The Right (foam) Stuff

[HAZMAT9]

I take it that here in the west (Phoenix to be exact) we have different foam boards as compared to the South or East. The only foam I can purchase here at Lowes or Home Depot is described as the following: "Insulfoam
R-Tech Expanded Polystyrene R-2.9." This stuff I believe has a "pink" backing contrary to the "blue" that everyone mentions. Any ideas if this stuff is okay to use for scenery especially cutting into w/ a wire foam cutter? Thanks, Steve [:)]

[nfmisso]

Steve;

You want EXTRUDED not Expanded for structure. For blocks to support scenery, expanded is okay. There is no chemical difference between the two, so no problems with the hot wire.

http://www.premier-industries.com/insulfoam.cfm?topic=eps

Styrofoam (expanded)- This is the product most people think of when they hear "Styrofoam". It is white in color and comprised of thousands of individual "beads" which are pressed together. The most common use is as a cushioning material in shipping and packaging. Although it is not intended for use as an insulation, it frequently is. Most people have seen cheap coolers and ice chests made from it. As an insulation, expanded Styrofoam has many qualities which count against it. At R 3.84 per inch, the product is simply not a very good insulator. Secondly, it is very hygroscopicity (absorbs and holds moisture). This tendency to get, and stay wet, makes it something to definitely avoid when looking at ice box insulation.

Styrofoam Square Edge (extruded) - This product is often called "blueboard" due to its light blue color. In spite of its relatively modest "R" value (4.92 per inch), Styrofoam SM is our overwhelming recommendation for foam ice box insulation in marine applications. Unlike its expanded cousin (above)and virtually all other foam insulation, Styrofoam "Square Edge" is completely impervious to moisture. This is a huge plus. While many other foams start out as better insulators, they inevitably suffer significant decline as they absorb moisture from the surrounding air. This is not the case with Styrofoam SP. Another benefit of its hydrophobic nature is that no "air gap" is required when installing it. This means that more insulation can be packed into a smaller space. If is available in many thicknesses and two sheet sizes.

http://www.glacierbay.com/dowtest.asp

Some Extruded foam boards are pink. The stuff I get at Menard's here is pink. I think it is from Owens-Corning rather than Dow.

[selector]

Steve, up here in the chilly barrens, the stuff we get is called "Styro-span", and it is blue, and made by Dow Chem. I do not recall other names as I have not purchased the other brands. As Nigel explained, extruded is a specific product and used extensively in the north to line outer walls. When you cut it, it is seemingly solid and leaves a nice, flush and clean face. In fact, you can deeply score it along a line and fracture it like glass.

I have no knowledge of the 'expanded' stuff, but if it looks like little beads of foam pressed together, you are almost better off doing without. If the expanded stuff cuts nicely and leaves a firm, trim edge and face, then I don't see why you shouldn't use it. If it crumbles and pills as you cut, run away!

[HAZMAT9]

On this stuff, the foam comes in 4X8 sheets and is specifically for attic insulation. Unfortunately I can't find any of the Dow foam products here in Phoenix. I know what you're talking about in terms of beads versus more of a sponge texture to the foam. I believe the stuff here in sheets is kinda like the beads, the reason why I wanted to confirm what to use. Anyone in the Phoenix area have ideas on where to get this stuff (Dow) or something that'll work without asphyxiating me when I use the hot wire? Thanks!

[rayhippard]

HAZMAT9,

Have you asked the stores to " SPECIAL ORDER " the extruded foam for you ?
You may have to talk to the store manager. Both these big box stores have extruded
foam in other parts of the country. You may also have to pay extra shipping costs if
it has to come from a warehouse farther away then their regular one.
I hope this helps.

Ray ------ Great Northern fan.

[jacon12]

Steve, I found the extruded foam.. the kind you want, at a little industrial supply place out near the small airport we have. The folks at Lowes and Home Depot had no idea what the stuff was.
Call around to the smaller businesses in your area, and I'll bet one of them have it. Look in the yellow pages under Insulation or Insulation Contractors. One of them will know what you're talking about and where to get it in your area. I live in hot humid Georgia and a dealer had it here, so maybe you do too.
Jarrell

[HAZMAT9]

Fantastic, I'll call around and see who might carry it. We have plenty of AC places around that do insulation work and carry products, I should be able to find it somewhere. Thanks! Steve

[Anonymous]

You gentlemen said extruded would be what to use for support, correct? If I wanted to use this as the base for a layout (i.e. to attach track to, albeit with roadbed between the insulation and the track), does it maintain rigidity? Just curious if this would be a good material to use as a lightweight base.
Thanks!
j

[nfmisso]

QUOTE: Originally posted by madrize

You gentlemen said extruded would be what to use for support, correct? If I wanted to use this as the base for a layout (i.e. to attach track to, albeit with roadbed between the insulation and the track), does it maintain rigidity? Just curious if this would be a good material to use as a lightweight base.
Thanks!
j

2" thick extruded foam is fine for a layout. If you glue it onto a sheet of very thin plywood or similar, a 4 x 8 will be fine on a pair of saw horses or similar. The plywood is to spread the load out. You can walk on a sheet on the floor without making a dent.

