I sure didnl't mean to start a foam/plywood discussion in this thread. I just wanted to know why plywood was supposedly unstable.
In my experience, plywood is perfectly stable and suitable.
I have also used foam and had good results.
-Kevin
Living the dream.
SeeYou190 I sure didnl't mean to start a foam/plywood discussion in this thread. I just wanted to know why plywood was supposedly unstable. In my experience, plywood is perfectly stable and suitable. I have also used foam and had good results. -Kevin
You did not start anything and asked a perfectly reasonable question. It was the assertion that plywood is not a stable base for a model railroad that caused controversy.
I'm happy for all the foam users who like that approach - good for them. But we don't need to hear nonsense like "plywood is not stable" so they can defend their choice of foam.
Having done this for nearly all my life, I know what I want from my layout.
Here is what I don't want - a flat 2' deep shelf that that only models the 80' on either side of the tracks. So foam fails my design requirements on a number of levels.
Model railroad layouts can be built to be moved, with or without foam. But as I found out, with all my design and construction knowledge, as well 50 years of model train experiance, highly moveable/portable layout design requires a number of compromises - a great many of which I was not willing to make.
I'm still trying to understand why foam is considered "easier"?
I built a number of layouts with the once popular L girder approach. Now I just build an open grid, 2x4 lumber or 1x4 lumber depending on each situation. 1/2" plywood with 1/2" homasote for large flat areas, yards, cities, etc. And smaller plywood "bases" for large structures, etc.
And then any form of hard shell scenery - wire screen and plaster works as well as anything.
Hollow scenery means things like staging tracks can be under there. Room for turnout motors, electronics, relatively easy access to stuff.
I model the Mid Atlantic - we don't really have flat land here, and railroads are constantly going up or down minor grades.
Starting with a continious table top for that is counter productive.
And plywood with homasote works great. If it is not broke, don't fix it.
I'm building a large layout, benchwork requirements will be different in various areas of the layout based on track and scenery requirements.
In some places I will build a table top - with plywood - so my fat butt can climb/lean as required - because nearly all of it will be more than 2' deep.
It will all have to be strong enough to support my weight, and allow space below for hidden trackage - and access to that trackage.
Sheldon
At the risk of channeling the spirit of lastspike mike, plywood is intentionally made with crossed layers so it does not tend to warp or expand differentially with humidity or temperature changes.
But it still does expand and contract as a unit, if the train room temperature can swing between extremes or humidity isn't controlled. It is that potential action that produces the concern in this specific context: if jointed track is installed too rigidly to plywood that changes size 'differently' there MIGHT be operating trouble with electrical continuity, gaps, or buckling.
Hence the practice of dividing the rail into soldered-joint lengths, each with a high-integrity connection via feeder to a good electrical bus, with a few strategic joiners or gaps to accommodate any 'breathing' that might occur. Each modeler might have their 'sweet spot' between length of 'welded rail' and number of feeder drops and rail connections necessary.
I have become a firm believer in the thin-layer-of-adhesive-caulk method of attaching track to roadbed, whether it is connected with joiners or soldered up, as providing "enough" compliance to preclude track buckling or pull-aparts. That is discussed in previous threads here by more experienced heads than mine.
Overmod At the risk of channeling the spirit of lastspike mike, plywood is intentionally made with crossed layers so it does not tend to warp or expand differentially with humidity or temperature changes. But it still does expand and contract as a unit, if the train room temperature can swing between extremes or humidity isn't controlled. It is that potential action that produces the concern in this specific context: if jointed track is installed too rigidly to plywood that changes size 'differently' there MIGHT be operating trouble with electrical continuity, gaps, or buckling. Hence the practice of dividing the rail into soldered-joint lengths, each with a high-integrity connection via feeder to a good electrical bus, with a few strategic joiners or gaps to accommodate any 'breathing' that might occur. Each modeler might have their 'sweet spot' between length of 'welded rail' and number of feeder drops and rail connections necessary. I have become a firm believer in the thin-layer-of-adhesive-caulk method of attaching track to roadbed, whether it is connected with joiners or soldered up, as providing "enough" compliance to preclude track buckling or pull-aparts. That is discussed in previous threads here by more experienced heads than mine.
All true.
I have never built a model train layout in a crappy environment. Even when I built one in the attic of my 6 car garage it was a well insulated, heated and cooled finished space that remained stable in most weather even with the HVAC set on a "minimum" kind of temperature while unoccupied.
50' to 60' lengths of flex track all soldered joints never buckled, no expansion/contraction issues ever came about. Benchwork was a mixed bag combination of framing lumber, priemum 1x material, various grades of plywood, and OSB board.
DISCLAIMER - remember everyone, I am a DC modeler - I have multiple isolated track sections, commonly called blocks.
Each block only has single feeder for each rail, no "buss wire" system, because that feeder comes from a nearby relay panel, part of the sophisticated advanced cab control system. On a few bigger blocks (like 80' or more) expansion rail joints mid way are not soldered, but jumpers are soldered right at the joints (like prototype bonding).
Never any problems.
Most of my layouts, including my new one, have been build in Mid Atlantic region basements - all you need is a dehumidifier and you have a stable environment - 70 degrees, plus or minus 3 degrees, all year round.
If I live to be 100, I will never understand people who spend lots of money on things and then don't take care of them?
Model trains are expensive - I'm not leaving mine in sub zero or tripple digit temperatures, or damp/wet places.
Just like I will never understand the people who bought $10,000 GRAVELY garden tractors and let them sit outside?
Modeling goals and trends have changed in this hobby, but I don't follow trends.
Over some 5 decades I have known a large number of modelers with moderate to large DC layouts, all with soldered rail joints within each block just like me, and the reports of expansion/contraction issues is a single digit percentage to be sure.
AND, many of those modelers successfully converted to DCC by simply connecting to their existing block feeders, and NEVER added additional drops of buss wire systems.
One modeler I know, whos layout I designed and help build, was DCC from the start. It contained two large helix connections to a lower level staging yard. The taller helix contained eight loops, 36" radius, or about 150 feet of track for each of two tracks.
He dropped feeders for each 18' loop - but it was years before he got around to connecting them to the buss. The joints were soldered.
Not one expansion/contraction issue - not one operational issue, even before the drops where connected. Imagine that.
But what could I possibly know, none of my little trains have any brains.
PS - My track construction method - homasote sheets over 1/2 or 3/4 plywood for yards, etc, homasote milled roadbed for mainline raised ballast areas. Homasote sheets screwed to plywood. Homasote roadbed nailed down to 1/2 or 3/4 plywood or 1x subroadbed with a pneumatic brad nailer. Track glued down with clear PolySeamSeal adhesive caulk. Turnouts not glued, held in place by ajacent track and two or three track nails.
i made a 15 foot by 16 foot layout using 3/8 plywood as a base and foam on top, up to nine inches high .. i soldered all track joiners except for turnouts, and there i soldered on feeder wires on each leg
whatever works for you is fine by me , lol..
wvgca i made a 15 foot by 16 foot layout using 3/8 plywood as a base and foam on top, up to nine inches high .. i soldered all track joiners except for turnouts, and there i soldered on feeder wires on each leg whatever works for you is fine by me , lol..
And that works great if you don't have any hidden trackage below or behind your scenery.
ATLANTIC CENTRAL And that works great if you don't have any hidden trackage below or behind your scenery. Sheldon
actually i do have some hidden track [ in three places] but none is longer than five feet, and easily reached with a bent stick ... had to do it twice so i know , lol