blue foam sheets

I'm planning on building a N scale railroad on a sheet of 4x8 plywood. I keep reading about the blue foam sheets but don't understand the advantages.
Could someone enlighten me on the pros and cons of using the foam?
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The Stare wrote:

-light weight -easy to carve/sculpt/cut -fairly rigid -available in several thicknesses (I commonly see 1/2 up to 2 inch, and have occasionally seen 4 inch) -fairly inexpensive
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Here's some cons: -Doesn't hold track nails well, so glue is required. -Cutting can be messy, or very smelly. (Depending on the method used.) -Easily broken, so portable layouts require additional supports. -Plaster doesn't stick as well to foam as it does wood. (I get around this by gluing cheese cloth to the foam and then adding my plaster.) -Sensitive to glues and paints.
Pro: -Takes acrylic paints well (especially the Apple Barrel colors that are available for around $0.44 a 4 oz bottle.
A couple other thoughts, not Pros or Cons: -A hot wire foam cutter helps cut through the material, and you can make one for next to nothing. (See the directions posted at: http://groups.yahoo.com/group/thehoscalemodelrailroadclub/message/1913 ) -You don't have to use foam for your track bed. If you do this, you can use pine boards to spike your track down and still have the foam for scenery.
Puckdropper
--
If you're quiet, your teeth never touch your ankles.

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"Puckdropper" <puckdropper(at)yahoo(dot)com> wrote in message

There's been debates on rec.models.railroad in the past regarding flammability and noxious fumes if it catches on fire. The spirited debates on the topic was an indication that the jury is still out on how serious that con might or might not be. But the individual modeler should at least consider that aspect. You can read more by searching the rec.models.railroad archives at http://groups.google.com/group/rec.models.railroad /. ____ Mark Mathu
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Mark Mathu ( snipped-for-privacy@mathu.com) said...

I have used this in the past for small layouts. The flammability of foam is a concern, made more obvious to me when we built our home a few years ago and used ICF (Insulated Concrete Forms) for the foundation. Our building code (and probably most others) require that ALL foam insulation be covered. Outside, that meant that the stucco finish on the house had to go down to the grade line. Inside, that meant that ALL outside basement walls had to be drywalled.
With that in mind, how many model railroaders plan for a field of blue or pink? By the time scenery is finished, most of it is covered by plaster or a similar coating. Even on flat areas, I usually used a thin "icing" of plaster (rough up the foam surface a bit, and it holds quite well). The underside is another issue, though. In my case, I was building a small portable layout, so I laminated the foam to a half-inch sheet of particle board, and the edges had counter laminate applied as a finish.
--
Calvin Henry-Cotnam
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*trim and snip*

What I meant by that is that replacing the plywood with foam is generally a bad idea for a portable layout. It might work with a permanent one, but portable ones need that extra support. (It's not easy to say everything you want to say when doing a "cons" list.)
*snip and trim*

Agreed. I'd also like to recommend using a CAD program like XtrakCad that allows you to run virtual trains before you start building, to get a feel for how your layout will operate.
Puckdropper
--
If you're quiet, your teeth never touch your ankles.

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Puckdropper <puckdropper(at)yahoo(dot)com> wrote:
[...]

Like anything else in life, there are plenty of exceptions. I agree that 3 feet is a practical limit for any layout up against a wall. In this case though, foam construction makes it a lot easier to pick up the layout and move it to the center of a room so that you can work on all sides.
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Puckdropper wrote:

(( ( (((SNORT ))) ) ))
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MangroveRoot wrote:

I thee we have man with a lithp in our midtht.
Hah!
--
Wolf Kirchmeir

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On Tue, 13 Jan 2009 16:23:41 -0500, Wolf Kirchmeir wrote:

What have you got against Lots of Insane Silly Parentheses?
--
Steve

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Steve Caple wrote:

Nussing at all.
--
Wolf Kirchmeir

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Wolf Kirchmeir wrote:

(GRANT LORD US MERCY), what *have* I done? (or, for the traditionalists 'umungous, GRANT (LORD US MERCY))
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MangroveRoot wrote:

Shirley you mean (GRANT (LORD (US (MERCY))))
And that's the end of it for me. ;-)
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How boring...
(lambda (MERCY)     (cond ((GRANT-P 'LORD 'US) MERCY)      (t nil)     ))

--
Robert Heller -- 978-544-6933
Deepwoods Software -- Download the Model Railroad System
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some guy wrote:

