Ok for those of you that have done this I need some help and suggestions. I am wanting to make a wall that looks like rock. I have searched on the site here but cant get it to ull up what I want. So…that being said could Ya’ll help me out and point me int the right direction or post some pictures. Thanks… 
Did you see this?
http://largescalecentral.com/forums/topic/25753/quot-the-original-quot-kittom-lumber-co
Travis,
What kind of rock are you looking to do. Doc Tom did a great sand stone in the thread David linked. If your looking for more of a blasted granite look then you can do it the way I did in my Challenge build, the discussion starts here http://largescalecentral.com/forums/topic/26380/devon-sinsley-mik-2017-dunakin-pass-snow-shed?page=2. I also posted a little tutorial on an accident I had that turned out to be a great looking rock in my opinion http://largescalecentral.com/forums/topic/26563/foam-rock-tutorial. This technique could make some cool lava or basalt type formations.
The real source for this in my opinion is the aquarium trade. That’s where I got my ideas and tricks. Look on Youtube at DIY foam aquarium inserts. https://www.youtube.com/results?search_query=DIY+foam+aquraium+inserts
Yeah, Travis…what kind of rock wall are you looking to model? Man-made wall? Natural wall? Maybe if you could give us a picture of what you have in mind, somebody’s bound to be able to suggest something.
Basically a retaining type wall that will sit behind the waterwheel and off along the side part way. A stone pattern or block. Would like to have a different pattern than what we have already used in the challenge…
You could always carve your stone/brick pattern into some blue or pink foam with the tip of a soldering iron. Then texture the face by pressing an irregular shape into the foam (a real rock works well). Afterwords, add some paint and weathering.
-Kevin.
Hmm,
Interesting assignment Travis. Since we saw so many different uses of stone. Something that i have not seen done is basalt column rock. 
Basalt columns come in all sorts of sizes so you can make as few or as many as you want and as vertical as you want which means more or less revealed (read, how much needs to be carved). They are uniform (they are actually crystalline structures) in size and shape. For a small reveal I think they could be easy to create in foam. But they are volcanic also and don’t just fit into any landscape. Where I live the are all over.
That would be a natural formation of course, sounds like oyu looking for a man made stone structure. What about something like this It would be easy to create with a soldering iron.
Mr. Dieseldude: I insist that you stop signing your posts with the obviously fictitious name “Kevin”; whom do you think you’re kidding?
Travis, up in Central City and Blackhawk here in the mountains they have lots of different rock retaining walls and I think I have some pictures. I’ll try to find some tonight.
Dry set or wet? Devon’s 2nd pic shows both…
For Dry set you’ll want knife cuts for lines and with wet set you can use a wood burning tool to melt mortar lines and back fill with the color of your choice.
The surface can be rough, carved or smooth… how deep are the company’s pockets? I feel that gouging and scraping will give a rougher surface than melting. Experiment on scrap.
I can’t wait to see your solution, I feel lucky to be in with so many fine crafts folks…
John
Oh hey I just remembered something. Another approach that is actually cheaper and just about as easy to work with. Consider sheet rock. I used to make some pretty cool rocks and rock walls from bits of sheet rock. You take off the white paper layer (its easier than the grey side) and then carve your rock face into it. When i was doing HO and N i used this technique a lot as well. I was big into casting plaster rocks and then got onto the idea of making rocks with sheet rock. I made a block tunnel portal that way and it came out great. Large scale should be even easier. Just use what ever various tools to carve in the design.
But would sheet rock hold up outside?
good point Tom,
Wasn’t even thinking about that.
John Passaro said:
…
Travis, up in Central City and Blackhawk here in the mountains they have lots of different rock retaining walls and I think I have some pictures. I’ll try to find some tonight.
Travis, I couldn’t find the pictures of what I was looking for, but on the internet I did. These are pictures from Old Fall River Road in Rocky Mtn. Nat’l Park, a road I love for it’s beauty but also because I’ve sold tens of thousands of dollars worth of paintings of the scenes from this road, which is a good reason to like a place as I can think of. Anyway, the Park Service got tired of this happening:
So they made these:
Basically they’re wire cages filled with rock. I intend to use this method in my mountain yard in a couple of places. And the nice thing is you can use real rock found or crushed to scale size. Here’s a picture of what it looks like, again from the internet.
Just an option. I don’t know if they use these kind of retaining walls anywhere except in Colorado or not.
edit: obviously I know they use these kinds of constructions in other parts of the country, but they seem to be strictly decorative…out here they are actually functional.
That is something I have never seen modeled John. That would be a great project.
Also used as retaining walls for storm streams, reinforcement for regular washouts, and even laid on an angle to maintain water edges. Cheap and quick employment that holds up. This is in the Pa. and Md. area
they’re called gabions if I am not mistaken. We see them here in Idaho also. Some 1/4 hardware cloth and crushed gravel would make some nice representations. I would like to see this modeled. To late for my pike but it would be neat to see on a layout.
They use them for seawalls/ Rip Rap in New Brunswick Canada.
DieselDude mentioned using blue or pink foam board and a hot tip of a soldering gun to draw the mortar lines which works great.
I have used that technique to build a stone bridge with good results.
I have also used plastic trim boards and a dremel with a round tip on it to carve random lines then sanded the rough bits off then used multiple coats of paint to flavor. I have also used pressure treated wood with the same technique to create foundations on wooden buildings.
This is a plastic foundation base with a hardi backer board surround for an idea.
Happy RRing