To use foam or not?

[orsonroy]

QUOTE: Originally posted by CBQ_Guy

You've gotten a lot of good advise here, so there's not much I can add except to consider that when foam burns it gives off toxic, make that lethal fumes!

Second, ignore comments concerning Homasote being affected by water and moisture...just ain't so. I was surprised to see that this model railroad urban legend is still around.

Good luck with your layout!

Paul,

sorry to contradict you, but from my own experiences, just the opposite is true. In high school, I worked in a lumber company, and have seen Homasote swell to six times it's normal size due to just humidity. And according to Dow's MSDS safety sheets, as well as independent tests conducted by the University of Oklahoma (both available online) foam is no more dangerous (and no more safe) than burning any other part of your house. Burning carpeting is actually worse.

[Anonymous]

I have a question -- where do you folks find such thick (over 1") foam? My local Home Depot only carries 1/2" or so extruded foam insulation (the pink stuff). The thickest stuff they have is 3/4" white thick styrofoam stuff called "Shelterfoam" for insulation. I asked one of the guys in the insulation area about thicker foam boards and he looked at me like I sprouted an extra head. [%-)]

I picked up a six-pack of the Shelterfoam to use as the bed for the yard I'm building. Anyone ever used this stuff? Anything I should watch out for or know before I start building with it?

[grayfox1119]

Go to the web site www.woodland scenics.com and check out all the foam products they have made especially for model railroad layout work. And Paul, sorry to differ with you, but the foam that is used by Woodland Scenics is NOT toxic. The kind you are referring to is the packaging foam. That stuff most certainly gives off toxic vapors at melting temps, so never use this. Woodland Scenice has 1", 2", 3", and 4 inch foam,as well as risers for elevation of tracks at various % grades. I have used this product and it is very good. They also have great video (VHS) to show you how to use their products, as well as several books.
Hope this helps you,
***[:)]

[grayfox1119]

Correction on Woodland Scenics web site, it is www.woodlandscenics.com

I didn't remove the space in the previous reply!!

***[#oops]

[orsonroy]

QUOTE: Originally posted by jsalemi

I have a question -- where do you folks find such thick (over 1") foam? My local Home Depot only carries 1/2" or so extruded foam insulation (the pink stuff). The thickest stuff they have is 3/4" white thick styrofoam stuff called "Shelterfoam" for insulation. I asked one of the guys in the insulation area about thicker foam boards and he looked at me like I sprouted an extra head. [%-)]

I picked up a six-pack of the Shelterfoam to use as the bed for the yard I'm building. Anyone ever used this stuff? Anything I should watch out for or know before I start building with it?

Joe,

The foam everyone talks about using for layout construction is actually insulation, something you Rebs in VA don't really know much about (compared to us cold-weather Yankees up north). Most Home Depots will special lorder the stuff, but will insist on a monimum quantity which will probably be too large for your needs. I'd try concrete and foundation supply companys; the extruded foam is used as formers for pour jobs.

I've never even heard of shelterfoam...

[jwmurrayjr]

QUOTE: I picked up a six-pack of the Shelterfoam to use as the bed for the yard I'm building. Anyone ever used this stuff? Anything I should watch out for or know before I start building with it?

Joe,

The Shelterfoam sounds like the white beaded foam, not the dense extruded Styrofoam. My opinion is the that the white beaded stuff is very much inferior to the extruded (usually blue or pink) in terms of strength, workability and texture. The extruded foam has a very smooth texture that can be carved to represent realistic rocks, walls and concrete when painted. And it takes latex and acrylic paints well.

Also you can exclusively use the 1/2" blue foam (I did.) You just need to adjust your methods a bit. I used some of the white foam before I realized what a difference there was in the products. You can see some on my site. It may have its uses in filling large spaces when it will be covered by plaster cloth or other foam, but I wouldn't use it again, especially on the table tops.

Just take it slowly and don't be afraid to rework areas that don't please you.

Have fun![:)]

[Anonymous]

Thanks, Jim! It's hard to tell if the Shelterfoam is beaded, as it looks pretty smooth. But it's not expensive, which is a plus -- a pack of 6 2'x6' (if I'm remembering the size correctly) pieces runs about $6, while 2'x8' 1/2" pink stuff is almost the same price for one piece.

