Its the dreaded wiggle season again.

[michaelstevens]

With the NE's first snow storm, prolonged freezing temps and the central heat drying out the household air -- sure enough, I've got my first wiggle -- in track work completed during this past construction season.
My HO flextrack is hand tensioned, nailed and white glued onto 1/4" ply roadbed, which in turn is yellow glued onto 1/2" ply, glued or screwed onto 1x2 or 2x4 risers.
So that I fully expect this to happen, each year, as the new lumber (especially the 1/4") dries out and shrinks.
I know that "homasote" and other road bed materials are supposed to prevent this phenomenen. But I prefer the structural characteristics of 1/4" ply.
But what's interesting is that once I've fixed each wiggle ( dremel disc cut both rails and heat both sides of gap before soldering) -- that is usually that and they don't return in subsequent winters.
Any other thoughts ?

[Big_Boy_4005]

Where did you find that unusual construction method, sounds like a lot of work and glue? All that glue may be transfering its moisture into the 1/4" ply as the glue dries, which may be the reason there is so much movement when the seasons change.

Actually homosote may be worse, it can act like a sponge. It could give you humps and dips.

Is your track ballasted? it may provide extra support for the track.

Do these wiggles cause the track to go out of guage? if the problem is severe enough the rail can break free from the ties.

Do you leave expansion joints in your rail? you should, soldering every joint may be asking for trouble.

Do you use insulated rail joiners or just gaps for electrical seperation? Gap closing can be a nasty problem if you don't expect it.

Humidifier in the train room, perhaps? May not be cost effective, or may cause bigger problems.

Fix it and forget it sounds like its working OK.

[michaelstevens]

Thanks # 4005.

"Where did you find that unusual construction method, sounds like a lot of work and glue?" -- I got it from the construction industry (laminated beams -- light, long and strong) and first used it when I lived in St. Paul, 15 years ago. I was trying (successfully) to save weight for portability (and the move to Phila.).

"the reason there is so much movement when the seasons change" -- is almost certainly because I don't wait long enough for the lumber to "season".

"Is your track ballasted?" -- Not yet -- I wanted to complete all visible track laying (which I now have) and let it go thru the winter cycle, before ballasting.

"Do these wiggles cause the track to go out of gauge?" -- not so long as I use a gauge template when re-soldering.

"Do you leave expansion joints in your rail? " -- Yes, usually at mid-points between power buss connections.

"Do you use insulated rail joiners or just gaps for electrical seperation?" -- gaps, with a spot of plastic cement, to resist the creep.

"Humidifier in the train room, perhaps?" -- had one of those electronic ones up there in Minnesota. It was in the living room. Damned if that white deposit didn't get all over the house, down in the basement and on the railheads.

[Big_Boy_4005]

Thanks for the detailed response. Sorry I couldn't come up with anything new to solve your problem. At least this question has gotten a good number of viewings. Maybe someone else found some usefull information here.

I understand the glue now. So, do you bevel the edge of the 1/4"ply to simulate the roadbed, or just leave it square and let the ballast cover it?

I haven't done HO in a long time, I'm into 3 rail O, so I can get away with murder on my trackwork (monster flanges are very forgiving) even though I try to do it right. I'm still debating what method to use, but I'm leaning toward foam insulation over 3/4" plywood, to keep the noise down.

Good luck, and keep killin them wiggles (least they stay dead).