Foam or no foam?


C

clayguthrie

Member
I have a brand new 4' x 11' table to build my ho layout on in my home office. Question is, should i put building foam on top of the table and put the roadbed/track on that, or should i just put everything directly on the table?

My understanding is that to have a ditch/stream/etc i need to build it up with foam and dig down from that , is that correct? Or is there another way to go go about this process?

Additionally, how well do the track nails hold the track and roadbed to the foam?

Thanks in advance.
 
Foam

Hi Sir;

I absolutely love the foam for a top piece. I can shape with a file or saw easily, and when putting track nails in, I just have to push them instead of the hastle of driving them into plywood or something else. I use my weller soldering iron with a loop of wire in it to cut the foam for lower level track, or rivers, ponds etc. and it works quickly and easily. The soldering iron makes it so there are no foam beads all over everything like a saw does. Neater. When I ballast the track, it is easy to remove the track nails so all that holds the track is the ballast glue. It's light weigth, I make mountains, ridges etc. with it, a little plaster over that, and I"m almost home free. Personally I'd highly recommend the foam route.:):D;)
 
The foam is excellent for armatures, utility poles, fence-posts, and for gouging out relief or stacking to get elevated relief. It is also a fair bit of work to achieve those ends, messy, and easily marred.

I would urge you to learn for yourself if foam works for you. I used it extensively on my first layout and enjoyed working with it. My results sucked, but it was my first ever layout, so whaddayawant?

On my second layout I tried spline roadbed on risers and scenery using aluminium window screen covered with ground goop. I also enjoyed that, but it still sucked because it was my first layout using that method. My impatience wasn't the least bit helpful either. A lot of work, slow results. I think I must have mixed over 140 individual batches of about a quart each of the ground goop to spread over the screen. I retained some of the foam from the first layout and used it on both ends of my around-me layout for built-up industrial and residential settings.
 
Here's an example...

I'm working on my second layout. I've chosen to use a foam base. Here is a sample from one corner that's pretty far along. You can achieve success with foam if you're patient, practice, and don't mind trying again. But the same can be said for any other method as well.

I wanted to have my main line raised above the base, so I used a constant height riser by Woodland Scenics. I covered the risers with plaster cloth and then used caulk to fasten the cork roadbed to the hardened plaster cloth. I also usually use the caulk method to attach the track to the road base. Your stream can be accomplished a couple of ways - you could raise the area to contain that stream and put the streambed at the base level. You could cut into the foam to form it. It really depends on the foam you choose and its thickness. I'm using the pink extruded foam made by Owens, which is 1.1/2" thick - plenty of depth for a stream.

I recommend you do what you did here - troll the forums out there, read, research, and then give it a try. My main reason for choosing foam was the ease of installation without power tools. My track plan was on one basic level, which didn't require the strength provided by plywood - the benchwork supports the foam. Good luck with it.


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I had a 2" foam base on my previous layout, but for this one I'm only going to use it for above-surface terrain. I had serious difficulty drilling holes thru the foam for the wiring, and getting signal posts to stand erect without an underlying wood base was near impossible.

But that's just my own experience - YMMV!
 
My vote for is foam. How you gonna create a river, stream, or lake without the foam base?

I have a 1.5" foam base on my layout. I love being able carve out rivers and streams.

My mountain was also made out of foam. First I made the base with peices of foam. And then I also used that spray expanding foam, to create a rocky base.
 
clayguthrie said:
I have a brand new 4' x 11' table to build my ho layout on in my home office. Question is, should i put building foam on top of the table and put the roadbed/track on that, or should i just put everything directly on the table?
Click to expand...
Totally depends on your goals. I first tried foam on a 4'x2' module. It has its good and bad points. Until you try you won't know for yourself, but I personally I built 3 new modules last summer. I used foam on all three.

There is of course another option. I have other modules where the track is directly on the strips of plywood sub-roadbed, but all the scenery is on just sheets of foam. The foam is NOT on top of anything but self supporting.

My understanding is that to have a ditch/stream/etc i need to build it up with foam and dig down from that , is that correct? Or is there another way to go go about this process?
Click to expand...
There are as many ways to go about that process as one can shake a stick at. Remember modelers have been doing this for decades before foam was invented.

Additionally, how well do the track nails hold the track and roadbed to the foam?
Click to expand...
Nails? I haven't used nails for about two decades. I use adhesive. Matte medium for glue specifically.
 
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Hi Clay,
Being from the Old School of thought my table work is the 'L' Girder type with wood risers to support the the 1\2" OSB base for the 1/2" sound board to be attached to and then either the cork road bed above that or as I'm tending to do now more is to lay/glue the ties directly on the sound board for a ground level appearance of the Older Rural line, 1890's - 1910 I'm trying to depict.

As far as using foam as a base it's probably not a bad choice as long as your not going to desire to have rivers or run off ditches or ravines deeper than the depth of the foam. Of course you could always get another piece of foam to go under the existing one too if you required more depth.

Using the L Girder, actually an inverted L across which stringers [l] are attached to which the Risers are then screwed to them to gain the elevation desired for the sub road bed/road bed. This gives me the added depth of at least the height of the stringers over the Lgdrs but if I require more depth I can even cut the Lgdr and drop it down and reattach it as I'm going to have to do to get a 7" deep run off wash across which a curved trestle will span to support the track.

So you can see it would be a hard thing to do that with foam without also cutting out a section of foam and it's supporting base and dropping down to gain the required depth.

Also I make my mountains by cutting cardboard to the general shape I desire placed every so often and then create a mesh work of other card board strips to form valleys in between and then crumple heavy brown shopping bags and lay that over the mesh work and apply strong paper towels diped in Hydrocal over that to form the hard form a base base to work from and it often looks fairly decent as is with all it's uneven surfaces.

At least when I apply the crumpled bags I can change the shape until I get it close to what I want or take it off and redo it.

So it's up to you which you feel is the best way to go.
 
So Clay - many different ways to do this - none right or wrong. Do your research and then give it a shot. There are also many, many videos on YouTube where folks show how they do things. I've done a bunch of research there and gotten different ideas how to do things - even though I might not follow the method shown.
 
Laying down a layer of foam as a base is a wonderful idea. I wish I had thought of it before I began laying track.

We all love the deep canyons and towering cliff faces, waterfalls cascading down boulder strewn slopes and other grand scenes, but it's the shallow drainage ditch running along the side of the road, the subway entrance steps leading down into an underground passageway, the construction trench, the cellar hole, the well and the many other small depressions and openings in the ground that makes for truely realistic scenes.

When we put track to plywood, even with a track bed, it's difficult to make below ground openings thus we tend to limit ourselves to making just the larger ones.
 
I like foam. You can do a lot with it and you can use just about any tool you have lying around. Those hot-wire foam things are great (smelly though) and they don't make dust like a saw does.

I've got a very small (like 1' by 4' small) layout, so my benchwork consists entirely of a piece of foam. I built up the taller stuff with the usual cardboard/plaster/newspaper route, and cut down into it with whatever was at hand (I dug out my water area with an old fork). I cut wiring trenches out from under it with a soldering iron and made some minor depressions in the top with a lighter flame.

As with any material, experiment with it before you glue it to something you care about. Wouldn't hurt to open a window either, given the smell the stuff makes when you heat it. But there's a whole lot you can do with it once you figure out how it works.
 
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