foams or molding materials

[Drew]

Hi,

I'm not anywhere near making scenery yet. I haven't even got a layout built
or anything. I'm just curious.

Ok say you have built your benchwork and plywood is down. What do you put
down on, after, the plywood.
Pink Foam, Homosote ( what others are there? )? Why do you need these extra
materials? Strength? Noise? Does it help in making your layout more
realistic? Isn't the cork you put under the track enough?
Oh, one more thing, What do you use to mold scenery? I know they have
plasters for doing that, but what is easiest to work with? I know Stiro
foam would be last on my list. It's loud and very messy, and I think hard to
work with. My opinion.

Thanks!

Drew

[Greg]

I work with extruded styrofoam or styrolite. Its not the chip foam.
There are no squeals when cutting or breaking. The only mess to it is
when you scrape it and the pieces fall to the floor. All you need to do
is sweep it up or use your hands and put it in a bag. These pieces make
great rocks for river beds and embankments. I just made some mountains
on Monday . You can see how I did it at
http://sites.netscape.net/agsgreg/constr
Greg S.

Drew wrote:
>
> Hi,

[Birk Binnard]

I use 1/4" fiberboard as a base (plywood would be better because it is
easier to nail into) with cork roadbed nailed on to it. I make my scenery
using a base made from a spray can of expanding foam which I shape while it
is still soft and then cover it with Woodland Scenics plaster cloth. I
hand-spread a thin layer of Woodland Scenics Hydrocal over the plaster cloth
after it's dried so that there is a consistent base for painting. This
results in scenery that is very strong, light, and easily changeable. (I
have cut car clearances out of finished hills with a track saw or X-acto
knife.)

The expanding foam stuff is interesting. It is cheap (a big can costs $3)
and it sets up to a strong, light, easily workable material. It comes out
of the can looking sort of like yellow whipped cream, and begins to expand
immediately. If left alone it will expand to 400 -- 500% of its original
size. Total curing time is about 4 hours, but it develops a smooth, dry
skin after about 10 minutes. At this point you can easily push it into
rough shape with your fingers. You may have to re-do this several times
because it may keep expanding.

After the foam has dried I shape it with saws, knives, screwdrivers,
scissors, or whatever seems appropriate. It is just like styrofoam at this
point. After that I cover it with a single (sometimes double) layer of
Plaster Cloth, and after this has dried I cover that with a thin layer of
Hydrocal. The Hydrocal fills in the small holes in the cloth and also
provides a consistent base for subsequent painting. The plaster cloth &
Hydrocal steps are messy, but quick to do.

One problem is that if you get the foam stuff on your clothes while it is
still wet it will never come out. Not ever. I don't know how they do that,
but they do.
--------
Birk Binnard
Peninsula Software/HOHoist
http://www.birkbinnard.com/hohoist

[Roe Thomas]

> still wet it will never come out. Not ever. Yeah, and if you get it on your hand's it'll only take a week,on so to get it off. Roe I don't know how they do that,