Blue Extruded Poly Styrene vs. the Pink Stuff

[HarryHotspur]

Matt - Just a suggestion, but what about you and your Dad getting a scrap piece of foam and holding it over a candle flame? That way, he can see it doesn't burn. I suppose the melting foam might be a concern, but it can't be as bad as flaming plywood.

Harry

[TheK4Kid]

Hi Matt, I can personally tell you it simply doesn't burn!!!
 CASE IN POINT!!
 I also build and fly radio-control sailplanes which often use pink and or blue or white foam as cores for the wings, then sheeted with balsawood or fiberglass.
Maybe 15 years ago, a friend of mine accidentally landed his sailplane with foam core wings on a set of HIGH TENSION POWER LINES!!!
 The wings were reinforeced with CARBON FIBER material in the wingspars and the carbon fiber was on the outside surface of the spar.
Now considering these power lines were carrying about at least 30 THOUSAND VOLTS, when the wing slid to a stop, the power lines ARCED and BLEW a transformer on a pole a short distance away. BOOOOOOMMMM!!!!!!!!!,
Yet the foam wing simply MELTED and NO part of the sailplane caught fire!
So there you go the ULTIMATE TEST !!!!
As for the electronics on board the aircraft???
No damage whatsoever!!!!

 Ed

[Anonymous]

Well, continuing with my side of things, I got a response from Owens Corning today.

Thank you for contacting Owens Corning. We have no recommendations for using Foamular in model railroads. The maximum service temperature for Foamular is 165 F.

The way I see that is not the combustion temperature, but rather the temperature where it beings to melt.

 

[ARTHILL]

There have been several threads about its use, carving, painting  and use with ground goop. A search should give some. There are also some of us who would be willing to share our experiences again.

[Anonymous]

Is there a site that explains how to use the pink insulation as scenery?  I have only used it for sound deadening under my HO slot car track set-ups.

Mike/Nightshade

[grayfox1119]

MATT: I can understand your dad being concerned, especially if he is not a modeler, as he would more than likely not have any knowledge of it's properties.
May hundreds of modelers are using the pink or the blue insulation foam, including myself, and rest assured there is NO FIRE HAZARD!
I have conducted my own test several years ago just to see what it's flamability was.

[Anonymous]

Thanks, I'm waiting on an e-mail from Owens Corning. Hopefully, they will convince my dad that this stuff is ok.

[PA Belt]

i have white and pink, i like the pin better, easy to clean up

[CP5415]

Is there any difference between the Blue and Pink Extruded Polystyrene? I read on some site, they are VIRTUALLY identical. Virtually Identical doesn't mean identical.

 

The pink is used in girls rooms & the blue is used in boys rooms

Gordon

[ericboone]

Thanks, but what about flammability? Is there any difference between Dow's and Owen Corning's? And will Latex Paint help provide a barrier against any flame, spark or heat. My dad is *cough overly cough* concerned about it "flaring up" in a little fire.

You can also tell him the foam is most commonly used in home construction as insulation and codes would not allow a highly flammable material to be used for that purpose.

[rrinker]

  There are variations in both brands, and it probably is somewhat region-dependent on what type is carried by your local suppliers. The only product sold in the Home Depots around me is Owens-Corning Foamular 250, the pink stuff. A visit to the Ownes-Corning web site shows they also make a pink Foamular 150, which is lighter and less strong, and a Foamular 350, which is heavier and stronger than the 250. A similar visit to the Dow site shows they make the blue stuff both with and without the skin, and with and without the interlocking tabs on the long edge.

                                   --Randy

[91rioja]

The blue I purchased at the local Lowes has a coated plastic thin film over it.  When I ran out and had to go to Home Depot, all of the pink stuff did NOT have the film covering it.  That is the only structural difference I have found.

Chris

[colvinbackshop]

I have used the pink, blue and yellow and have not been able to tell much if any difference between them. As Art stated, the density may be a bit different, but even that seem negligible to me.

The gray stuff, however is something different all together! It's not an expanded bead (the white stuff) but it sure is different then the pink, blue or yellow...seeming to be not as rigid nor as dense.

[TheK4Kid]

Virtually no difference in pink or blue foam.
I also build RC sailplanes and use either in cutting foam core wings.
Both cut about the same. I have a special table I built  for  working with foam and use an outfit called a "Tekoa Feather Cut" foam cutting setup with all of the accessories, so I can cut virtually any shape.
The trick to cutting foam if you want to make let"s say identical parts for making a building is to have good templates made out of mica or aluminum.

I made a building out of foam by first cutting a larger piece of foam to a rectangular shape, then cut it into thinner slices, then cut out winows, doors, etc. Then glued it all together, and added details
Thought about trying a larger building like a Spectrum skyscraper. Cut it out of foam, then add balsa
for sides, then  lay on a "brick"siding type decal of some kind, then add details like windows, etc.

Thought it would be an interesting experiment.

If anyone is interested Tekoa has a website at      www.tekoa.com

 Ed

[dgwinup]

Have no fear, Matt and inform your Dad that both the pink and blue foam, and probably the yellow and green, will NOT support combustion!  These foams melt at very low temperatures and even the residue will not support combustion.

In order for the foam to burn, a source of fire must be present.  Remove the flame and the foam self-extinguishes.  In a few personal instances, the foam melted so fast that it retreated from the flame before it could ignite!  It has to be one of the safer products to use in model railroading.  On the other hand, all wood and plywood products will burn when exposed to a flame, and they will continue to burn after the flame has been removed.

Go with the foam.  It's not only safe and easy to use, it's fun to play with just to see what you can do with it!

Darrell, quiet...for now

[Anonymous]

Thanks, but what about flammability? Is there any difference between Dow's and Owen Corning's? And will Latex Paint help provide a barrier against any flame, spark or heat. My dad is *cough overly cough* concerned about it "flaring up" in a little fire.

[ARTHILL]

No difference between the blue and pink BUT:

There is a difference between different weights in each color. When I buy it I buy the lightest weight. When I get it at a construction sight, I take it all. The green is more dense but still the same stuff. The yellow is still more dense but works, but I have not found much of that yet. The Arizona scene beside the canyon has all four colors in it.

The only real diference seems to be the ease of cutting. The hot wire sure likes the light weight the best.

[MisterBeasley]

Not exactly the same.  One is made by Dow, the other by Owens-Corning.  There may be minor differences in the chemical makeup or air content, but I don't think I've ever read anything about one that wasn't true of the other.  Home Depot carries the pink stuff, so I use the pink stuff.  Art Hill has both in the walls of his canyon, sort of like a lesson in geology where the layers represent different chemical companies.  Art, have you noticed any differences?

[grayfox1119]

Just made by two different companies...the pink is made by Owens Corning. I have used both, no difference for modeling purposes.

[Anonymous]

Is there any difference between the Blue and Pink Extruded Polystyrene? I read on some site, they are VIRTUALLY identical. Virtually Identical doesn't mean identical.