# Layyout "no warp" material



## choochootrains (Jun 2, 2012)

My 4x8 layout base is built. I now want to put 3 removable top sections on it. What thickness & type of plywood or other material would be strongest, light weight, and will not warp. Thanks .


----------



## tjcruiser (Jan 10, 2010)

Polystyrene insulation foam (the "pink stuff" or "blue stuff" sheets) would fit the bill nicely ... light, won't warp. Strong enough to support a likely layout weight, though not someone stepping on it, of course. Strength/stiffness also depends on your support spacing underneath.

Foam is readily available in 1/2", 1", 2" thicknesses.

TJ


----------



## gunrunnerjohn (Nov 10, 2010)

I'm curious about the "removable" statement, what do you mean by that?


----------



## choochootrains (Jun 2, 2012)

*Layout "no warp" material ***Removable Question Reply****

I want the layout base and top separate. I want the top in 3 sections(4 x3, 4x2, 4x3) instead of one large 4 x 8 piece. The reason is to make the layout easier and less damaging to move(lighter than if it was all attached and easier to brak strutures off.) Also one section could be changed and/or replaced in the future or lifted to work on the wiring underneath. Also instead of all the wires hanging underneath they can be between the base top and the top top with one opening in the center of the base top layer for the wires to drop straight down to the control shelf underneath the layout.


----------



## Big Mike (Dec 2, 2011)

tjcruiser said:


> Polystyrene insulation foam (the "pink stuff" or "blue stuff" sheets) would fit the bill nicely ... light, won't warp. Strong enough to support a likely layout weight, though not someone stepping on it, of course. Strength/stiffness also depends on your support spacing underneath.
> 
> Foam is readily available in 1/2", 1", 2" thicknesses.
> 
> TJ


 
I like this stuff,but I had a little trouble with the weight of my "o" scale on it though,so what I did was Liquid nailed a sheet of Leion 1/8 " thick ply wood on one side,it was still very light and now strong too.
of course with HO or N, I don't think there would be a problem,JMO.....Mike


----------



## tjcruiser (Jan 10, 2010)

Happy to hear that....

I calculated a while back (but never actually tried it) that a "sandwich" of 1/8" ply, 2" foam, and 1/8" ply would be substantially stronger, stiffer, and lighter than a comparable sheet of 3/4" ply. The I-beam effect, with the structural material (the 1/8" ply) positioned far away from a "neutral axis".

You have a skin on just one side, but for the weight of any trains, I think you'll be fine. Just don't jump on it yourself!

TJ


----------



## Big Mike (Dec 2, 2011)

tjcruiser said:


> Happy to hear that....
> 
> I calculated a while back (but never actually tried it) that a "sandwich" of 1/8" ply, 2" foam, and 1/8" ply would be substantially stronger, stiffer, and lighter than a comparable sheet of 3/4" ply. The I-beam effect, with the structural material (the 1/8" ply) positioned far away from a "neutral axis".
> 
> ...


yea, I don't think it would hold my weight , I never tried to step/or walk on it.
but for trains ,even scale sized ,lashed up diesels shows very little to no flex,of course I did use some supports under it,down to the main table.
mine was 1/2" blue dow board with 1/8" ply wood only on one side,I think if you sandwich 2" dow with 1/8"ply on both sides,you can walk on it ,I have some 2" ,I walk on all the time with out hurting it,I intend to use some of the 2" for a mountain or something one day...........Mike


----------



## fotoflojoe (Dec 31, 2011)

tjcruiser said:


> Happy to hear that....
> 
> I calculated a while back (but never actually tried it) that a "sandwich" of 1/8" ply, 2" foam, and 1/8" ply would be substantially stronger, stiffer, and lighter than a comparable sheet of 3/4" ply. The I-beam effect, with the structural material (the 1/8" ply) positioned far away from a "neutral axis".
> 
> ...


Makes total sense TJ.
If you think about, your calculated material is analogous to sheetrock: "structural" paper surrounding a gypsum core. The materials, when combined in the right way, are many times stronger than either one used on its own.

Edit: NOT that I'm advocating the use of sheetrock as a layout deck material!


----------

