I have never used Foam!

Model Railroader Layouts and layout building
1

Ok I have read some of the 22,656 hits I received when I did a search of plywood vs foam. I am leaning towards foam since I received a couple sheets of the 2” green at a very reasonable price. (FREE). I will be putting in on the ½” plywood base I currently have set up. I worry about being able to move the track and or cork if I need to make some adjustments. I did some experimenting last night and was able to remove the track without much of a problem but the cork came up with some of the foam.

My question is: Has anyone ever regretted using the foam after having a layout on plywood.

Thanks for your time.

2

when ever i have to pull up track to move it or what not the cork always takes chunks of foam with it i just fill it back in with plaster some time i leave it alone i look at it like this land isnt flat

no i havent ever regretted using foam (well what kinda foam)

3

Nope, no regrets. Now working on my second layout with a foam base. Try using less adhesive, and a not so hard one, to attach the cork to the foam - I prefer cheap latex caulk, using a THIN bead (the smallest mark on the caulk tube is TOO BIG, I cut well above there - such a small hole I need to use a piece of wire to puncture the inner foil seal) and spread thin. It takes very little to hold the roadbed or track in place. On guide, if you draw pencil lines to make the track centerlines before installing the cork, the caulk should be so thin that you can easily see the pencil lines. If the lines are obscured, you’re using way too much. If you look at the pictures of my previous layout, the 8x12, ALL of the roadbed AND ALL of the track including the yard consumed only 1 tube of caulk.

–Randy

4

I’m happy with it, too. I am starting Phase 2 of layout construction, and I’ll be using foam once again. I built simple box-frame benchwork with 16-inch rafters, and put the foam directly on top of that, no plywood.

I’m in HO. For larger scales, you might need more support, because the trains are so much heavier. For HO and N, though, that’s not a problem.

You can’t attach Tortoises directly to foam. You will need to do something like glue thin plywood underneath to provide support.

You can’t climb on top of foam.

5

I used foam (wrongly) on my first test layout, and I won’t use it in the future.

I found it loud (I had the foam supported in a wooden frame, not layered with another material), I also grew tired of working with the foam and the constant mess it makes. Not to mention trying to attach things to the bottom side (like switch machines).

On my second test or chainsaw layout, I moved to cardboard strip lattice work covered initially with masking tape, and than with either plaster cloth or a vermiculite mix. The cardboard is inexpensive, (I just used old boxes, so the cardboard itself was basically free) and fast - with a hot glue gun, you’d be surprised at how quickly you can create large terrain features. The tape covering also goes quick, and just provides a good base for the following plaster coat.

People note they prefer the foam as they can easily make lower than track level features; I found carving or rasping out a foam pond to be a lot more difficult than I thought it to be - and with what I’m using now, creating lower than track features is also not a challenge.

Economically, creating tall mountains or hills does require a fair amount of foam, and it’s not that inexpensive. It’s one thing to use it for facing on a cliff side, or a flat or low rolling hill structure, but to entirely support a large mountain requires a fair bit, reducing it’s economy.

I can see it’s appeal for a smaller layout (4x8, or shelf based, with limited terrain features), but for myself its advantages just didn’t pan out. I also have (limited) concerns on the environmental impact of the foam and it’s manufacturing, but that’s just an aside.

Naturally, if you can get enough to do what you want for free, than I’d say have at - although I’d still recommend a solid, if very thin, plywood layer under the foam.

EDIT - added a couple of pictures. I hope they can help you make a decision either way.

From my first test layout -

before

6

We used foam for the club layout. 2" foam on top of 1/4" plywood(attached with PL300 glue). Cork roadbed and track are attached with a contact cement. Everything went down very nice. Attaching ground throws and Tortoise motors required ‘pads’ we cut from 3/16" plywood. There has been no real expansion problems in the past 5 years. The noise or ‘drumming’ is noticable. A friend used foam with no plywood support underneath and has that ‘drumming’ noise as well. Another friend just built a layout with 2" foam on top of 1/4" plywood. He used Vinylbed and we will find out if he has been able to beat the noise issue.

My layout was constructed using traditional 1/2" plywood on L-Girder type of construction. I use Homabed glued to the plywood. The track is spiked to the Homabed. The layout runs very quiet. For myself; any future layout will use plywood/Homabed - it is much easier to install things like ground throws and switch motors. I have seen no cost difference between the two construction methods.

