Firt of all I'm new to this so be easy on me. I am just about ready to start building the benchwook for my layout and i was wondering is 2" foam on plywood a bit overkill? I hope i will get some good advice from everyone
Jason
I'm new as well but that is what I was told. I'll probably use 2 inch sheets so I can go down to a set 1 inch in places... it's also cheaper for me that way since 2inch is more then 2x as much as 1 inch
Dave
Monolithic 2" extruded foam is quite strong. It is at its edges that it is weakest, so if you want to bond it to something else, that would be the place to do it...except I would used masonite or arborite, or somthing along those lines...thin and durable. This would be for the purpose of finishing and protecting the edges of the foam so that it doesn't suffer over time as you lean into the layout or grab ahold of it for support (you'll do that more than once).
If you lay the foam across a benchwork outer frame, as in to set it into the frame to keep it in one place, and then support it with joists spaced every 18", you will have a very strong layout surface. Gluing that much foam over plywood is not serving much of a purpose in my view. If you are worried about marring the nether surface of the foam, then sheet it with luan or masonite, maybe wall board or 1/4" plywood. Anything more than that is just more dollars for no real gain.
Other opinions that involve more work and more material will also require you to shell out more dollars.
I use 1/2" plywood with crossing bracing on 12-16" centers. This provides sufficent support for the cork roadbed and track. But foam on plywood is useful for carving away sections for below track scenic features such as creeks, drainage ditches, etc. You can also cut sections of foam and stack for hills. On the larger layouts you can have sections that are lower with bridges and streams.
Enjoy
Paul
Jason,
I have 1-1/2" foam encased by a wooden frame of 1 x 3s and supported with 1 x 3 joists as my layout base.
Click picture to enlarge
As Crandell said, extrude foam is amazingly strong but still lightweight.
Tom
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