fake boulder techniques

[mtbikernate]

I'm working on a cache in a fake boulder. Not a fake fist-sized rock. I'm talking 5gal bucket inside a much larger object. I got the form finished today. No pictures (intentionally) because I'm aware that some locals do read these forums and I don't want to tip them off. Still, I'd like to share a bit.

 

This isn't a cheap hide, let me start off by saying that much.

 

First, I bought a bunch of galvanized hardware cloth (steel mesh, found in Lawn & Garden next to the chicken wire).

 

Step 1:

I cut out sections and used 16ga wire to tie them together into the rough shape I wanted. It's pretty flimsy at this point.

 

Step 2:

decide how the bucket will be accessed and accommodate such access (vital trade secret)

 

Step 3:

Line the interior of the mesh with contractor trash bags or plastic drop cloth or something similar.

 

Step 4:

Insert bucket, fill around bucket with filler materials. I used some scrap PVC pipe to make a more rigid interior structure to give the form a more solid shape. I planned to use expanding foam insulation, but I wanted to make the boulder heavier so I put a bunch of scrap lumber and used crumpled newspapers to fill large voids. I wound up using 14 cans of expanding foam insulation anyway to seal things off and make it more solid.

 

Step 5:

I only just finished step 4, so I haven't worked out all the details here. But, you want to use the material of your choice on the exterior to make it look like a rock. Some folks suggested hypertufa to me, and it remains an option depending on whether I can source all the materials locally or not. The mesh form of the boulder will give strength to the exterior coating. I plan to use powdered concrete color to give it a more natural local rock color and I'm considering making a texture mat from some mold builder latex.

 

I WILL post pictures when it's finished because it will be obvious the hide is inside a fake boulder, but I plan to make it difficult to find where to access the 5gal bucket.

[+sword fern]

Cool! What's the D/T rating?

[mtbikernate]

Cool! What's the D/T rating?

 

Haven't decided yet. Terrain will be low because access will be pretty easy (I anticipate this thing being heavy enough to require heavy equipment to move once it's finished, so I'll have to put the final layer on in place).

 

Difficulty will depend on how good I am at obscuring the bucket access. I am shooting for somewhere in the 3-4 range.

 

Once someone gets FTF I'll put some pics in the CCC thread.

[+dirt_empire]

Coolness!

[+A & J Tooling]

If using a concrete stain, could I suggest you splash it on when wet? Much more natural. And I do mean splash. Just wet the brush and slap or swipe the brush across it.

 

I love your idea. Make sure you place it where it can't roll down hill. Nothing worse then someone getting crushed by your homemade boulder.

[mtbikernate]

If using a concrete stain, could I suggest you splash it on when wet? Much more natural. And I do mean splash. Just wet the brush and slap or swipe the brush across it.

 

I love your idea. Make sure you place it where it can't roll down hill. Nothing worse then someone getting crushed by your homemade boulder.

 

I was planning to use powdered stain. Thinking of mixing one shade into the material I use and then using another to toss onto the surface to provide the color variation.

 

It won't roll. I made it with a very well-defined flat bottom so I can rake away any debris or vegetation from the ground that will then be used to hide the bottom edge. Plus, the hide location is flat enough that there will be no rolling downhill. I highly doubt anyone will be able to tip it over on its side, anyway.