Layout base

[Anonymous]

Hello all , I'm new to this type of model building. I posted a question regarding, is it possible to use a 2 inch 4 by 8 sheet of rigid foam insulation on top of a plywood base. I could not find Homosote at Home Depot or Lowes and wanted to also be able to carve out the foam for a small harbor and a river.

I'd really like to begin building a layout--- Help!!

Thanks for any replies-- Bob

[orsonroy]

Bob,

Using 2" extruded polystyrene foam insulation sheets (the pink or blue stuff, NOT the white beaded stuff!) is a great way to build a layout. I'm currently building a large 12x25, three level layout using 1/4" plywood and 2" foam. Carving the stuff with simple hand tools is simplicity itself (it does get a little messy, so have a shop vac handy!)

[Anonymous]

Ray;

Thanks for the reply, this is R-Tech Insulfoam and it is white and probably beaded-- It feels firm and solid, what is the problem with this material?

Bob

[Anonymous]

The white "beaded" foam is not as strong as the other material, which is extruded in one piece, rather than beads pressed/melted together. The white styrofoam is ok for landscaping and "filling" space (Dave Frary does this), but maybe not the best for laying track on. It is also more easily damaged than the extruded foam, and is extremely messy and difficult to carve.

However, since you intend to put it over a plywood base (how thick?) you probably will be ok. Where you really need the strngth is if you want a lightweight layout and therefore skip the plywood, putting the foam directly on your frame and/or risers.

Andrew

[Anonymous]

Andrew, Thanks for the response.

The plywood is 1/2 inch thick. I'm starting out with a 4 by 8 sheet. I just couldn't find Homosote, so thought this beaded white Rigid foam seemed firm enought to lay my track, etc. on; and, since it is 2 inches thick , that I could carve out a river and harbor.

Bob

[Anonymous]

Bob -

When carving the white beaded styrofoam, things will get very messy! You should use a knife that is as sharp as possible (maybe a filet knife or something like that), or use a hot wire tool. The hot wire tool will REQUIRE lots of ventilation.

Andrew

[Anonymous]

Andrew:

Thanks for your replies. This is my first effort at MR building, I'm going to buy a hot wire cutter. and give it a go.
Would you suggest coating the styrofoam sheet with anything special?
Bob

[Anonymous]

The white beadboard styrofoam is especially sensitive to any solvent based substances. So be sure to test anything you are unsure about on a scrap first! You should be safe with latex paint, which is what a lot of people use for their first coat over the foam. You can get a mis-tint from the "as-is" pile at your local Home Depot. If it is not quite dirt coloured enough, they may add some tint for you if you are not too picky about it.

One other thought that just occured to me is that instead of a hot WIRE tool, you might want to try the hot KNIFE tool. This makes actual carving (not just cutting) easier. Be sure to ventilate!

A general comment - I made a small diorama (about 8 inches x 12 inches) to try out a lot of my techniques before I committed to them on a larger scale (so to speak). Took me about a week, but provided some really useful insight. On this little chunk of real eastate I put: 4 kinds of trees, 2 kinds of ground cover, 2 types of fencing, two types of ballast along about 12" of track, a rock face, a sand/gravel road, a utilitiy pole, a sign, and also tried a little bit of water (the water did not work well...). You might want to try something similar to get you going.

Andrew

[Anonymous]

One of the best thing you can do before starting construction is buying this book, it will explain and answer most of your questions if not all I'm sure.

http://store.yahoo.net/kalmbachcatalog/12175.html

[Anonymous]

Many thanks to andrew, ray and neerie for the info. I'm ready to give it a shot.
Bob

[Anonymous]

Homosote can be found at Cox lumber][8D]

[Anonymous]

One thing I noted from another forum... Foam is highly flammable... use it as sparingly as you can afford....
I'm not saying Don't use it at all... but keep it away from open flame, sparks, fuels, butts (not the flesh kind <grin>) and such.
Go into this with eyes open!

[CBQ_Guy]

QUOTE: Originally posted by jazzypogo

I just couldn't find Homosote, so thought this beaded white Rigid foam seemed firm enought to lay my track, etc. on; and, since it is 2 inches thick , that I could carve out a river and harbor.

Try...

http://homasote.com/where.html