Looking at making some rock outcroppings on my layout. Nothing huge, just 4-5 smaller ( approx 10"L x 3-4" H) croppings. These would be stand alone formations with some shrubs/bushes around the base.
I have been using MR “Basic Scenery” book which I picked up a few months ago with great success. Mr. Sassi recommends using Woodland Scenics Subterrain Foam Putty for outcroppings. Looks easy, realistic and light. I have not heard much about it on here.
Any input/suggestions before I pick some up? Again, I am not making mountains/cliffs just some smaller sized outcroppings.
I haven’t tried that. For most of my rock work, I use rubber molds and cast them using Hydrocal. This is a plaster material that is light and very hard. It takes paints and stains well, too.
I’ve also used a two-part foam casting material from Bragdon, www.bragdonent.com. This is a bit more work, but the results are very high quality, and I think they’re a few steps up from simpler techniques.
No experience with that product, but sounds interesting. Don’t know how much it costs or you have to use, but perhaps Lou’s advice gives some idea about that.
The old standby for rock casting is plaster produced in molds. Woodland Scenics also sells molds (plaster, too). If you get several molds, turn and break up the results in addition to using them whole, you’ll be able to make lots of rocks at very low cost. Might be worth running the numbers if budgets are tight to compare.
Depending on what rock effect you’re trying for, Sculptamold can produce some nice rocks. It’s easy to mix and use, much more forgiving than plaster. You can texture or otherwise treat the surface for different effects. It’s also lighter than plaster when dry, which can be a factor for those who need portability as with modules, etc.
All of the rocks on my layout were hand-carved from the same plaster as the rest of the scenery. I mix about 2 parts plaster to 1 water, apply when the batch starts to thicken, then chip away with an artist’s palette knife or putty knife.
Carving is useful for small outcrops, and is easy enough to practice. If you don’t like the results, chip them off or cover with more plaster and try again.
As you have found from the previous posters, the type of rock for your outcropping as well as the overall size will determine the method/s used. Many times, the rock finish is needed more for near vertical cuts, these tend to be much larger and need to carry along a considerable length of the cut. For outcroppings of granite, basalt and many forms of shale, I find that selecting the proper mold for casting will work better for me. Do remember that you need to account for casting thickness along w/ your scenery base for any clearances if nec. A method of placement where the casting will need to conform to an irregular base, is to place partially hardened plaster (hydrocal) molds and press/ hold in place for a few minutes. (you can feel the heat from the hardening plaster through the mold). A bit of fresh plaster buttered on the casting will help w/ bonding. Any excess oozing is not any trouble, as the surrounding area will generally need to be blended in w/ plaster, Scultamold or ground goop.
If you have a foam base, experiment on some scrap w/ carving techniques as this is another popular method. Sandstone and other sedimentary rock can be carved into the foam, blended, painted and weathered.
I tend to like working w/ dyed hydrocal and the scenery done needs to withstand some minor "abuse’ in a club setting. I work mostly in plaster and rubber rock. I have only carved a small bit of foam for this purpose, others here have mastered the look of various rock and will let them explain their techniques.
Castings of outcropping to work with the lower “cut” shale
I use Sculptamold (?) and just ‘carve’ the rock while it is soft and workable, usually about 30 minutes. I put it on with a standard putty knife and then do finer detailing with some clay modelling tools. Once painted it looks pretty good and you can keep working with the painting until you get what you want. These are a couple of areas that are finished on my layout.
Nice work on the Sculptamold, Bob. I started off doing lots of plaster castings to embed in it, but have gradually shifted so that I only use the plaster castings for highlights. Most is now Sculptamold, textured and painted. Here’s a few examples.
Almost all the “rock” on the newest part of the layout on the Cascade Branch is Sculptamold.
The piece behind the upper level track with all the trees is one long liftout. It would be crazy heavy with lots of plaster castings, but it only has a couple of small ones. The rest is all Sculptamold.
If I had used tradional methods with plaster, my liftout sections of scenery would be heavy. I used 1/4" sheet of plywood as a base. I clamped it in place, drilled holes and inserted dowels. This would make realigning the sections easier. I then layered foam, carved to shape and added thin plaster castings. You can make the castings thinner and lighter by only filling the molds halfway.
There was an article in MRR a couple of months ago about using tree bark for rock Outcroppings (that’s what I’m using but I’m trying to save some money and use more natural materials that I can get for free)
Having an understanding of geology helps, but if you are an observer of nature, that is great too. What you need to do is look an see what it really looks like in real life and try to imitate that.
Too often I see people just randomly stick plaster molds to the side of a hill and call it good. While that can be ok, it doesn’t always look realistic. Again look at real life - when you are driving - look at outcrops in road cuts. When I was a university student majoring in geology, our professors used to take us on field trips and one of the most popular things to do was they would stop at road cuts on the highway and we would all get out and look at them as a learning tool.
This is a good reason to use foam, and then carve it to the desired shape. While I strongly prefer not to use foam under the track as it doens’t hold nails or spikes, for scenery it makes a great deal of sense.
Thanks for all the replies. Great info and ideas. I started to “collect” rocks but figured it would get too heavy. My layout is only 9’x6’ so I am going to to use some of the ideas mentioned. Great pics of rocks and layouts too!
I had good luck making a curved rock cut (about 2’ long and up to 7" high), using crumpled aluminium foil and Sculptamold over a foam base. After putting the Sulptamold in the mold I let it set for a little while, then applied it to the verticle surface. Left the foil on for awhile, then removed. The wall was still soft enough to break off unneeded sections and place them elsewhere. I could also make more pieces to expand or fill in as necessary.
A little over a year ago I was told I had multi myaloma so between four weeks in the hospital and running to treatment twice a week I really haven’t had time to do anything on the layout. The mountains are about seven years old
First picture is wadded news paper with hydra cal cloth over it.
For carving foam I use a faleting knife and keep it very sharp with a fine stone. Cut in what you want to remove and flick the foam out. On a road cut I HC the casting to a straight wall of foam Filled in some around them with HC, shaved the front flat and then ran a hack saw straight up and down to simulate drill holes from the blasting.
Next is carved foam also, which I like much better.
If you had a chance to look at the mountains around Denver you will notice that the rock is slanted and this is true in several places.
The river wall above is also carved.
next is foam. This section is before I added 8 foot to the layout. Here I used some small rock castings and smeered wet hydro cal around the castings.