So like you say, I'll give it a try, and rip it up if I don't like how it works. [:)] I figure it can't be too bad for a flat area like a yard, but we'll see.

[Anonymous]

QUOTE: Originally posted by orsonroy
The foam everyone talks about using for layout construction is actually insulation, something you Rebs in VA don't really know much about (compared to us cold-weather Yankees up north). Most Home Depots will special lorder the stuff, but will insist on a monimum quantity which will probably be too large for your needs. I'd try concrete and foundation supply companys; the extruded foam is used as formers for pour jobs.

Yea, I suspected that was the case -- since it rarely gets much below 30 degrees around here, thick foam insulation isn't common. And the thin stuff is pretty expensive. So maybe I'll end up sticking with the Woodland Scenics stuff if the Shelterfoam doesn't work out.

Thanks!

[Anonymous]

Don't waste your money on the Woodland Scenics stuff. I live outside of Atlanta. It took a few calls but I found two places that sold 1" and 2" 4'x8' sheets of Extruded Polystyrene - the blue stuff. It cost less than $9.00 a sheet.

Try commercial contractor suppliers. Home Depot helped me locate one.

[Anonymous]

Polystyrene is the trade name, for the solid type (blue&pink) ,while Styrofoam is usually the white beaded foam that is not desireable for carving.

[jwmurrayjr]

QUOTE: Originally posted by rororo

Polystyrene is the trade name, for the solid type (blue&pink) ,while Styrofoam is usually the white beaded foam that is not desireable for carving.

Actually the blue foam is Dow Styrofoam, their brand name. See their web site.

http://www.dow.com/styrofoam/

Owens Corning makes the pink stuff:

http://www.owenscorning.com/

The white polystyrene foam (They are all polystyrene) is the cheapest and is often (usually) molded instead of extruded.

http://www.favonius.com/soaring/foams/foams.htm

Foam, foam foam....

[^]

[Anonymous]

I used the store search on the Owens Corning site, and it tells me all the local Home Depots are the place to buy it. [:P] I'll just have to try some other HDs in the area, and see if they have the thicker stuff.

Actually, I'm going to drop by my LHS tomorrow to pick up some stuff for the new layout, so I could probably ask them if they know of a local source. I'm pretty sure they'd have an idea or two.

[raykaczmarek]

I use 1/4 plywood, cork roadbed. I frame 1x4 frame.. I layout is flexxable contract.

[grayfox1119]

Not all foam is chemically the same. Some types give off harmful fapors when heated, as you would if you were using a hot knife or hot wire to do some shaping or running holes through the foam. I am researching the types of white and blue polystyrene to see if they give off harmful vapors when heated. We all have enough things in our food, air and water to give us cancer, we don't need to have our noses in it at close quarters do we guys????

***

[CBQ_Guy]

QUOTE: Originally posted by orsonroy

QUOTE: Originally posted by CBQ_Guy

You've gotten a lot of good advise here, so there's not much I can add except to consider that when foam burns it gives off toxic, make that lethal fumes!

Second, ignore comments concerning Homasote being affected by water and moisture...just ain't so. I was surprised to see that this model railroad urban legend is still around.

Good luck with your layout!

Paul,

sorry to contradict you, but from my own experiences, just the opposite is true. In high school, I worked in a lumber company, and have seen Homasote swell to six times it's normal size due to just humidity. And according to Dow's MSDS safety sheets, as well as independent tests conducted by the University of Oklahoma (both available online) foam is no more dangerous (and no more safe) than burning any other part of your house. Burning carpeting is actually worse.

Oh well, Ray, I guess we'll just have to, as they say, agree to disagree. [:)]

I have seen Homasote sitting outside in rain and snow for months not swelling or warping at all. I have had a leaking pipe "rain" on it on the old layout and after mopping up the water and blowing a fan on it overnite, I had no problems whatsoever and none of the tracked moved or kinked either. One guy on one of the Yahoo lists actually took measurements before and after soaking a scrap piece of Homasote in a bucket of water, with no appreciable changes in dimensions, and again no swelling whatsoever. Here in the Midwest most of my friends use it in their basements, some with water leaking in through the foundation after a heavy rain, with no dehumidifiers going, and they have never had any problems with expansion/contraction issues, either. Finally, IIRC Homasote's own website only states the expansion/contraction factor to only be something like 1/8 inch over eight feet. Good enough for me.

