Foam Board Insulation Bench Work

[jarnett]

I am beginning a new 4'x6' HO scale layout and have a question about using Foam Board Insulation as the layout surface. 

My layout will not be permanent but rather be either resting or temporarily attached to legs or a cabinet. Although a 4'x6' layout using 1/2" plywood as the layout surface, wouldn't be prohibitably heavy and unmanageable, I am leaning toward using the Foam.

In the Model Railroader book "How to Build a Model Railroad', Kent Johnson describes the process for using 2" Pink Foam Insulation Board as the layout surface for the 4'x8' O Scale Cascade & Timber Trail Ry, supported by 1"x6" MDF Fascia around the edges. Although not stated, I am assuming that the open grid consists of 1"x4" boards to support the surface.

In the Bachmann book "EZ Model Railroads", Chris Lane describes the 4'x8' HO Scale Iowa Central RR bench work as a laminated sheet consisting of sections of 1" thick Foam Insulation Board glued together, resulting in a 2" thick layout surface. This surface is supported by open-grid bench work.

I like these ideas, due to fact that it is sturdy and lightweight. 

I cannot find a 2" thick piece of Foam Insulation board at my local Home Depot or Lowes. Instead, they carry 1/2" and a 3/4" sheets. I could follow the Bachmann approach and laminate 1" thick Foam Boards together for a 2" layout surface, or is there another (easier?) option?

If I build an open-grid bench work with a 1"x4" frame, with 1"x2" cross members, can I use a single sheet of Foam? If so, should I beef up the frame?

Any suggestions would be appreciated.

Thanks,

Jim

[MisterBeasley]

My 5x12 foot HO scale layout, or at least the part I call Phase 1, started like this.

It's a wood frame, with 1x4 boards on the outside and 1x3 boards going across, with a single 1x2 strung diagonally to maintain the rectangular shape.  The 1x3s align with the bottom of the 1x4s, so the foam sits down inside the outer frame by 1 inch, and is better protected.  The legs are 2x3, secured with triangular plywood gussets.  I put casters on the legs that make it easy to roll around, even on the carpet.

Even at this size, the frame and foam is very light.  Be aware, though, that adding scenery, track and trains will make it a lot heavier.

[jarnett]

Thanks. That looks nice and clean. I like the idea of the 1"x2" diagonal to brace it. The photos really help!

jim

[mlehman]

1" foam supported on 12" centers is generally strong enough to support what most folks place on the layout, But be cautious about letting others near it, as it's all too easy to assume it's a wood-like surface. It's not and is relatively easy to punch a hole through it. So it can work, just that it has some limitations. I wouldn't go any wider than 12" on center support, for instance.

Sounds like you live somewhere generally warm, as many lumber/big box stores don't stock 2" in places like Texas and AZ. Usually, it's available special order, but may be hard to get if you don't want more than a couple of pieces. 2" is far more mechanically robust and is fine on 16" centers.

Speaking of the support center-to-center distance, keep in mind that for a human to pop up through the surface, 16" works a lot better for adults than 12" does.

And if thinner sheets are all that are available, it's not too hard to bond several sheets together to get a thicker, stronger base.

[cowman]

Laminating two pieces together is quite easy, I use inexpensive latex caulk to bond mine.  It holds well right off, but you can still adjust your pieces to line up as needed.  I let it dry over night before working with it, but I'm not sure that was necessary. One thing, if you use the 1/2" or 3/4" you will find a thin, clear film on one side.  Be sure to take it off before putting the two pieces together.

I have a 4'x6' HO layout at the moment.  Two passing sidings and a two track siding.  Not much, but sure is a great place to practice techniques and have some fun.

Good luck,

Richard

[jarnett]

Thanks richard

[BR60103]

I built a pair of 4x8 sections for an O gauge layout. I used 2" foam but had to match 2x8 pieces.

My frame was a rectangle of L-girders with the flange on the bottom (1x2) and 1x2 cross pieces at 16" centers. I probably could have used plain wood.

The layout is supported on a bunch of plastic sawhorses.

[Donald50]

Jarrnet, I am glad you asked the question on Foam base surface on open grid bench work. As I am also looking to do same except on a modular HO scale layout 8' x 8' ( 2' x 4' modular bench work ) to make it light enough and transportable in the event that I move or when I move when need be in the future.

[BigDaddy]

There was a recent thread about looking for foam in So California.  The big box stores can get it but you have to buy 50 or 60 sheets.  The insulation guys have it but they want to charge you double the cost.

I have the same long range plan and used this MR idea for plywood bench work with 2" foam on top of a thin 1/8" piece of luan plywood I had lying around.  Used wing nuts to fasten the legs. 
At the time I posted about it, some people didn't think the plywood was necessary at all. I think it did add some ridgidity to the benchwork.

http://tinyurl.com/y9ur43lh

 

[kasskaboose]

2" foam is great for layouts.  Finding such a thickness seems challenging, so I would suggest using 1" sheets and adding another layer to create higher elevations (when needed).  The problem with 1" is you can't make deeper valleys, etc. versus 2" foam.