Hard Shell or Extruded Foam - which is best?

[Anonymous]

I am at the point in my layout construction when I have to decide which scenery material is best suited for my layout. It's an HOn3 version of Malcolm Furlow's Hon3 as seen in MR books and magazine. I realize he used foam, but in the book he mentioned that he used this only becasue his layout was designed to be moveable. Mine is a permanent one taking up an extra bedroom. I am at the point in construction now where I am to build the mountains and I would like to know what is the material of use today. I'm sixty and have been a a procrastinator, collector and dreamer of the hobby for fifty years now and have finally decided to get my feet wet by building a layout. Old school dictates hard shell but extruded foam looks tempting too. Which is the easiest and best scenery material? Oh, if extruded foam is the best, don't you end up using a foam type plaster over the foam?

[Anonymous]

I built my layout in 1990, with hardshell over wadded newspaper. I am rebuilding portions now, and almost always use foam. My first version was desert, with few trees, but I'm "moving" it to the midwest. The foam underneath gives you a better base to plant trees. So, the area you are modeling does have an influence on your choice.

Of course, if you are procrastinating for fifty years, there is a chance you are overthinking the subject! Once its all covered up with ground foam, no one will know, and in fact, there is no reason not to do both types, depending on whether you can find the foam when you need it (I got big sheets at a contractors supply store rather than use the WS for bulk uses - its cheaper)

so, just try them all. AFter all, model railroading is fun!

[Anonymous]

I have developed my scenery technique to the point now that I can't understand why anyone would ever use hardshell; I know that I certainly will never deal with its mess again. I use a foam base, although rather than use sheet foam products I prefer to use expanding foam insulation; it is much more sculptural. Over the foam, I place my home-brewed papier-mache mixture, which is primarily Cell-u-clay brand cellulose mixed with water, with joint compound thrown in. To that mixture, one can add all manner of coloring agents (I use brown and black tempera paints, since they're cheap) and real dirt or gravel for texture, even scoopable kitty litter for some interesting textural effects. I mix up on plastic cup's worth at a time, and apply it using a plastic spoon (metal spoon is better if you can part with one), troweling on a very thick mixture which I can "carve" as I place it. The smooth bottom of the spoon works to smooth out the finished surface, while the edge can be used to rough in striations on exposed rock faces. As it dries, and it takes a nice long time to dry, one can get more detailed with carving, and I have also been successful in taking real stones and setting them into the "plaster"; with some attention to detail, one can create a mosaic of natural rocks to serve as a cliff face, rather than have to sculpt or mold it all.

Hardshell has a setting time, not a drying time, and once it's cured it is done, aside from any dry carving you might want to do. My method results in scenery that can be re-wet and then reshaped as desired. Hardshell produces a shell that is white throughout, so when you go to place a tree, you drill a hole and leave a little unsightly powder pile. With my method, placing a tree can be done with just a knife or icepick, as you poke a hole through the soft plaster layer and into the foam beneath. The papier-mache is dirt-colored, assuming you've included the right stuff in your mixture, so any chips or cracks are not a detriment. I strive to create a realistic-looking ground surface, as though no plants grew there at all, just barren earth, and then I add regular ground foam on top of that. It takes very little of the green stuff to complete the scene, because most of the "heavy lifting" is being done by the superior plaster layer. Even in the heavily-forested northeast, there's a lot more brown in the scenery than you think, and not near as much pure green as we tend to model; by concentrating on creating a model of the bare earth, you'll discover just how much foliage is right.

[cp1057]

I use extruded foam almost exclusively and recommend it to anyone. It is very easy to carve and work with. I use an old steak knife (my wife still wonders where it went!) and an old spoon with the bowl ground down to make an edge. You should have an old vacuum cleaner handy to clean up the shavings as they take on a static charge and stick to most everything! Fancy lads use hot wire foam cutting tools, but only where there's lots of ventilation.

Depending on the contours of the scenery I try to get 2 inch thick pieces and glue them together with white glue or latex adhesive to make taller formations. Once all the scenery contours have been shaped, I paint everything with ordinary tan coloured latex house paint. It's very economical, doesn't attack the foam, and cleans up with water. Ground foam scenery material can either be sprinkled on the wet paint or applied using a diluted coat of white glue.

Don't use any glues or paint or scenery material that reacts with the foam. If in doubt, test the material with a small sample piece of foam. Not only will anything solvent-based attack and ruin the foam, it will give off vapours that are really, really bad for you! As I mentioned, latex house paint, ordinary white glue and latex adhesives are okay.

Charles
Hillsburgh Ontario

[Anonymous]

It depends on how old and set in your ways you are. Old fart hard headed know it all modelers use hardshell and homasote and trash anyone who use different. What amazes me is they own a computer to post with since they are so set in the 1960's. Enough said? FRED

[Anonymous]

i fit into the "old fart" group, but i have been active since i was a "young stud". i find the best system for me is a combination of hard shell and foam. lately i have been using foam as a base and then applying hard shell detail such as rock surfaces cast in rubber molds and applied before the hard shell is fully set. of course i cheat just a little, i live in the west with mountains very close and i make my own rubber molds using latex rubber with a mesh reinforcing.
just a word of caution. hard shell can be messy, but so is foam if you try to cut it with a saw. you will never get all the foam residue (high static foam sawdust) totally removed from your layout. purchase a hot knife, or make your own and use it exclusively to cut foam.
i also use hard shell when filling in under bridges and other similar structures on the layout. i use cardboard formers with a nylon mesh over it, then apply the hard shell. i use the same technique when closing the scenery in around tunnel portals. trying to cut the foam to shape and then fitting it into an existing scenery base has not always worked well for me. i have damaged scenery already in place and that has created some real heartache. using insulation foam in cans for the same type areas has not been successful for me either. the expansion of the foam can be excessive and create additional work, mess, disillusionment, even frustration. i find both systems work for given applications. take your pick, find what works for you in each situation, and go for it. .

[wp8thsub]

Which material is "best" is probably determined by one's personal tastes. Do you visualize better by building a shape up from nowhere or by carving it out of something?

I've used both hardshell and foam. I positively hate using foam. It's faster and easier for ME to build up the scene from cardboard strips and install a cheesecloth layer onto which I bru***hin plaster. As for mess, you get different kinds; either plaster drips (easy to control with newspaper) or foam bits everywhere.

Try both for yourself and see what works best for YOU before committing to one or the other for a whole layout.