11-05-2009, 11:53 AM
MountainMan Wrote:I'm surprised that one of our more technically advanced members hasn't figured out a way to measure the expansion in his layout using altered conductivity or something.
Interesting challenge! I don't know how to even start this, but I do have some observations to add, based on the modular group I belong to, and other layouts I have seen.
The modular group uses styrofoam decking in a pine or plywood frame. Modules are subject to differing storage and transportation conditions, but remain relatively unaffected - the transportation causes far more problems than humidity or heat do. I am thinking that's because:
- The track is laid on styrofoam for the most part. Styrofoam is unaffected by either moisture or heat.
- The individual lengths of modules is 4 feet. Even if the frame expanded due to humidity (wood being relatively unaffected by temperature), it's only over a 4 foot length, and the frame would have to pull away from the foam to which it is solidly glued. Plus the wood is painted with several coats of paint, inside and out, before installation of the foam. Paint can act aas a moisture barrier.
At home layouts, I think a fair assumption is to say that most of us want to spend the money on the trains. So buying the best lumber is maybe not on the radar, and the benchwork is put up as quickly as possible in order to get to the "good stuff". Wood available at the big box stores may not be dry, and may be affected before building by where it's stored. Once built, how many of us paint/seal all the benchwork before moving on? Sure, the top of the uppermost level gets covered, but a lot of moisture gets slopped on when doing scenery too. Add to that that many layouts are in the basement, which sees the most humidity (if not temperature) swings and it is not suprising that we think the track has moved.
Andrew