to foam or not to foam

has anyone tried using canned expanding foam for scenery or for constructing mountains? i`ve been mulling this over for awhile it seems like it would work in a large area,but may be a real mess in smaller areas, if anyone has tried it i would like to know how you did it also how it worked out.
thank you in advance for any help. roy[:D]

Warner Brook, Read the can carfully they make a high and a low expand spray foam. I believe you can mist it with water to get it to skin over more quickly, but read the can. Also use in well ventilated area, I had a hell of a flash fire foaming in around an exterior door in a cellar once, hot water heater pilot light set off the vapors that had settled near the floor. My feet and legs got hot fast, but as quickly as it had started it went out[oops] boy did I feel stupid!

it has been done in recent Model railroader projects

thanks carpenter matt— i think i`ll forego that idea as of now. i have a wood heater that will probably be on untill the end of april.my wife said i give off enough vapors.[xx(][wow]

I read something about someone using this stuff once, but I can’t remember where I read it. They sprayed it then carved it with the usual tools–knived, saw blades, wood rasps, etc. I remember the final product looked pretty good, especially using it for rock outrcroppings along mounainsides.
Ron

Malcolm Furlow used it on his San Juan Central, IIRC.

One thing to watch out - it sticks to EVERYTHING. Wear rubber gloves, unless you want crusty hands…

Rob

Keep a can of acetone around to clen whatever it gets on.

I’ve tried using it to create hills and stuff, and it doesn’t really work that well. It’s expansion rate is unpredictable, it’s spread is pretty uncontrollable, and it’s not easy to carve (it’s easy to cut, but that’s not the same thing). And while the top layer might look OK, once you cut into it you end up exposing it’s Swiss cheese interior. It might work OK as a sub base if you were planning on covering up everything with plaster gauze strips (why bother?), bu tI don’t like it as a stand-alone scenery construction technique.

For my money, stacked foam sheets and a bit of carving are the bestt way to make scenic contours.

orsonroy
thanks for the input,i guess some ideas just are not worth it.

warner brook

I’ve used it with varying success in the past. As some has mentioned, it sticks to everything, so you need to be careful with it. Also, if there isn’t enough room for it to expand, it can do interesting things to surrounding foam structure. When solid, it’s also much less dense than extruded foam, so it works a lot differently.

I have found it useful in filling gaps in laminated or shell foam structures. However, I wouldn’t use it as a major component of scenery landforms.

Ray

I remember an article in Classic Toy Trains that explained how to make an s-scale tree skirt using foam in the can. It gave some helpful tips on how to shape the stuff, color it, etc…

We tried it on a friends layout with some success. Towards the back of far hills and along the backdrop, he squirted it moving the can up and down as it was coming out, to create bumpy high and low spots. After it had dried he painted with latex paint in an earth color. Then he dumped on bag after bag after bag…of Woodland Scenics lump foam (wi***hey sold this by the bale!). Over this he sprayed the matte medium scenic cement by WS to glue it all down. The effect is supposed to be of distant tree covered hills. It doesn’t look bad though it doesn’t look great, IMO, either. The foam can be a bit messy if you’re not careful though.

Hope this helps.

I used this product for sealing an open area between beam and lintel over my garage door. For that purpose the product worked well. However, after seeing the characteristics of the “expanding” action, it seems to me that it would have limited applications in scenicking. If you wi***o experiment, by all means, please wear “throw-away” gloves. As mentioned above, the stuff is very volatile, hard to manage and a mess to clean-up mistakes. With so many other options, personally, I can’t recommend it. Regards

I have. I have used Great Stuff and Touch-n-Foam. Both are liquid foam gap filler. Great stuff comes in three “expandiblities”, I have used the wide gap filler with much success.

The key to success is to cover everything you don’t want covered and go slow! I have made a mountain exclusively from this stuff. Keep in mind it is very smelly and you should use it in a well ventilated area. For me, I’m in my basement, so it’s not well ventilated. I spray the foam at night, and let it cure overnight and all the next day. Then when I get home from work its dry and the smell is gone. I can start cutting it to shape right away.

Generally, you want to over fill the area you want covered and cut it back. But be carefull not to over fill to much. That’s the tricky part. The foam expands by design and will spread out, covering everything in it’s path, like slow moving lava from a volcano. Make sure to mask off your track and anything else you don’t want covered.

If you have a solid table no worries, but if you’re using an open design benchwork, fill gaps beneath the foam with scrap extruded foam or bead board.

Best of luck.
Trevor

Just thought of a great use for this product which would make an interesting home video. Buy a cheap plastic Diner that you won’t miss; have the wife or one of the kids start “rolling film;” release the foam while spraying same with aresol red paint and before you can say Michael Moore; you’ve got a home version of the “Blob.” No, eh?

Warner Brook, okay, give it a try, BUT…not on your layout… just yet. Use it to learn on another mockup or something.

I think you will abandon the idea altogether, but it would be useful to hear of your experience in the days ahead.