Benchwork\Use foam on top or not?

[Anonymous]

I have completed building my benchwork. I built it out of 2x4's and topped it off with 3/4" oak plywood. My question is should I put a 2 inch layer of foam on top? If I use foam on top is it going to be dificult to mount manual ground throws and or undertable switch machines?

Thanks in advance.

[Anonymous]

Chris,

If you put 2" foam on top of the plywood, are you speaking of a 4 X 8 foot piece? My recommendation would be to cut the foam to follow the design of your layout. You might even want to go to 1" foam, especially if you plan to put a roadbed under your track. This will have the added effect of constructing a grade that's higher than the surrounding area - good for drainage, etc., as would be in the prototype. I'm hoping you won't need to drain your layout.

For ground throws, you can construct a platform that's the same height as your roadbed, or when you cut your foam, you can allow for the platform in your cutout.

For undertable switch machines, I'm presuming you're talking about something along the lines of a Tortoise or similar switch machine. If you use piano wire (available at your local hobby shop (LHS)), you can form it to whatever shape you need to actuate the switch. The Atlas under-the-table remote snap-switches don't have a long enough pin to reach up through the plywood and foam.

Hope this helps somewhat.

[Big_Boy_4005]

Wow, that's some heavy construction!!! I thought I was the only one who used 3/4 plywood, but I'm in O, and occasionally have to walk on my layout, and weigh over 300 pounds. I only use 1x4 framing, and BC common plywood.

Foam is nice, but given all that you've spent on the lumber, maybe you should just use cork roadbed under the track, and just use the foam for your terrain. It may be easier to keep your track work smooth and even with the plywood if you are planning any grades on your layout.

[CBQ_Guy]

QUOTE: Originally posted by Big_Boy_4005

Wow, that's some heavy construction!!! I thought I was the only one who used 3/4 plywood, but I'm in O, and occasionally have to walk on my layout, and weigh over 300 pounds. I only use 1x4 framing, and BC common plywood.

Foam is nice, but given all that you've spent on the lumber, ...

3/4" oak...whoa! Why not just stain the oak plywood so you'll have a train set running on a nice looking table top. I've heard a rumor you don't really need the scenery anymore, anyway, so it should fit right in with "modern" thought. [;)]

Good luck!

[Noah Hofrichter]

[#welcome][#welcome] ChrisNScale

Glad to have you with us. As for the foam, I plan to use it for my new layout because it will be easier to make rivers, cuts and fills, and valeys because you don't have to lift the track up using grades that can make it hard to operate if you have to make too steep of a grade (I know this from experience. On the layout I have I wanted to make A rock retaining wall along the track, and to do it I had use 3-4% grades[:(], Not A good thing as I discovered later).

Hope this Helps, Noah[:p][8D][:D][:p]

[Fergmiester]

QUOTE: Originally posted by Noah Hofrichter

[#welcome][#welcome] ChrisNScale

Glad to have you with us. As for the foam, I plan to use it for my new layout because it will be easier to make rivers, cuts and fills, and valeys because you don't have to lift the track up using grades that can make it hard to operate if you have to make too steep of a grade (I know this from experience. On the layout I have I wanted to make A rock retaining wall along the track, and to do it I had use 3-4% grades[:(], Not A good thing as I discovered later).

Hope this Helps, Noah[:p][8D][:D][:p]

Noah has hit the nail on the head.

My Adventures alone today back this up as after checking a gradient on a section of spline I discovered I had a 8 to 10% grade. After much hesitation and consulting the Oracle (MR Forum) the replies recieved verified my worse fears. I have reduced the grade to 5% and the lower main line which the spline crosses over has been lowered about 3/4" to allow enough clearance between levels. This was done in an afternoon only because the main line was on foam, which allowed me to shape and change the lie of the roadbed quickly and without the recipricating saw.

[dknelson]

If you have a flat top layout there is an advantage to a layer of foam or other soft material on the top and that is you can model more topography BELOW rail level,, such as drainage ditches, creeks and the like. Sometimes it is not always practical to cut into the plywood top using the cookie cutter method to model topography.
Now to my mind two inch foam sounds like a bit much -- consider just how deep you want to go. Maybe one inch foam would do the trick.
I have not gone this route - rather my track is laid on a mix of plywood subroadbed and then cork and that elevates the track enough that the surrounding plywood is well below track level. Some buildings will be built up to that level, some will not be. For truly lower effects such as a deep quarry or creek, I added a layout segment where the table top is considerably lower and will built up the roadbed to match the rest of the layout.
Dave Nelson

[Anonymous]

At the moment I'm also using foam to model my layout. Using big sheets makes it possible to get results in a very short amount of time. I use it on my h0 layout on a benchwork with a grid of 16x16". The foam is stron enough to carry a doubletraction of Genesis SD70's the heaviest locomotives in my collection.

[Anonymous]

2" thick foam is strong enough, if supported properly(support beam every 2 feet), to be used alone for the benchwork top. you really don't need a plank of plywood if you plan on using foam. if you've got a plank of plywood, use that as your base and build up from that, as needed, with foam for hills and other such things.

Jay