As far as the foam goes, I'm pretty sure I saw on a TV program a few years back that, as it burns it gives off cyanide gas, but could be incorrect as to the exact type of deadly fumes involved. Also, it reportedly drips flaming strings and chunks of molten plastic as it burns. Personally, I would NEVER even consider using foam unless possibly it was encased in plaster all around.

Well at least Richard gets all sides of the equation here to help him make a better and informed decision. And that's what the Forums/List are all about, IMHO.

Take care.

[grayfox1119]

Here is the info that I found regarding extruded vs expanded foam. This is why expanded foam cost a little more, but is safer to use. Using a hot knife or hot wire shaper/cutter is so very easy and efficient that I see no need to use saws, but to each his own:

"When the sheets of extruded foam are extruded, there are gases trapped in the hollow cells, produced during the chemical process. When one cuts the foam, those gases are released.
We do not recomend using our hot wire cutter in those sheets of extruded foam for that reason. But if you do, always do so in a well ventulated area.
And they are cheaper, since the process is cheaper.
Our expanded foam is done with heat, like popping corn, in a mold. "
There you have it guys !!

***

[Anonymous]

I'm rebuilding my N scale layout after the most recent of five moves (mostly overseas). I'm interested in using foam but wonder how I can since my layout is set in my ancestral home of south Germany and uses a cantenary system. Anchoring the metal masts for the functional overhead wires is the problem.

grayman

[Anonymous]

FYI here is an interesting link I came upon yesterday about using foam for your layout. It is put up by the Boulder Co Model Railroad Club

http://bcn.boulder.co.us/recreation/bmrc/bmrcfoamlayoutclinic.htm

[fischey]

Three comments, structure, safety, and catenary poles.

Foam board, even 2", will sag if not supported. The good news: It doesn't take much to support it.

Second: Foam offgassing from heating it is dangerous. Period. So when you use cutting tools, ventilate very well. Note that if a mfr claims foam offgassing is no more dangerous than other combustibles, the comparables include chemicals, paints, and other things than wood. Lastly on this subject, Styrene is a suspect chemical (but not the only one) in the pathology of Parkinson's disease. While it is extremely stable as a foam roadbed and scenery core, think about this when you turn it into a gaseous form. Augh!

Third: planting overhead catenary poles is possible. I also model European with Sommerfeldt poles, and have an 8' foam section which has been stable for years. Try glueing a block of wood into the foam core surface (you can carve out the necessary hole or depression needed for proper elevation). When dry, drill the appropriate sized hole into the wood block to allow your catenary pole to be inserted with glue. Let dry. The result will be stiff enough to permit you to mount and tension the catenary wire sufficiently. The poles are removeable and clean up OK if you use the right glues.

Happy Foaming.

[macchoo2]

A word of advice, panit ALL SIDES ! In time, this product breaks down. Be for worn. Gary

[CBQ_Guy]

QUOTE: Originally posted by macchoo2

A word of advice, panit ALL SIDES ! In time, this product breaks down. Be for worn. Gary

Which product, foam or Homasote.

(Eventually, EVERYTHING breaks down, give or take a few million years.)

[Anonymous]

Has anyone used the very thin pink foam from HD ?? It comes in folding sheets and I believe 1/4". The reason I ask is that I have a layout that is built in 2'x4' semi-modules. I used 1x3's and 2x4's for the frame and 3/8's inch plywood in precut size of 2'x4'. I have the bench work done, and the track work done on cork. I am getting close to starting the scenery and would rather not put it down on bare wood (hard to get trees into it).


Any one else in this predictiment ??

I have some pics if that would help:

http://community.webshots.com/user/nhguy21

Thanks,

Josh

[Anonymous]

Haven't used any foam that thin yet. It would be a good base layer in flat areas and along the already laid tracks, though it may not be thick enough to support your trees. You could easily drill a little ways into the wood decking if necessary. If you're planning some hills, I'd lay in a supply of thicker foam to make the work go quicker and probably a litlle less costly. Easy to cut with a utility knife and shape with a Stanley Surform tool. (The best investment I made, recently.)

