What are you using to fill in the seams of the blue foam insulation board?
I had to piece two togetther and have a seam to fill.
Thanks
Rich
Sometimes nothing. Sometimes the ground goop will do it. For larger gaps you can cut strips of the foam. Most plaster will do the job. Plaster cloth is recomended but is expensive over kill.
On my layout. I count on the ground goop or use the gaps as starta layers in the rock formations.
By the way, welcome to the forum.
Fill it with newspaper and cover it with lightweight spackling compound.
It depends on the size of the gap and whee it is. If it’s a fairly large gap, I use Great Stuff foam sealant. If it’s a small gap, I use latex caulk (which I use to lay track, and I lay track before I scenic the foam). If the gap is in a decent place for one, I just carve it into a stream or drainage ditch.
And don’t bother with the spackle; the whole point of using foam is so you don’t HAVE to use any sort of plaster.Start using it, and you might as well have completely traditional hardshell scenery.
Huh? I thought the point of using foam is that you don’t have to use wooden contours and chicken wire.
WS products suggest a foam/hardshell combo, and I’ve seen many club layouts that cover foam with hydrocal.
I guess I’m wrong then. Oh well, guess I have to quit the hobby now.
Woodland Scenics is a company that’s trying to make money. They suggest using a lot of their own products in an effort to sell you more stuff. Nothing wrong with that, but most of what they suggest is overkill.
There have been a LOT of threads on foam-based layout construction on this forum (and others). I’ve personally built four home layouts that were foam based (two for me and two for others), as well as 20 or so Ntrak modules that were foam-based, so I have a lot of experience with the medium, as well as lots of biases.
When you’re using form for a modular layout, light weight is the key, and is where foam shines. There’s really no acceptable substitute to foam when you have to schlep around a bunch of modules all over the countryside.
When you use foam for a home layout, especially a linear walkaround, shelf-style layout, then ease of construction is where foam comes into play. Ease of construction equates to making things effective, easy, cheap and FAST, while keeping the layout structurally sound. Adding layers of plaster over foam, whether it be spackle, plaster-dipped towels, or plaster cloth, adds more to the layout in terms of time, effort and money, and it’s not generally needed. You’ve already got the foam down and contoured, so why bother adding a hardshell layer to it? What’s the added value? More realistic terrain? Spend a little more time contouring the foam, and it’ll be as good as the plaste
Thank you
Rich
My question with foam is how to install undermount turnout motors. I’ve seen layouts with traditional wood support for the track and foam scenery behind it but others used foam as the base for the track. Atlas undermounts don’t have a long enough pin for use with foam board. I assume whatever turnout motors you use has to be mounted in some fashion to the wood benchwork. What are the methods used by foam boarders for undermount turnout motors and what brands are used.
My layouts are generally narow (12" to 24" max), so I don’t bother with switch machines. The throw rod spring on my Peco switches is more than sufficient and accesable. In the rare case where a switch machine MIGHT be necessary, I’d just screw it to the 1/4" plywood that I use as an underlayment to the foam. Some foam modelers who don’t use any plywood under the foam just glue a Torotise switch machine to a pad of 1/8" Msonite, and glue that to the underside of the foam. I’ve seen foam layouts with Torotii that have been glues in place for 8-10 years without any problems, and they see heavy use.
Um, what you’re saying is all fine and good but I think you’re ignoring two things:
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There is no right or wrong in this hobby. No need to be a technique-nazi. If it works for you, good. But other methods work for others for various reasons.
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Not everyone has cheap access to extruded styrofoam. Where I live, it’s expensive and hard to find. Home Depot here doesn’t stock it, and gives you a funny look when you ask for it. Only two places in a 50-mile radius sell it for the general public. I can only afford it for my layout base (1" foam resting on plywood). I can afford the oft-looked down white foam for cheap, so I’ll be using that for mountain contours and covering that with hardshell. Hence, the WS method without WS earning a cent - I can get twice the amount of white from from Home Depot than I can get with WS foam (well I did buy the incline starters, but that’s another story). If you want me to go all-extruded foam, then buy me some, dangit. Thank you very much.
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Health reasons. I keep my layout in my room, I don’t want hot wire foam fumes filling the space where I sleep. Not everyone has a garage or basement.
I use light weight spackling. It’s easy to work with and sand. It has approximately the same weight density as foam.
You can cut a hole or area in the foam for the Atlas undermount, run wiring up from the bottom of the foam, set your switch machine down in place, and cut a small piece of foam(from scrap) to set in place on top of it.
Works great, just leave enough room for the arm to stick up through.
Although I’ve got mostly Atlas above-board machines myself, I hate the way they look and I now generally buy Peco for new installations. The Peco switch machines mount directly to the bottom of the turnout, so I cut a hole through the foam (to give me ventilation and easy wiring, and, heaven forbid, a possible removal hole if the machine should ever fail.) For now, I’m making covers for my Atlas machines out of plaster cloth and putting scenery over them.
And MR just ran a small blurb on using heavy duty hook and loop tape, otherwise known as Velcro, to hang motors under a foam deck. Apparently the author had success and it makes it a lot easier if you need to change out a switch machine.
I use Pecos (with the built in spring) myself, so no need to mount or hide anything.
In a word “Sculptamold”. It is lightweight, has a long working time, is easily worked with a palette knife or small trowel or even your fingers, and does not shrink when dry which is just the ticket for cracks and gaps in extruded styrofoam. I used it to fill a gap between a foam hill and a Hydrocal tunnel portal and was very pleased with the results.
Rich, sometimes I just wait till I do my scenery and cover it with whatever I am doing. Plaster cloth, plaster itself, ballast, fill it in with tissue and then paint it over. Whatever my scenery is, that is my seam cover upper. 
Hope that helps:)
Jecorbett, Hi! I asked the same question earlier this week and got some great answers. Lot’s of different approaches. Look back at the index of Forum topics for “Mounting Under Foam Switch Machines” and you’ll see the thread. Or, search on my name. Abbie
I’m a believer in Sculptamold, too. Great stuff, easy to use. I’ve also used plaster cloth.
Both on foam, and since I used L-girder construction, I guess I’m doing everything wrong…
For switch machine mounting, my construction technique makes it pretty straight-forward. Below the foam, I have a layer of Home Depots el cheapo paneling. It’s screwed to the l-girders and gives it extremely strong structural integrity. Switch machines can mount directly to the paneling below.
For pics, see http://www.ironpeng.com/nscalelayout/nscalemain.html
Mike Tennent