Owens Foamular 150 v. DOW Wallmate v. white R-Tech Faom


Mogul2-6-0

Rookie Switchman
Extruded Polystyrene Foam: Owens Foamular 150 v. DOW Wallmate v. white R-Tech

So I'm foaming at the mouth. (another foam thread) been searching, it can be confusing.
Got some of the white foam at Home Depot.
Its the only thing I can find so far.
Seems usable for my practice diorama, but crumbles easily, kinda chunky surface too?
Searching for the good stuff, if not for this diorama for the somday layout plan.
So far seems like Owens Corning Insular 150 "pink" in 1" is the best choice?
Seems the 150 or 250, either is OK? Or what about R 2,3 ,7 10 etc I'm guesing the higher the R number the denser the foam? Maybe better for details but harder to cut.
I'll just be happy to find any of the pink stuff :D (ha ha that sounds funny LOL)
The blue DOW stuff seems comparable but has tounge and grove edges I dont think I want.
The white stuff is "expanded" polystyrene not 'extruded', its a big difference in density.

Anyone know were I can find some pink stuff in San Diego county?
I think I may have found a place in Riverside county.
Seems this stuff isnt so popular her in Southern Cal. no basements.
This is why I ask, if I'm going do all this searching and driving I might as well get the best stuff I can but also dont want to break the bank either.
Another question:
Once I shape and glue the foam should I paint it or cover it with plaster of Paris or Hydrocal or mold a scene or...
I'll start "My first practice experimental learning diorama" thread once I download/upload some more pics.
References:
http://insulation.owenscorning.com/homeowners/insulation-products/foamular-150.aspx
http://building.dow.com/na/en/products/insulation/wallmate.htm
http://www.homeconstructionimprovement.com/foam-board-insulation-values/
 
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Richard,

The white stuff is expanded polystyrene, commonly called bead board. This is what most people incorrectly call styrofoam. You want the pink or blue extruded styrofoam. The bead board is almost worthless for modeling, since it has very little strength and you've already seen what happens when you cut it.

The Dow and Owens-Corning brands are essentially the same. Don't worry about the tongue and grove. That can easily be cut off and squared up. It is harder to find the styrofoam in southern Califronia but it can be ordered. A real construction supply store, not a big box store like Home Depot, is the most likely to have it, or be able to order it for you. We have some other members in your area that have gotten it and may be able to supply you with some leads.

You didn't mention what scale you are in. For N scale, 1" is fine. For HO, 2" is better, since you have some more depth to use for things like creeks, lakes, and ditches. You can also laminate two 1" pieces together using cheap adhesive latex caulk.

There are any number of ways to scenic the foam once it's in place. Some people use scupltamold or patching plaster to fill in the seems after shaping the foam and just apply paint, washes, and ground cover right to the foam. Others use plaster of paris, hydrocal, or patching plaster to cover most of the foam. The best way to see what works best for you is to do a couple of test dioramas and use the different methods on each. I carved and shaped the foam, filled in the seams, and then did all the scenery work on the foam. There's no "right" way, just whatever works best and looks the best to you.
 
Jim,

Again thanks. Great info. I'm working in HO.
Maybe I'll try and call the 2 big clubs in San Diego and ask them where to go.
I think I'll try and track down some pink stuff before I glue the white board together. None at Home Depot or Lowes, cant even figure out how to order it online from them, have to look elsewhere.
I'll still carve on the white stuff for practice.
Yeh I figure I can create a 2" base as you metioned before by glueing 2 1" boards together. Can I use Elmers "glue all"? I bought some. Is this the whte glue people are talking about? Maybe I'll get some adhesive latex stuff you metioned. I bought some liquid nails too, for plastic, foam etc? too expensive for large areas?
I like the idea of applying a wash or paint and then grass, scenery right to the foam. Also using something like plaster for seams, fills, build ups etc. I'll be doing some experimentation for sure, thats one reason I'm doing the diorama. Its way fun too.
Oh yeh my wife was just on the phone and mentioned all the little white pieces of foam all over the garage. LOL

Thanks,
Richard
 
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I used some of the white on my layout. I put about 5 coats of latex paint on it trying to cover the beads. Didn't work. But, most people visiting don't notice the beadboard look.
I had used all of my green & pink on my previous layout & glued it together w/liquid nails. Couldn't reuse that part. The foam board that I glued together w/Elmers glue I could get apart. The thing w/Elmers is; It takes about 3 or 4 days for it to dry completely. I also used 6 & 8 penny nails to hold it together till it dried. If you have a lot of steel weights like I do, you can use those to lay on top to hold it together.
I used a 4" electric hand grinder to form my pink & geen mountains. It makes a lot of very fine dust. You need a good respirator(not a dust mask), goggles, ear plugs & an apron & wear old clothes. You think I'm kidding. Try to breathe normally after carving on foam. can't if you don't wear the gear. same thing w/Celotex ceiling tiles.
 
the beadboard is suitable for rocky cliffs, otherwise you'll need to cover it with something life Sculptamold, plaster or whatever. But if you cut it with a hot knife the texture is pretty smooth. The fumes are noxious however.
 
Celotex ceiling tiles work real nice for mountains, hills, etc., but it's harder on your breathing than foam. It's a lot easier to use & glues together w/Elmers or a hot melt glue gun. I've built some beautiful mountains out of it. It looks like real rocks when it's finished. But, foam is thicker. It's real cheap if you go to your local hardware store & buy their damaged pieces. It comes in 2ft by 4ft sheets. If you use it the non fireproof kind is better. You don't have to use any caulk or sheetrock mud or plaster to fill the cracks. The layout before this one had a mountain 12ft. long by 4ft wide & 18" high & all my visitors thought it was real stone.
 
Richard, you can use white glue, yellow carpenter's glue, Liquid Nails for Projects, and adhesive latex caulk. The white glue takes the longest to dry and the Liquid Nails takes the least amount of time and is really strong. Latex caulk is about in the middle in terms of drying time and strength and is the cheapest for large areas like foam boards. I prefer latex caulkbec ause I'm cheap. :)
 
If you want to cover the 'beads' in beadboard, get a bucket of drywall topping compound. I used to have leftover stuff from doing drywall work. It would get too lumpy to use on drywall so I tried some for scenery. Stir in enough water that it gets the consistency of thick paint. Apply with a wide paint brush. You can add pigment to the mix or just paint it when it dries. 2 or 3 coats will cover and fill most anything.

It cleans up with water and is relatively cheap to use.
 
I bought a piece of the white expanded beadboard and messed with it. I was able to cut it pretty easily with a fine toothed hacksaw blade. I'd consider using it to build up contours or if I absolutely could not find extruded foam, but the extruded (pink, blue) foam is far superior in my opinion.

I laminate layers of 1/2-inch extruded foam together with Aileen's Tacky Glue. I can only find foam in 4X8 sheets here, which don't fit into my car. Cutting 2-inch foam sheets in half in the HoPo parking lot has proven to be a pain but the 1/2-inch sheets cut easily with a sharp utility knife and a drywall square.
 
Sweet I just found a shop near my house with the DOW blue boards in 1 inch "square edge!!!" in 2 foot by 8 foot sheets at $11.39 ea.
He has 150 of em, should be enough for good sized layout LOL
FYI: Mac Arther Co, 2101 Haffley Ave, National City (619) 399-3426
Thanks again to all for the great feedback. I'll let you all know how it goes.
Funny people use this stuff for surfbord cores and RC plane/glider wings also.
 
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