pink foam combustible. need I worry?

[Anonymous]

Hey guys and gals, brand new here and relatively new to the hobby(tried it once when I was younger but got distracted). So now that I'm attempting my first layout(n scale 3'X6') I've read many people use pink insulation foam as a base. I went and bought some and attached it to my table and now I realize that it says 'combustible' on it. Is this something I should worry about? Did I get the wrong kind?

I know it's a newb question but I just thought I should make sure before I start wiring/laying track.

Thanks
JASON

[Bergie]

Welcome back to the hobby and welcome to our forum.

You'll be fine with that pink foam. I've used it and it's perfectly stable. I'm not sure what would cause it to combust.

Correct me if I'm wrong, but isn't wood technically combustable too?

Bergie

[KenK]

So....pink foam is combustible.......just like Homasote.......and........wood?

[tstage]

Jason,

Welcome to the hobby!!! [:)]

I use extruded foam insulation myself and love the stuff! [:D] It's great for repeatedly trying out your layout design ideas. Sectional track holds very well to it with just a rail spike pushed through the hole in the ties. If you don't like what you see, you can always pull the spike up and try another idea.

Let me add that holdling down track in this fashion really should be viewed as "short-term" rather than "long-term". Once you've decided on your final layout design, you should really lay it down more permanently. Having said that, I'm well into my 4th month of my current "temporary" layout idea and the track is holding to the foam VERY nicely. [:)]

As far as combustibility is concerned, there's no need to worry. Either wood or extruded foam insulation are combustible. The main difference is that burning foam gives off some nasty chemicals that wood wouldn't. In either case - whether wood or foam - if your layout is going up in flames, it's best you not be near it when it does.

Jason, I would be negligent if I forgot to add one last important point. Whenver you do get around to making your layout design more "permanent", you do have to be careful what you do use to glue down or paint your foam with. Your paint and adhesives need to be a NON-SOLVENT (i.e. latex) based product. Check the label carefully. Solvents will melt the foam fairly quickly and turn your beautiful layout into a very gooey mess. [:(]

Jason, I hope you can join us on a regular basis. Learn as much as you can. I still am...

Tom

[cwclark]

as long as you aren't going to use a blow torch on the layout or plan on burning your house down, the pink foam will be fine. everything burns if it gets hot enough...Chuck

[Anonymous]

I would assume there might be worry that a wiring short or something that gets hot in a small spot might cause a problem. But I would think, in the case of a short the foam would not catch fire but melt back until it is far enough away from the heat source that it would stop on its own. Just like when you use a hot wire to cut and shape it. But I am still new to the hobby (only planning layouts for 15 years. Now finally building one) and have no direct experience with foam.

[DSchmitt]

Actually it turns from a solid to a gas when too much heat is applied, and as tstage says some of the chemicals it gives off when heated can be a problem. It does not actually burn and as soon as the heat source is removed it stops melting. Also be careful with solvent based paints, plastic cements and chemicals like acetone when working around it. I have used acetone, applied with a paint brush, to create depressions in it for creeks and ponds.

It is good practice to have some other material such as a thin plywood under it and on exposed ends and the scenic surfaces covered with plaster cloth or a thin layer of plaster.

I wasn't warching a soldering iron once and put a hole through a piece. The real danger was that if the iron had reached the floor it might have set the carpet on fire.

[dharmon]

QUOTE: Originally posted by cwclark

as long as you aren't going to use a blow torch on the layout or plan on burning your house down, the pink foam will be fine. everything burns if it gets hot enough...Chuck

So unless you are going to wear it to the Tahitian Fire Dance........or have small hobo campfires with actual fires.....it should be okay......anything else, and you'll be needing to leave the house anyway...

[Anonymous]

Experiment time:

Took 1 3"x3"x1" foam.
In an outdoor location, placed it on a flame-resistant surface.
Held a lit match to it.

Results:

Immediately the foam began to melt.
Within seconds, the foam was ignited, burning with a thick black smoke.
Removing the heat source (the lit match) resulted in the foam quickly extinguishing itself.

Conclusion:

On small pieces of foam, there is little concern about combustibility if no other combustible material is available to sustain the foam's ignition.

Remarks:

Large pieces of ignited foam may produce enough heat to maintain ignition without a steady external heat source.

Since foam used in model railroading is usually larger in size than the sample and is seldom isolated from amounts of other combustible material, the possibility of a sustained fire exists.

It appears the extraneous material used in a model railroad, (wood, plastic, etc.) offers more "fuel for the fire" than an equal amount of foam board. The danger of toxic gasses from burning and or melting foam seems to be more of a concern than the burning foam itself. A modeler should look at the combined dangers of toxic gasses from rigid foam board and the other components over that of combustibilityof the layout to judge risk .

Disclaimer: I am not a scientist and do not even play one on the internet.

Wayne


From the US Department of Energy website:
"Foam insulation is relatively hard to ignite but when ignited, it burns readily and emits a dense smoke containing many toxic gases. The combustion characteristics of foam insulation products vary with the combustion temperatures, chemical formulation, and available air.

Because of the dangers described above, foams used for construction require a covering as a fire barrier. One half-inch thick (1.27 cm) gypsum wallboard is one of the most common fire barriers. Some building codes, however, do not require an additional fire barrier for certain metal-faced laminated foam products. Check with your local building code/fire officials, and insurers for specific information on what is permitted in your area."

