Shaping and Painting Rocks?

[paulp]

I'm currently building a layout for my 6 year old son. I'm using a rigid foam insulation (kingspan) to shape rockfaces where I've built raised track sections

I intend to glue the foam (2inches thick) to the face of the raised sections, then sculpt the face with a craft knife, seal it, and paint it and apply greenery.

I have two questions.

Firstly my attempts at sculpting look fake, they are too even, and the rocks seem way too large. How do you sculpt realistic rock?

Secondly I know when it comes to painting I'll probably end up with a flat grey looking rock. What colour best suits rock, and whats the best method for getting a natural look?

Thanks in advance

[nalmeida]

Hi there Paul, I've been using a method that I learned trough the net and I think it gives satisfatory results, here is an example:



The method used is casting the rocks using woodland scenic molds, one or two are enough since you can break them in many pieces and "reconstruct" the wall in the way you like it best.
For painting I use three colours, raw sienna, raw umber and burnt sienna, I make washes with these three colours and paint the rocks in several layers. I use the darker tone in the recessed parts and the clear ones on the extruded parts, in the end you should use the middle tone on everything and use some weathering pastels to add details. All that said I should make a illustrated tutorial about this. If you need any further help just ask.

[loggeron30]

Hi Paul,
As Nelson said, I think molds are the way to go. I don't know how much "rock wall" you plan to make but I'll give you a little detail on what I have. I have six molds from Bragdon and I built a rock wall for a friend's G-scale layout that is 14' in lenth and 4" in height using the same molds at alternating locations. You have got to stare at the wall for sometime before you see any reproduction. I also did the same thing that Nelson mentioned about breaking off castings and replanting them too.
One final note that I think most of us fail at one point. Most rock is darker then we tend to model. I would suggest that you gather a few large samples and bring them indoors to compare with the basic formula Nelson suggested.
Ken

[paulp]

Thanks for the advice, I've read up a bit more, and I think that my original plan of shaping the foam will not work.

I'll either get some rock moulds as you both advise, or cover the foam in plaster and hand shape it following a procedure I read about on here.