# Fake Rock Techniques



## ggazonas (May 11, 2008)

So I have been making some fake rocks using extruded polystyrene and hydrostone. The hydrostone is great but I need to texture it so it looks more like a real rock. So does anyone have a technique they know of that you can use to get that rock like texture and look, after pouring the hydrostone. 
I am aware you can use molds but I haven't been able to locate anything I could use yet and I don't want to make a mold.
One thing I was going to try was to mix sand in with the hydrostone when I pour it.
This is my first fake rock wall so I am trying some different things till I find a technique that works, so hopefully I can get some ideas from anyone who has done this before


Thanks 

George

BTW I will post images of the construction next week


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## Julio (Oct 8, 2007)

Hey George,
one of the things you can do is use a corse sponge after applying a nice thick layer to give it taht nice pourous look to it if you don't want that smooth finish on it, you can also incorporate gravel or sand into thecememnet mix.


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## carola1155 (Sep 10, 2007)

I would recommend not using too large of a grain of sand... as sometimes this just makes them looking like blobs of like sidewalk concrete (i dont know how else to describe it).

Also, acrylic paint washing helps give it a nice weathered look, check out the thread by Melas to see a good example of that

hope that helps!


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## ggazonas (May 11, 2008)

Thanks Julio I'll try that this weekend. . Hydrostone is a great product but it does dry awfully smooth. I'm gonna try sand first and see what happens. This is all expeimental right now.


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## melas (Oct 24, 2007)

Be sure to post your results (good & bad) so that we can all benefit from your experience! Good luck!


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## ggazonas (May 11, 2008)

How to Make Fake Rocks with Concrete (with pictures) - wikiHow

I happened to just stubble upon this and thought it would be helpful to myself and others


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## bellerophon (Sep 18, 2006)

Good to know. I'll be attempting to make a rather large cave entrace theme viv for some theloderma cortical using hydrostone.


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## ggazonas (May 11, 2008)

I think hydrostone is a great product once you get use to using it. I mix it so the mixture is watery because it sets up real fast. I found mixture small amounts at a time to be efficient for my use since it hardens in less than an 45 minutes maybe less. I usually just pour the entire mixture on the foam structure and move it around from their. It has an odd state where its is liquidy and then become solid. It sort of reminds me of lava flowing when I pour it on the forms. I just need to find a way to texture it to my liking.

Good luck with your wall.


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## boyaminalnurse (May 7, 2008)

I dont want to go off subject, but does anyone know of any local stores that carry hydrostone? Maybe lowes or HD, I have been looking and would prefer to buy locally due to shipping costs. Would like to spend my shipping costs on plants and such from vendors from here. Thanks 

Marshall


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## melas (Oct 24, 2007)

I'm guessing texture mats would work on hydrostone . . . I'd also think you want to use a release agent as well

California Rocks Texture Mats

edit: be sure to check out the tree stump/log mats too! sweet!


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## ggazonas (May 11, 2008)

boyaminalnurse said:


> I dont want to go off subject, but does anyone know of any local stores that carry hydrostone? Maybe lowes or HD, I have been looking and would prefer to buy locally due to shipping costs. Would like to spend my shipping costs on plants and such from vendors from here. Thanks
> 
> Marshall


if you go on this site it has a list of distributors or you can buy online. I am fortunate enough to have a dealer and I was able to purchase 100lbs for 36$

Gypsumsolutions.com - Brands


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## jpstod (Sep 8, 2005)

You can usually find Hydrostone in small amounts at any hobby store that sells Model Railroad supplies.

I know my local Micheal's and Hobby Lobby Does..While your there look into the Rubber Molds for casting also..


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## boyaminalnurse (May 7, 2008)

Called michaels and they said no. But I did get into contact with the sales rep for ca so she is gonna see what she can do for me. Keeping my fingers crossed.


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## parkanz2 (Sep 25, 2008)

Wouldn't pretty much any gypsum cement work? Or is there some reason that hydrostone is special? Just wondering, thanks!


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