[orsonroy]

The foam is no more dangerous that the carpeting on your floors, or the cushions on your couches (of course, it's no more safe, either!). Just don't add flame to it, and you'll be fine.

[twhite]

Nah. I'm using it in my garage as a train table base, and the only problem I've had with it is accidentally laying my soldering iron on it. No smoke, no fire, the soldering iron just melted its way through like a knife in a cake. Of course, I have a strange little hole there, but I think I'll disguise it as a well.

[Fergmiester]

Muddy Creek has this one nailed. I use white foam, When I purchased the foam it came with a fire rating but like everything else if given the right conditions any substance will burn.

I have a fire extinguisher in my work shop just in case but more importantly I make sure I leave no ignition sources unattended.

[Anonymous]

Thanks to everyone for both the welcomes and the quick replies. I kinda figured I was being paranoid, but with my complete inexperience with wiring I had to ask to be sure. I'm feeling much better now. Now that it's out of the way I'm finding what is probably one of the biggest hurdles for model railroaders--commiting to a layout! Everytime i think I've settled on one I change my mind. I'm also finding elevation tricky-it's one thing to design some nice track, it's another to figure out how to get them up and down.
Having said all that, that's what I'm liking about the hobby: it's a major learning process.

[tstage]

Jason,

As I mentioned in my earlier post, if you're wrestling with settling on your layout design, then you picked the RIGHT medium to do it with - foam.

Since you have a computer, go to http://www.atlasrr.com and get their RTS (Right Tracks software) download. It uses the Atlas sectional track, turnouts, crossings as a template. It free and worth playing around with.

On the topic of elevation or grade, I haven't personally used it but some of the guys really like the Woodland Scenic risers. They are "tapered" at various grades to get you up to your next elevation (and down) without creating that ackward transition between level and grade. A general rule: If your layout allows, try for a grade of 2% or less.

Hang in there Jason, and learn what you can. Play with as many layout ideas as you can come up with. I was looking at my 4-month old "idea" late last night and thought I might make a few changes in order to incorporate some additional locomotive service capabilities. (That's what's so much fun about this hobby: Learning and trying out your ideas.)

Anyhow, from one newbie to another...

Tom

[ahuffman]

I would like to see a building products or fire safety professional respond to this query. Having seen the results of upholstery foam burning, I think most of the responses take this issue too lightly. As noted earlier, most construction foam is required by building codes to be covered with a fire-resistant material like gypsum board. Given the large volumes of foam being used in some modern layouts, I think there is a real fire safety issue here and would hate to see a family injured or killed by the products of combustion from a hobby room fire.

[tstage]

Hey polizi! Are you out there?!? I just learned from a recent post that Polizi is a fire fighter. It would be good to hear his input on this.

Tom

[ericsp]

Just about everything on a model railroad will burn. Some more easily than others. By the way, I am guessing that foam is probably foamed polystyrene. Many (if not most) plastic trains are made from polystyrene (not foamed).

[Anonymous]

Hi guys sorry took me so long to reply was working at the station. MrClark the pink foam is as it is labeled "combustible" not flammable or explosive so there really is no need to worry that it will just suddenly catch fire and burn everything down. Now this will not preclude something else catching fire and having it then support the cumbustion.

The big thing to remember is fire load (things that burn in an area) lets say our layouts
wood frame construction with a foam top covered in paint and plaster and newspaper and other various hobby materials. most of these items are combustible meaning they need a direct scource of ignition to burn. As you can tell from other posters heat alone will not cause this reaction.

Now paint fumes and glue fumes on the other hand are a different story as these are Flammable and or Explosive. but thats another show.

I would make sure you have no open direct flame scource nearby the layout and if your worried about wiring causing this insulate your slpces and connections well as we should all be doing anyway....right guys???


as a last note for those who are working in there basment or garages with a fossil fuel type of heating unit please invest in and install working smoke detectors and a carbon monoxide detector it may save your life and your family....

[Anonymous]

Polizi is right on in his comment, I have been a career firefighter for 28 years, the last 12 as Asst, Chief/Fire Marshal.

The UBC (Uniform Building Code) calls for the foam to be marked combustible when it falls under ceratin conditions. They rate it for flame spread< 25, smoke development <450 and ignition temp 650 deg. Wood's igniton temp is 455 deg. The materail must be tested usually by UL (Underwriters Lab) or FM (Factory Mutual). There are some other testing agencies but these are the most common.

In the 70's or early 80's, UL tested polyurathane foam insulaltion, different than the extruded polystyrene, and found it safe. Only trouble they tested it when it was laying flat. When it was used vertically on a wall it burnt like crazy.

Bottom line, the extruded polystyrene is safe, I use it myself and hvae no great concerns about it's use.

[tstage]

Thanks, polizi and B A and P! We also greatly appreciate the job and the work that you both do. [:0]

Tom

[Anonymous]

Thanks again guys, especially our resident experts. A little reassurance goes a long way!

tstage, thanks for the advice on layouts, I tried that atlas program you mentioned as well as one other, pretty good to see what fits. So many layouts so little square footage-I think I may have commitment issues! :)

Thanks again to everyone
Jason