First attempt: DIY rocky caves

NinjaPenguin

AC Members
Feb 18, 2007
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Johannesburg, South Africa
Heres my first attempt at creating a 3d rocky ornamental cave structure for my GBR's. I wasn't sure how it was going to turn out so I didn't document it very well and missed out on photographing quite a few steps. I'm surprised how well it turned out though so here goes...

Started with 2 odd shaped pieces of polystyrene left over from the packaging we received our new washing machine in, glued them together using marine silicone sealant, carved out the basic rock shapes with a hacksaw blade then proceeded to melt and shape the structure using a candle flame. The result...

gbr_cave_01.jpg


Hunted all over for modellers concrete/quickcrete and in the end settled on external crack filler for the base compound. Purchased 3 colors of powdered water based paint to give me the range of browns I wanted: Burnt Sienna, Red Oxide and Black. Mixed the base compound as follows:

4 table spoons burnt sienna paint
2 cups crack filler
1 cup playpen sand for texture
1 table spoon coarse salt

Added enough warm water to mix up a smooth paste suitable for brushing onto the polystyrene "mold" - Looks almost flesh tone when wet and a pale beige when dry...

gbr_cave_02.jpg


24 hours later and the mixture has set - time for a second coating:

2 table spoons burn't sienna
2 table spoons red oxide
1 table spoon black
1 table spoon coarse salt
1 cup crack filler
1 cup playpen sand for texture

12 hours of baking in the sun and it's set rock solid. Time to mix some tones and dab on sparsely to create highlights and lowlights.

Highlights (added water and mix to watery paste)

1 spoon burnt sienna
1 spoon red oxide
1 spoon black
1 spoon crack filler

Lowlights (added water and mix to watery paste)

1 spoon burnt sienna
2 spoons red oxide
5 spoons black
1 spoon crack filler

Used a piece of mutton cloth dipped in the various tones of paint to apply the highlights and lowlights. It looks a lot darker when first applied but fades quite a bit when drying.

gbr_cave_03.jpg


Heres a closeup of the textures when dry...

gbr_cave_04.jpg


From the front...

gbr_cave_05.jpg


Next step will be to coat the whole thing in fibreglass resin which I suspect will darken the colors a bit. I'll wait a couple of days to make sure it's cured properly before attempting this...

How am I doing so far?
 
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That's pretty cool. Next time make the pix a little smaller please! :);)
 
Very good, I like the design. Be sure to cure the thing well otherwise your pH will take forever to come down to acceptable levels.

Thanks! :)

I'm planning on coating the whole thing in resin - that should stop any pH issues?

That's pretty cool. Next time make the pix a little smaller please! :);)

Done! better?
 
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