I am curious about rock castings.

[CrossTrack Trains]

I am new to model railroading, can someone explain rock castings to me?
Do you purchase or make these?

[Anonymous]

You can do either. Many vendors are happy to sell you the castings but they are very simple to make, using easy to make rubber molds. Usually a two part rubber that you mix per instructions and apply to the "model," in this case an interesting rock fragment or something with the texture & look of rocks, perhaps a coarse piece of bark or broken bits of ceiling tiles.

Most hobby suppliers sell the latex or silicone rubber for molds. You then mix your casting material & pour it into the mold. Some materials are hydrocal and other plasters, Sculptamold or two-part plastic.

Wayne

[mondotrains]

Hi,
Wayne offered some good suggestions but if you're new to the hobby, I wouldn't spend my time trying to make rock molds because the rubber latex is kind of expensive and for around $6.00 each, you can buy Woodland Scenic's rock molds which I personally use. They make around 8 different molds but you don't need them all. I use Plaster of Paris available, at any hardware or home improvement store. Woodland Scenics also makes great stains for coloring the plaster to look like various kinds of rock. I use the grayer shade which makes my castings look like granite. I thin it a lot with water so it doesn't make the rocks look like they have been painted.

Hope this helps.
Mondo

[Anonymous]

If you have a club or know other modelrailroaders try to borrow the molds, thats what we did ! The same ten molds passed through like four hands. Then all you have to buy is plaster.

[Anonymous]

Hi,
You can buy them at your local hobby shop. The rubber molds made by Woodland Scenics, a great producer of scenery products, are the ones I use.
You can pour plaster into them and let them set. Then you can add them to your layout. You can buy a Landscaping Coloring Kit from Woodland Scenics so you can learn to color rock castings[:)] I really hope I helped.

Plus, if your a new modeler, a good tip is read. Buy some modeling books from your hobby shop. You can learn so much.

Good Luck,
Dan

[jwar]

There is another type of rock casting. Called Geodesic Foam, using larger molds and applying two part resins, very fine detailing and coloring them is a different method. They cure in about thirty minits or so, with a hard surface that resist damage. The down side is the expense of which was worth the effort to me as visitors are amazed at the detail. for more info look at the site..www.bragdonent.com

Have a great day and welcome to the forum...John

[Anonymous]

QUOTE: Originally posted by jwar

There is another type of rock casting. Called Geodesic Foam, using larger molds and applying two part resins, very fine detailing and coloring them is a different method. They cure in about thirty minits or so, with a hard surface that resist damage. The down side is the expense of which was worth the effort to me as visitors are amazed at the detail. for more info look at the site..www.bragdonent.com

jwar: You're right, their products are very expensive but like most other stuff simply repackaged for model railroad use, t wo part resins and foams are available through plastics suppliers at a reasonable cost.

Wayne

[MAbruce]

I've used heavy duty Aluminum foil. Find a tree with a deep bark pattern (or even rocks) and press the foil into it to transfer the impression. Spray with simple cooking oil and fill with your favorite plaster. Makes a good rock wall.

I’ve also crumpled up the foil, carefully pulled it out (not too much so you save the pattern), and pressed it onto some wet plaster I applied right onto the layout. Wait until it sets and carefully remove. I’d also apply cooking oil spray before you set it into the plaster.

[dehusman]

To add to MABruce's technique, you can crumple heavy duty aluminum foil and then unfold it in a rough bumpy shape, mix a thick, pancake batter consistency plaster and pour it on the foil. Then slap it on the area you want the rocks and let it set.

You can apply cooking oil if you want, I've never had that much problem pulling the foil off the plaster, as long as I do it fairly soon after it's set. If you do use oil, just make sure it won't affect your ability to paint the rocks afterwards.

Dave H.

[Anonymous]

Rock Mold list from Bragdon Enterprises
Bragdon Home Page

[Anonymous]

I went for a wander around the neighbourhood until I found a rock in a garden with a really nice texture full of tiny cracks and striations. I spoke to the owner and explained that I would like to mould a copy of it for my model railway. He was intrigued by the idea and happily gave his permission.
With a tin of liquid latex rubber and a VERY cheap 2 inch brush, I painted a layer of rubber onto the rock, let it dry and then did another. While it was still tacky I covered the latex with a J-cloth (a porous type of cloth used in cleaning) and glued it to the other layers with more latex. When I had built up several layers and it looked strong enough, I peeled it off and took it home to play with! I have made several excellent cliff faces with it and lent it to several friends in my club for their scenery work.
Choosing a real rock as a mould can give extremely authentic looking cliff faces. When the final plaster moulds were painted with water colours, they looked stunning.
It's a lot of fun! Have a go!

[ericsp]

Just don't cast them through a window.[;)]

[trainwomen]

G'day from Australia. I have used quite a few of the methods of casting rocks and find all of them useful. I have some of the Woodland scenics moulds. I have also made my own using latex - very useful for making large rocky areas - some of my rocks are 1ft x 2ft. I use casting plaster in 20kg bags (much cheaper purchased this way). I also like to put mounds of plaster onto my layout and just carve the rock shapes with a wood chisel just as the plaster is going off. Sometimes I even use real rock. It can be a bit heavy but it is useful. I use a shale type rock with beautiful contours. The small broken bits are used as tallus - looks perfect and costs nothing. If you are going to make your own moulds place some reinforcing material between the layers of latex, particularly if you are making large moulds. I use Wettex dish cloths between every second layer and it adds a lot of strength to the finished mould. I have used some of my large moulds 30 to 40 times with no problems. Have fun and don't be afraid to experiment.
Regards from downunder.
Chris.

[Fergmiester]

I'm trying something completely different. I'm using wrapping paper and insulation foam.



On the right is Hallmark tin foil paper backed wrapping paper that has been primed with white primer and then painted with several washes. As for the pattern I rolled it up and then squeezed it hard and then gently unwrapped it. I did this twice. I then put a thin coat of foam in a can on the back of it and put it in place. You will have to check on it for a couple of hours afterwards as the foam will continue to expand and will have to be pushed back into position.



This second method uses packing paper painted with shellac and white primer. colours to follow. Again it has been backed with foam in a can insulation.

All I have to do is add fauna to dress it up and naturalize it.

Fergie