Hi all,
I need to make some rocks to add to my mountains and areas around my track.
I don’t know where to start so can someone please help me.
Thank you in advance
I recommend getting some rock molds and a good plaster. You can make the rocks at your bench, or apply them to the layout after a few minutes of curing.
http://woodlandscenics.woodlandscenics.com/items.cfm/RockMolds
I further recommend getting a few videos as how-tos. I have Joe Fugate, Paul Scoles, and Dave Frary - they are all good.
http://model-trains-video.com/index.php
http://www.micromark.com/ADVANCED-TECHNIQUES-FOR-REALISTIC-SCENERY-DVD,8796.html
-Tom
If you’re new to the art of making rocks, latex molds and casting plaster is a good place to start.
You can also buy styrofoam rocks pre-shaped and colored, but they’re expensive.
Personally, I use molds and hydrocal for large, free standing rocks (I model New England, where glaciers just dumped some really big ones and left them lying there). For rock faces, I get a picture of what I want the finished surface to look like, cover the area with Sculptamold about 1/2 to 1" thick, and carve it with a palette knife while it is still wet. Both vertical and horizontal cracks can be made using the edge of the blade, deeper clefts by either removing whole chunks or pressing in with the flat of the blade. Add some talus at the bottom and paint to match the photo. The great thing about this method is that you don’t have to worry about all your rocks looking the same after a while.
Real rocks work fine too - but in large quantities they’re not for portable layouts - too heavy.
Don’t forget to scale down by the proper factor. Also you can use the flat sides of rocks vertically to represent hillsides. You don’t need real depth - only perceived depth. Kind of like those fake stone and brick stucco products on some houses.
Real, carved foam, carved structolite, cast plaster. Oh, and don’t let the bare hillside scare you. It has many more trees and detail now. This was an early photo [:)]
Experiment and have fun.
Karl
PS: 
I bought a few Woodland Scenics molds and used cheap Plaster O Paris.
http://sitesearch.ehobbies.com/results.php?page=2&query=rock+molds
http://www.bragdonent.com/smpic/item2.htm
Mix your plaster into your water.(Not water into plaster) This produces less air bubbles in your castings. I tried buying some liquid latex and using real rocks to make my own molds, but it’s really wasn’t worth it.
I’ve used both Woodland Scenics and Bragdon molds. The WS rocks were cast using Hydrocal, a fine-grained, lightweight casting plaster. My guess is that Plaster of Paris, which is cheaper, would work just as well.
The Bradgon process (see www.bragdonent.com) uses a 2-part casting foam instead of a hard plaster. The “rocks” come out very lightweight, and are flexible until they’ve set for a while. After that, they can be softened by applying heat with a hair dryer. I really like the results:
The Bragdon rocks take a lot longer to make than Hydrocal rocks, so you might want to get your feet wet with plaster casting first.
Where can you find Plaster O Paris??
Just about any hardware store or the big box stores should carry it. I got mine at Lowe’s because they carry it in large plastic tubs as well as bags. Since I will store it in my basement, I was concerned about dampness causing it to harden.
Another option for making rocks is using Sculptamold. It has a much longer working time than plaster and its rough texture makes it good for modeling rock faces. Here is a sample of Sculptamold rock faces and outcroppings on my layout:
Hi: That’s good advice to obtain some scenery books and tapes. They will give you the basics, materials, methods, and coloring. Then, give it a try. In this scene, I used 3 different materials and methods. WS rubber molds with Hydrocal Lite, stacked ceiling tiles, and carved Sculptamold/Structolite mix.
Thank you for the answers and pointing me in the right direction. You both have done a beautiful job with your mountain work Absolutley fabulous! I will be working on Pennsylvania and New York hills and worn mountains. I am working on a New York Central and PRR motif on my first trainboard --HO scale – 4X8. If you got any photos of those types, or have seen any anywhere, please let me know. But, some of the work I have seen on this forum, including yours, is just tremendous. Nice!
Mark
Wal Mart has PoP large tubs too. A word of caution with casting with Sculptimold. It doesn’t accept stain as well as plaster. You get little shiney spots from the fiber that’s mixed into their product. Doesn’t really produce fine detail either. (at least that was my experience with it.)
Do you need to use something to prevent the plaster from sticking to the latex mold? Also, if the mold has a lot of depth, will the plaster conform to its shape, or does the mold need to be “filled” with plaster?
Hi Harry: I spray WS molds with “wet” water. If you use Hydrocal Lite, it will fill the mold and pick up all the details in the mold. I’ve done some that were at least 2" deep.
If you’re going to cast, you need to use hydrocal or plaster of paris. I’ve never been able to cast with Sculptamold for beans. However, the secret to getting rid of the chunks (actually recycled paper) is to make sure you use enough water and mix it well. Use slightly diluted acrylic paint to color it. If you try to stain it with water-based paints, it doesn’t work so well.
Sculptamold excels at making rock faces which you carve in place. If you want more “grain”, throw a handful of kitty litter (UNUSED) in it.
Agreed, although sometimes Ultracal is easier to find.
Yep. Sorry. I should have said “Pure plaster without the paper and glue in it”.