dehumidifier to the basement that ran constantly. When the cold spell came, the humidity went rellay low. My benchwork is less than two years old and is now drying out in the dry air. As a result, I am getting track pops that I have never had an issue with before. I use acrylic latex caulk to attach the track to my roadbed. Also, I gap EVERY section of flex track, but the wild swing from moist to dry has caused so much benchwork shrinkage, I still got track pops. I have been dealing with this by tacking the loose sections back down with superglue. Will be interesting to see what happens when the humidity goes back up in the spring. Jamie
Well, it looks like I’ve got company in experiencing this warpage for the first time. Those of us down south near the Gulf usually have some degree of humidity year long, but heating up during that cold spell sure did take the water out of the benchwork.
I’ve planned to spend the day fixing up the problem areas, and once done (and tested), I’ll get out the paint brush and paint that upper level.
More Info- I just took a closer look at a section of track that has really popped up; it is arched up probably a good 1/2" to 3/4" over the roadbed. At first I thought maybe I frogot to gap this section of track, but a closer look reveals the gaps are there, just closed from the benchwork shrinkage. This particular section is so bad I am going to have to do what the real roads do when they get a sun kink: cut out a small section of rail and join everything back together. This should not be too bad since there is an adjacent turnout and I never solder the rail joiners at turnouts. So I’ll slip the joiners back, nip a bit of the rail off the end of the flex track, lay a fresh bead of caulk and join everything back together. I will monitor this section closely in the event 2010 turns out to be like 2009 in terms of the monsoon-like weather we had nine months of the year. I would think this would result in wider gaps as opposed to popped track. Jamie
Well, I finished the repairs and tested the results, and all seems to be ok. In a few spots, I only had to slice the track with a Dremel cut off wheel and it popped back into place. I added a couple of track nails and that should hold it just fine until ballast is added.
I had two of the worser kinks on each of two 30" radius “sweeping” curves. After messing with it for longer than I should have, I bit the bullet and just spliced in a new piece of 36 inch flextrack. I should have done that in the beginning, for IMHO, fixing track problems on a curve is often an exercise in futility. Anyway, all is well on the main level.
The lower level had one place that I gapped, but (thankfully) the rest appeared to be OK. Actually, mild warpage is not necessarily an operating problem, it just looks bad.
Ha, its drizzelled rain here for almost 48 hours, and I suspect “low humidity” will soon be a thing of the past…
This can happen no matter HOW solid you build your benchwork. In the club I used to belong to, they built extra strong - all supporting structure was 2x4 or LARGER and would have qulaified for a load-bearing wall in a residential structure. Subroadbed was 3/4" ply, with 3/4: homasote over top. Problem was, the first section was built int he middle of summer. The building was not air conditioned, so the doors and windows were always open. Building was basically atthe same 80-90 degree 95% humidity as the outside. Everythign was fine. Until winter came and the heat was turned on. Humidity dropped to probably 15-20%, maybe less, and EVERY track (did I mention this was a multi-track coal yard/power plant (loads in/empties out around the end of a penninsula), plus a double track main plus a passing siding?) buckled, despite none of the joints being soldered. Most of it had already been ballasted, too, and scenery installed on the mine side. Took a LOT of work by the track guys to get it all fixed (I was on the electrical crew…lucky me).
As I was putting in one of the replacement sections on a curve, I found the lost screw (sort of wedged between the ties) from my Bachmann 2-8-0.
As some may recall, from my “threw a screw” posting about 6 weeks ago, I was testing trackage using the new Spectrum going backwards with a string of Walthers passenger cars. Suddenly the side rod popped off and the loco rattled around and the thing ground to a halt. I spent hours looking for the screw and missing spacer (still missing) and wrestled with Bachmann for 3 weeks before I got a replacement. Ha, now I have a spare!!
I live in SW Missouri. Built an around the wall layout using 1x4 lumber in a honeycomb type structure; 1x4’s 16" OC. I hand picked the lumber and guess what…by the time I screwed it together, some of the pieces had begun to shrink & warp. I talked to the guys at the local model RR club here and they advised against using plywood, so I just glued 2" extruded foam to the honeycomb.
Got the roadbed & track down and so far…nothing is popping up, twisting or warping. I was concerned about gaps btw rails on code 100 flex but the guys assured me, I would need some kind of ‘expansion joint’ btw the rails just in case.
By the way, I’m the guy who emailed you some time back. Go Lane Go. Class of Jan. 1963.
Same situation with the weather up here in Austin with temps below 20 degrees, excluding the wind chill… My layout room is against an exterior wall, and suffered only one small (less than 1/64") shift in the track near a switch. One of the things I did to combat any shirnkage/warpage problem was to bring the lumber into the room where it would be installed and let is acclimate to its new environs (indoor temps and humidity) for a week or so. This helped greatly, and of course, I suspect painting it helped it even more. I use 19/32 inch plywood laminated with a 3/4 inch layer of blue or pink foam insulation board. I glue and screw the plywood down, supporting it every 12 inches and install the foam over it with Titebond. this all sits above base cabinets purchased from Home Depot, leveled and secured to the wall and to each other. Between some of the cabinets, a "bridge benchwork is made from poplar, also allowed to “rest” for a week or so before construction (thanks DonZ). This created the “bulletproof” benchwork that is mentioned so many times in Model Railroader, and also provides excellent storage for all my stuff. Upper decks are secured to the wall using lag bolts and are attached to each other. Each deck in insulated on its underside.
It also helps that when we built the home, we asked the builder to “double stud” the walls of the train room, securing them together and to the top and bottom plates. We also had all interior walls insulated, something not completely done in new home contruction on a regular basis in Austin. The home is also bolted to the foundation and the roof is installed with “tornado clips” and is protected with impact resistant shingles. I suspect all this overbuilding keeps the home from shifting too much which helps prevent the layout from shifting.
So the track damage was a good thing? Did you find any coupler springs or missing grab irons? Perhaps I should tear up some track maybe I will find a missing sock or something. LOL
On a more serious note it is good to hear you are up and running with little disruption.
You don’t need to paint everything but the rule is that if you paint one thing, you need to paint it all. That’s one of the reasons people use fascia boards on their layouts that is the type of info that has kind of been lost in time.