[HAZMAT9]

You can also build a "cradle" for the foam kinda like a bed frame to hold the foam w/ some rigidity, or like Nigel suggested lay it on top of plywood for further support. My plywood is rather thick at 5/8" so I plan to cover the entire layout w/ 1/2" or so foam since inserting things such as trees...etc is much easier, plus I have lots of elevation using a cookie-cutter design. Steve

[selector]

HAZMAT, I urge to you go with 1" foam. It will afford you much better purchase for your tree trunks, as well as some depth for modeling water courses, dugouts, depressions, a slight descending grade toward an overpass, etc. That extra 1/2" will certainly cost more, but I think you will find it useful.

J, HAZMAT has it exactly right. Although I have never used 2" foam, many have and report that it is very rigid. So, if you treat it like an ultra firm mattress, and build a frame around it, with legs and maybe a couple of 1X2 joists under it transversely, you will have a very sturdy layout. If you will necessarily have to climb up onto the surface at times, particularly during construction, you will need to double up on the joists for safety.

Keep a small piece of plywood handy to kneel and sit on while you are up there because the foam will dent and gouge....hammers and tools are especially bad for gouging.

Welcome, as it seems you might be new. We hope to see your progress if you can submit pix from time-to-time.

[HAZMAT9]

I guess either way, the 1" foam would be good for depressions, valleys..etc although all my depressions and stuff are in place using the cookie-cutter method, but your idea of the 1" for the tree trunks does make sense, probably would work out just as well. Thanks for the info, now just to find the foam will be the biggest obstacle. Steve

[eridani]

Anyone on the forum in Ontario.
Like an earlier post I asked at my local Home Depot and they knew nothing about it.

I also checked out some Ont building supply websites and found that it appears that fire regulations say that the foam cannot be open to the air--in its intended use it has to be covered with dry wall or plywood etc. Has anyone run

So any suggestions how I can get the foam in the Toronto area?

thanks

RR

[HAZMAT9]

That's interesting regarding fire regulations, anyone else ever heard of that? Steve

[selector]

I'm not sure I understand your question, RR. It might very well be that ON building codes dictate that styro-span and related products are not to be left uncovered if used in the construction of a building space inhabited, or used by, people. It would be due to outgassing and toxicity during fires.

But I don't get what you are referring to about Home Depot.

[eridani]

An earlier post in this thread in said:

"The folks at Lowes and Home Depot had no idea what the stuff was."

I also asked at my local Home Depot in Toronto and got blank stares--perhaps I didn't speak to the right person.

That's when I checked on the web and the only one I found was from a wholesaler who mentoned the fire regs.

I am still checking around, to see what I can find in the Toronto area.

RR

[Anonymous]

[:D]I too have made the guest for the extruded Blue Foam for my Sante Fe,in progress, in Tempe Az. Well good news oh ye of warm(hot),109 F today.In Tempe Az on broadway rd,Tempe Sales,412 W Broadway Rd,480-967-4811.Located 1 block west of Mill Ave,across the SP tracks on the north side of Broadway. 2",4x8 sheets @ about 24.00 dollars per sheet.The folks are good people,open until 6pm and saturdays. I hope this helps .Long Live the War-Bonnet.Bye for now

[HAZMAT9]

Hey thanks Mcjcne for the tip on where to get the foam in Tempe. I'll shoot over there on my way home from work! Thanks, Steve

[orsonroy]

QUOTE: Originally posted by eridani


I also checked out some Ont building supply websites and found that it appears that fire regulations say that the foam cannot be open to the air--in its intended use it has to be covered with dry wall or plywood etc. Has anyone run

RR

We have the same building codes here in the states...for CONSTRUCTION purposes. A layout isn't considered part of the house, no more than furniture or even wall-mounted bookshelves. That it's not available from Home Depot is very strange...

[chrismay]

Hey, Ontario here. If you go into any hardware store in Ontario, or anywhere in Canada and ask for pink or blue insulation foam sheets they will know what you are talking about and if they don't then they won't be in business for long.

This stuff is pretty well a standard in building new homes in most of Canada because of it's durability and ease of install compared with pink fiberglass insulation.

Perhaps they just didn't understand what you were looking for.

[eridani]

An update.
Actually my local Home Depot does have lots of the foam....
I just apparently asked the wrong person.
Last weekend I asked the associate in the plywood/drywall dept. which was inside the store.....a perfectly logical place in my view to ask. He didn't know

Today I asked at the customer service desk and was told it was in the outside lumber yard....where it was.....