Noise elimination has become a hot topic with layouts as DCC/Sound is now everywhere. I’ll bring up another ‘noise’ issue - Ballasting. A lot of folks use diluted white glue to bond their ballast. It is much more inexpensive that ‘Matte Medium’. The problem I have seen is that the glue dries ‘rock hard’, and the layout gets ‘noisy’. Matte Medium dries to a ‘soft’ state and does not transmit the sound.

Jim Bernier

7

I have my 2 inch foam mounted on 1/2 plywood and cork road bed, quieter than the track at my LHS.

My only regret is my track plan. One section requires me to lean on the foam to get to it. My fat belly has made some depressions. Trains track well on this section, but I don’t like the clicking sound. Other than that I glad I went with foam base.

All so look for damaged foam at Home Depot, I have gotten 85% off! Last 2 inch thick 4 X 8 cost me $3.75, not the $25.00 list.

Cuda Ken

8

I’m not impressed with foam. I’ve tried it twice on a 40inch x 6 foot On30 Layout with marginal sucess and now on a 4’x8’ O gauge layout. It mashes easily and is not easy to attach track.

I won’t use it again.

9

I’ve used foam for my last two layouts. Will never go back to conventional wood riser, plywood and homasote. This way is cheaper, much easier and cleaner. - Nevin

10

I have never used foam and have never regretted never using it. Never, never, never.

Mark

11

My current layout is foam. I’m not impressed. It’s noisy, and a pain to mount things to. All my switch machines and ground throws needed special mounting pads.

For my next layout, I’m going back to plywood/homasote spline.

Nick

12

I have foam now and in the past. Like all mediums the are pluses and minus and have to weigh each for your project at hand. My only regret is the cost if you have to buy new and full retail.

By the way, I have never heard of green foam. Any brand name on it? Is it like the white bead board stuff? Just wondering

ratled

13

Ratled,

It’s called Green Guard from Pactiv Building Products out of Atlanta, GA. Says it’s FM approved what ever that means. I got it from a building contractor in TN. He had a couple sheets left over from a project and was just going to throw it away. For the price I said what the heck, I’ll try it.I bought a sheet of the Blue 1" several months back and it seems to be the same material. I seem to remember them having the Green the last time I was at Lowe’s, but at my age I don’t remember to well anymore.

14

I have built several layouts with traditional cookie cutter plywood and risers. My last layout and my present are foam on 1/4" plywood. I have become more and more disenchanted foam as I have used it. That said, foam construction has 2 major advantages:

  • Easy light weight construction. The two newest layouts were both designed to be portable, which dictated the use of foam. The other method that is light enough to be portable is thin (1/8" or 1/4") plywood grid, sometimes called waffle. It’s a lot more construction work than foam on or in a simple frame. On the Free-mo Yahoo group, a discussion of a simplified light plywood grid is going on. They are using 3/4" ply subroadbed with minimal thin plywood supporting grid.

  • Foam is easy to plant trees into.

I find traditonal cookie cutter to be a much easier way to construct layouts with hidden trackage or grades or tracks that are over top each other. The bent plywood readily forms grade transitions so that those are never a worry or a factor. The thin subroadbed (I used Homasote over 1/2" plywood) makes track separations reasonable without having to change track support materials. And, as has been mentioned, attaching switch machines or installing under the track uncouplers or running wiring is much easier with cookie cutter plywood.

I have found that carving below grade scenery in foam to be on par with various forms of plaster shell that I have used. I have used Plaster of Paris dipped towels on window screen, hard shell with Hydrocal, and plaster cloth over cardboard forms in conjunction with cookie cutter plywood. All have their advantages and disadvantages - and all are messy in one way or another. But for somebody who is now modeling coastal Oregon forest land, lots of trees are a scenic nece

15

My current layout is just over 25 years old, was built with plywood and homasote and homabed. We didn’t talk foam scenery in those days and I have no need or desire to change my layout just to be in. In fact, this layout is very likely my last, so the whole issue is a moot point for me.

Bob

16

I think there will always be pros and cons about foam. My latest (8 year old) and probably my last MR has been built on 1x4" framework with a foam base. It’s about 24x24’ and has elevations ranging from 45" to almost 72" at the highest point. It’s all constructed on foam. It went together quick and efficiently, and I’m very pleased with the results. And it’s quiet. When I run trains (I’m DC, and not into ‘sound’), all I can hear is the gentle hum of my can motors and the clicks of my cars on the rail-joints, LOL!

