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Now I'm thinking about using foam board which I've never used before. I know it's popular as a 'fill' material for mountains or just to raise the area for a river or stream 'cutout', but I see many using it for the base itself.
Ok, since this is a somewhat large, narrow and long around the wall layout in N scale, what do you guys think of using;
just plywood?
just foam board?
foam board over plywood?
Also, what thickness of foam board?
Lastly, how about humidity and expansion and contraction due to temperature swings in a northern unheated basement?
I did just plywood on my layout but if I did it over again and had the money I would use foam over plywood. Just foam (IMO) is not sturdy enough to build on (I would think it too easy to break the foamboard when doing things on top!!!) but if you use it on top of plywood you can do so much more w/ scenery. All advice that I have seen is that you should use at least 1" stuff, maybe 2".
You will naturally be careful of the scenicked surface on extruded foam slabs, but the nether side needs both protection from gouges and knees, but it also needs to be able to afford a purchase/mounting surface for electricals, switch motors, legs, etc. So, it is best to sheet the foam with 1/4" quality ply to keep it protected.
How about expansion & contraction of foam vs just plywood?
Also, does sectional track expand & contract as much as plywood? IOW's by using foam, does that reduce/eliminate the E & C issue/problem?
Ok, using 3/8" ply (which I already bought), what is the thinest foamboard that I could use and how about under table switch motor linkage reaching the points?
I was thinking of using plywood and a bunch of foam on top for the same reasons OCN Guy mentioned. My question is how do you keep the plywood flat? I bought a bunch of 1200x1200mm sheets that I'll cut down to 1m², but every single sheet the hardware place had (in two different locations) were not flat. Some curve in the middle, others just bend one way, but none of them are identical. Has anyone else encountered this and how did you get around it? I'm not confident that just bolting the wood to the frame would be good enough to keep it level, which is very important for my modular design.
How about expansion & contraction of foam vs just plywood?
Also, does sectional track expand & contract as much as plywood? IOW's by using foam, does that reduce/eliminate the E & C issue/problem?
This is one advantage of using track sections, whether flex or sectional, over foam. You don't have to worry about expansion due to humidity changes in the wood around and below it. Heat expansion is negligible in changes under 20 deg. Code 100 NS track expands only 1/4" over a whopping 100' with a rise of 30 deg. Nothing that a few normal gaps at joiners won't take care of. Instead, it is the humidity that causes track buckling...a drop that makes the wood shrink, thus drawing the tracks closer with it.
Also, you would be using acrylic latex caulk to glue the foam to the plywood, so if the plywood wants to change dimensions, the foam can stay put and let the caulk absorb the stresss since it will be somewhat pliable.
you would be using acrylic latex caulk to glue the foam to the plywood, so if the plywood wants to change dimensions, the foam can stay put and let the caulk absorb the stresss since it will be somewhat pliable.
While I model in HO, I used 1/2 Birch plywood and 1 1/2 foam over it. Yes I can stand on my bench work, but don't need to. You need it to be able to carry any weight you might throw at it. 1/4" is probably OK IF you have enough support under it with the foam. 3/8" would probably be better.
In my case, the birch was actually on sale and cheaper than the lesser grade of plywood. I built basically 4 2' x 8' tables and then bolted them together to make my 8' X 12" square doughnut. Each table is built with 1"x4" framing and 2"X4" legs with adjusters.
Patrick, I have just started to build an HO layout, mirroring your use of 1X4s for the 24" x 48" frame and legs. This morning I went to the Home depot and bought a 2 x 4 piece of 3/8" sanded plywood for about $8.
I also saw that they had 1/2" and 3/4" 2 x 8 sheets of pink foam board, which I intend to purchase next.
I was wondering what type of adjusters you used and how you attached them to the legs. The Greatest Hobby you tube video recommends installing the levelers in small sections of 1" x 1" which are attached to the bottom of the legs.
I found 1/4 20 x 5/16 T nuts and levelers at Lowes, legs are done, frame is done, next step will be attaching legs with cross members and plywood to frame.
If you are considering foam, you have be sure it is fire proof. If in doubt, take a piece of the foam out doors and apply a match to it. If this stuff is petroleum based, it will burn like petroleum.
I've used 2-in foam alone successfully with shelf brackets and my current shelf switcher is a couple layers of 1/2-in (I think) foam laminated onto a hollow core door. I will probably expand, using the shelf as a starting point, but I think I'll laminate foam onto lauan or doorskin.
The HCD is actually overkill for my purposes but I would like to have a less "squishy" base to glue fascia attachment blocks to and so on.
Many people feel one should always build very heavy, solid benchwork but I went the L-girder, ply, and Homasote route on what was to be my "dream layout", only to see virtually all of it hit the dumpster when I moved. From that point on, cheap and light was my choice. YMMV.
No one will see it after the scenery.