Seconded. It's a wonderful material! It's very quick, too -- see last paragraph below. BTW, there's also pink foam, which is softer and easier to work with, and black, with is denser and breaks in patterns that are very rock like. Do not use white bead-board!
I've found the easiest way to cut the foam is with a paring knife, or a bread knife for thicker sheets. Mark the desired contour, insert the knife at an angle, working your way along the contour two or three times until the piece falls apart. To make rock faces, slopes, etc, insert the knife at an angle and twist. Keep the knife sharp. Don't use a saw, they make too much dust, and don't use heated wire cutters, the fumes are toxic. There is very little waste - all the scraps you cut off can be used to build up scenery.
For track, mark out the centre lines, and glue cork in place. Use water-based latex glue, the thin kind that comes in pint cans. You can pin the track to the cork temporarily until you've ballasted it - the glued ballast will hold the track in place, and then some.
For scenic cover, begin by using plaster impregnated cloth. Buy the cheapest available (usually at art supply stores.) Cut into approximately 4x6 rectangles, dip into water, and apply. Very clean and fast. Add rock castings etc as desired. After the plaster has dried, paint all over with cheap latex paint in a sandy or rock coloured shade, paint with washes of acrylic craft paints to get variety in rock colours and earth colour under "grass", and apply ground cover etc as usual.
If the layout is to be portable, make a frame of 1x2 with crosspieces at about 12-16" centres, glue a sheet of 1/4" ply onto it (the cheapest floor underlay is more than adequate), and glue a 1" foam sheet onto it. Use a water-based latex glue. I've used construction glue in tubes, but find it's too thick, and have looked for and found thin latex adhesive in cans. I apply this with Popsicle sticks, or spatulas made of scrap wood. Apply to both surfaces, wait about 5 minutes, and place foam sheet. At 5 minutes, the glue is still workable, so you can make minor adjustments, but locate the sheet as accurately as possible. Place weights on top, and let set overnight. this will be the base or zero level for the layout.
To glue pieces of foam to build up scenery, use the latex glue as a contact cement. Apply, wait 15-30 minutes, and stick together. The bond is instant, so test fit the pieces before you glue them. I also add a couple of register marks when test fitting. to ensure the pieces go in place as planned.
I built a 32"x48" N scale demo layout for a trade show in 7 days, including one day waiting for the plaster cloth to dry, and working less than fours a day! It was incomplete, which was actually an advantage, as it showed visitors the stages of building. Adapted from "Oyster Bay" in _101 Track Plans_, it has a tunnel, a bridge, a bay, a passing track, and two spurs. I'm puttering away at it.
Have fun!
--
wolf k.

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Wolf Kirchmeir wrote:

There's also yellow foam, which comes sandwiched between sheets of aluminized paper. It's sold under the name R-Max IIRC. I've never seen any discussion of anybody trying to use it though.
--

Rick Jones
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some guy (1@2.3) said...

Here's a pro that I rarely see others mention:
Running wiring can be done on the surface: just score a cut where you want it to go and use a small slotted screwdriver to stuff the wire(s) into the slit.
--
Calvin Henry-Cotnam
"Unusual or extreme reactions to events caused by negligence
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wrote:

One *minor* nit: the foam comes in (at least) two colors:
Blue is made by Dow (and others). Pink is made by Owens Corning -- all of Owens Corning's insulation products are colored pink -- their trademark / mascot / spokes cartoon (?) is the Pink Panther.
The Pink and Blue foam is the same material: building insulation foam, commonly used to insulate foundations and/or poured concrete building walls. Getting the stuff can be problematical in warmer climate areas (eg Southern United States, etc.). It is commonly available at building supply places (Home Depot, Lowes, local lumber yards, etc.) in colder climate areas (eg New England).

--
Robert Heller -- Get the Deepwoods Software FireFox Toolbar!
Deepwoods Software -- Linux Installation and Administration
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Robert Heller wrote:
[...]

One thing I've never understood is that people think you need insulation only to keep heat _in_. It's just as good at keeping heat _out_. Air-conditioned buildings need insulation just as much as heated ones, if not more. I know the first thing I'd do if I ever move to southern Texas (where one of my daughters lives) is insulate whatever house I buy, add a heat exchanger / ventilator, and a ground effect heat pump.
HTH those of you who live in those hot places. ;-)
--
wolf k.

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Wolf Kirchmeir wrote:

Considering the fact that more energy is expended (1st) world wide cooling than heating, that has to be a realistic outlook.
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