On to the next step.....

[chrismay]

I kinda figured that you would be able to find it without a problem. I still find it hard to fathom that anyone working in a Home Depot would not know what you were talking about.

[northern_blues]

eridani (rr)

I'm in the GTA , up Yonge St. from you.

I bought the 2" pink extruded foam to use as a layout base from Home Depot in Aurora. The foam sits on 1" X 3" joists and is a great way to go.

It's very strong at 2" thick and no plywood is required at all.

Don't have to worry about seasonal expansion and contraction due to humidity either.

Dave

[randyaj]

I have to give a differing opinion on the foam. On my HOn3 layout and my new layout that I am in the process of adding scenery to, a have used the white expanded foam. Yes it makes a big mess, but I love the texture of the foam. It cuts very easy, I use a hacksaw blade and a *** file, halfmoon file and sureforn to form the terrian that I want and then cover it with plaster cloth. In a cut I can leave the saw marks in the foam modeling the cuts the crews made through the hill, and in the plains I can gently file it into smooth rolling hills. And the cost makes it even better at half price of the "other" foam. I paid 9.97 for 2" foam a Home Depot. The possibliities are endless Steve.
Randy Johnson

[Bikerdad]

Expanded Polystyrene, aka "styrofoam", is the same stuff that "styrofoam" coffee cups and beer coolers are made from. (And Life-Like "tunnels"). Extruded Polystyrene, aka Styrofoam, is the blue stuff made by Dow Chemical. Styrofoam is a trademark, similar to Xerox, which has taken on a meaning beyond the specific product of a specific manufacturer.

Extruded polystyrene [EPS(t)] is also available from Owen's Corning (pink), and others. The widest variety can be found from a supplier in Burbank, CA. They supply blue, tan, pink, green, etc EPS(t) to signmakers, construction companies, refrigeration contractors, artists, and theatrical set makers. Wanna carve a 10' tall tiki statue? Call them... (Remember those boulders in Star Trek?) Small quantities can be found at any floral shop or even Wal-Mart, where it is available in the craft section for floral arranging and crafts.

For those of us in the Sunbelt, the best source of EPS(t) will be a commercial refrigeration contractor, i.e., the folks who supply and install walk-in freezers and refrigerators. Most simple A/C contractors won't have much, if any, experience with the stuff. EPS(t) is generally available from such suppliers in thicknesses ranging from 1/2" to 4", with a wide array of structural properties, including hardnesses that will allow you to walk across it in high heels without leaving a dent.

Whether expanded or extruded, all polystyrenes are flammable and the moderately toxic. They are nothing more than "foamed" styrene plastics, so simply melt one of your boxcars to get an idea.

[oleirish]

QUOTE: Originally posted by nfmisso

Steve;

You want EXTRUDED not Expanded for structure. For blocks to support scenery, expanded is okay. There is no chemical difference between the two, so no problems with the hot wire.

http://www.premier-industries.com/insulfoam.cfm?topic=eps

Styrofoam (expanded)- This is the product most people think of when they hear "Styrofoam". It is white in color and comprised of thousands of individual "beads" which are pressed together. The most common use is as a cushioning material in shipping and packaging. Although it is not intended for use as an insulation, it frequently is. Most people have seen cheap coolers and ice chests made from it. As an insulation, expanded Styrofoam has many qualities which count against it. At R 3.84 per inch, the product is simply not a very good insulator. Secondly, it is very hygroscopicity (absorbs and holds moisture). This tendency to get, and stay wet, makes it something to definitely avoid when looking at ice box insulation.

Styrofoam Square Edge (extruded) - This product is often called "blueboard" due to its light blue color. In spite of its relatively modest "R" value (4.92 per inch), Styrofoam SM is our overwhelming recommendation for foam ice box insulation in marine applications. Unlike its expanded cousin (above)and virtually all other foam insulation, Styrofoam "Square Edge" is completely impervious to moisture. This is a huge plus. While many other foams start out as better insulators, they inevitably suffer significant decline as they absorb moisture from the surrounding air. This is not the case with Styrofoam SP. Another benefit of its hydrophobic nature is that no "air gap" is required when installing it. This means that more insulation can be packed into a smaller space. If is available in many thicknesses and two sheet sizes.

http://www.glacierbay.com/dowtest.asp

Some Extruded foam boards are pink. The stuff I get at Menard's here is pink. I think it is from Owens-Corning rather than Dow.

[:)]Last time I used foam It was some white stuff,corse with a backing on it that was a bear to remove!!!!!![:(!]The EXTRUDED you talk about seams what everyone is useing?do'es it have a backing that is hard to get off?
JIM