Wayne

[orsonroy]

QUOTE: Originally posted by nhguy21

Has anyone used the very thin pink foam from HD ?? It comes in folding sheets and I believe 1/4". The reason I ask is that I have a layout that is built in 2'x4' semi-modules. I used 1x3's and 2x4's for the frame and 3/8's inch plywood in precut size of 2'x4'. I have the bench work done, and the track work done on cork. I am getting close to starting the scenery and would rather not put it down on bare wood (hard to get trees into it).


Any one else in this predictiment ??

I have some pics if that would help:

http://community.webshots.com/user/nhguy21

Thanks,

Josh

I looked at the fan fold pink foam as N scale roadbed material, but opted against it. Too much scrap, and the stuff's way more expensive than a sheet of 1/2" pink foam ($28 versus $12). The 1/4" fanfold foam will be too thin to really hold onto anything stuck into it, so I'd suggest at least 1/2" foam (and you'll save money in the process!)

[Bikerdad]

The strongest foam you can buy will be found by calling a commercial refrigeration contractor, who can point you to their source for the foam they use under the floors of walk-in freezers and the like. You can stand on this stuff in high heels and it won't dent. Dow makes different "grades" of hardness, in different thicknesses, for different applications.

A possible free source, if you happen to live in the right area, would be R/C plane manufacturers (they use a lot of extruded foam these days) and possibly custom surfboard shapers. Whether the hassle of getting and using free leftovers is worth it depends on you.

Wow, that Augusta Station is awesome. I wish I would have known about it earlier, could have fit it into my travels. sigh...

[Anonymous]

Josh,

Since your track is already laid, I would still look at the 1/4" foam to avoid having all your roadbed at the bottom of deep foam trenches. Use it sparingly along the track and use thicker foam to build up other areas.

An alternate: I've been mixing my own two-part Polyurethane foam, pouring it on (free) bubble wrap & reinforcing with (free) recycled fiberglass screening. The result is a sheet about a quarter inch thick. Detailed info for this method is at http://www.bragdonent.com though I buy the actual foam material for half the price elsewhere. (Sorry, Bragdon.)

I feather the edges with Liquid Nails One-Step Spackling. It's super light, which is why I use this more costly product. I also use it for sculpting the foam rock cuts.

Wayne

[Anonymous]

Thanks guys. I have to go to work at Home Depot tonight, so I will take another look at it. There is only a few spots I want to use the insulation. Mostly in areas where there are buildings or open space. In 2 places there will be piles of coal and pulpwood, so I might use some higher stacked and shaped.

I will let you know what I find.

Josh

[Anonymous]

Well the sheets are 3/8" not 1/4" but thats fine. It was 4' wide and 10-20 feet long. It was about $ 36.00. I think I will give it a shot. It should work good under buildings and other areas with out track.

The only other obstical is that I have done some of the roads with joint compound, so this may need some tapering to make them line up.

Is the foam attached with liquid nails ??? I think that is what I will use.

Josh

[Anonymous]

QUOTE: Originally posted by nhguy21


Is the foam attached with liquid nails ??? I think that is what I will use.

White glue works quite nicely for foam to wood or foam to foam. I've heard conflicting reports about
Liquid Nails adhesive. Some claim the mfgr. says not to use it on foam, others report good results.
A good practice is to try it on a small test piece first.

Wayne

[Anonymous]

Dickiee: I see you are from N Michigan. Your construction people probably use styro in building houses, much thte same as here in Ontario. I found that if you approach the site foreman at a housing site in a proper manner, he will usually let you have their scraps for free. I got tons of it that way. It's usually thinner stuff but the beauty of it is that the foam can just be stacked and glued to make it 2" or more thick. I cut it with an old thin-bladed kitchen knife. My HO lay-out, the Abbinnagh, Wurke & Onnddagh Railroad (say it fast out loud) is a 9'x13' modified E shape. It is solely 2" foam on 1x3 L-girders spaced at 16". Piece of cake!