Let’s just say it’s worked out for me very well. Pros or cons.

As to re-locating track and bringing up chunks of foam with the roadbed, I use a thin layer of Elmer’s Carpenter glue to attach the roadbed to the foam, using small ‘T’ pins to hold the roadbed and track in place until the glue sets, which is usually in about 24 hours. Any track adjustments have been relatively easy and mostly mess-free.

Granted, foam is not the best solution if you are going to have to attach under-layout switch machines, but since all of my turnouts are within easy reach and I use ground-throws, for me that’s a non-issue. However, for those using switch machines, some adjustments with plywood panels under the layout will be necessary.

One thing I don’t do is ‘stack’ foam for scenery forms. I use the old tried and true method of wood frame, lattice strips, plaster cloth and ‘zip-texturing’ for my mountains. What stacked foam I have is used solely for grades and elevations. And of course, stacking the foam that way only increases its strength.

As I said, it’s worked for me very well. But that doesn’t mean it’s going to work for everyone. It’s pretty much an individual thing, and a great deal of it depends on your original layout planning.

17

Can’t attach Tortoises to the foam? Hogwash! I tried it out on my previous layout. Same caulk I used to glue down the roadbed and track adhered the Tortoise tot he bottom with enough strength that I was aftraid I was goign to break it when trying to pull it off - eventually I was able to bust it loose with a sharp rap and it pulled a layer of foam with it. You need to hodl it in place for a while for the caulk to se tup, but all that workign time means no issues with alignign it, there’s plenty of time to slide it one way or the other for perfect alighnemt, then clamp in place for 15-20 minutes and the caulk will be set enough to hold the weight of the Tortoise, Stick a clothespin or similar type of clamp on the throw wire up top just ot be sure. Next day, remove clamp, trim throw wire. The tortoise will NOT fall off or move under use.

Ground throws - small square of masonite or thin luan or airplane plywood, caulked to the foam. Screw ground throw to small plate same as you would attach it to a plywood surface.

Think outside the box - new material = new fastening methods. Roadbed and track - nails will NOT work with foam. Use a spreadable adhesive (hey - like caulk!). Putting down foam instead of plywood and then proceeding as if you were using plywood will in most cases produce unsatisfactory results if not outright failure.

To be honest, a long time ago I tried a layout with homosote and founf it completely useless. I have yet to see this amazing spike holding ability of homosote - all the track and roadbed I fastened down with small nails was easily pulled out when I dismantled the layout - I didn;t even need tools. I didn;t need tools to put the nails in, either (although after enough of them my thumb started to hurt from pressing them in so I resorted to pliers). Everyone talks about how great it is for handlaying track - but I challenge the idea that the homosote is what holds the spikes

18

Edit: sorry, I was trying to edit my post on my handheld, and wiped it. I won’t bother with the whole thing, but a few comments.

I disagree with Randy - when I started hand laying, I tried a bunch of different road bed materials, and homasote won out for spiking.

I also don’t think that using foam is in any way “thinking outside of the box” (a phrase I’ve come to loath, mind you). It seems that a lot of modelers now-a-days are either using it, or have in the past.

The best suggestion so far, is probably the hybrid approach.

19

Anderson Ind, I am from Carmel Ind my self.

My self, I have found it very easy to attach track. Lay down the cork road bed with caulk, then spike down the rails. This section of rail has been down for two years, no caulk to hold the track down, just spike.

Mountains are all so foam.

Cuda Ken

20

This being my first layout of any consequence and taking up a whole room I thought long and hard about what materials I was going to use. My wife is a vet so plaster cloth was easily available and I could get it for dirt cheap. It was the mess that I was worried about. There is expensive carpet in the trainroom and I was terrified of ruining it so it was foam for me. A quick vacuum and the carpet is clean.

Any holes in the foam that were caused by having to move the cork, I fill with caulk if they under where the cork is being moved to. Anywhere else they are part of the landscape.

One thing I do differently than what others appear to do, is when I am going to take the track from the cork to the foam for sidings is, I carve a trench in the foam and run the cork into the trench down to grade. I think it looks better doing it this way. Some people sand the cork down, but after trying both I get better results doing it my way.

I am planning to use plaster cloth on a small area just because I want to try using it. I see no reason you can,t mix and match.

One other thing I learned through experience is use a small rasp to work the foam. For that matter when working with the foam the smaller any tool I used gave better results.

Brent