Dear Mirai family,
I am looking into making rock plantings and would like some tips on making a vertical stone, like Jan Culeck. i hear he uses plastic composite to make his stones. Any tips/ methods of making stone would be wonderful. thank you.
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I have no actual experience with this, but from having seen a few videos over the years and done a moderate amount of fiberglass and carbon fiber composite work I thought I would comment to see if that prompted someone with experience.
Most seem to be made by creating a basic structure from wire mesh. If the structure is large, it may have some larger diameter steel wire to provide more support. Metal window screen is fairly easy to deform and can be folded/bent to near final shape with minimal cutting. However, it is not very strong and will probably require additional support. I would suggest 8 wire per inch (3 per cm) wire mesh as a stronger alternative that is reasonable to work.
I am guessing that most are covered with polymer concrete - Polymer concrete - Wikipedia although the cheaper method is to use standard concrete mortar. The polymer concrete is much stronger than standard mortar. You will want a version designed for small repairs since the aggregate will be sand and not larger pebbles.
I would start with a small, relatively flat project. Make sure to wear appropriate personal protective equipment (PPE). Disposable gloves (I prefer nitrile) and safety glasses are the minimum - have extra gloves handy. Apron or old clothes are very useful since you will undoubtably get some on you. I suggest a chemical respirator for the urea formaldehyde and polyester based versions - I have not found it necessary for epoxy based with reasonable ventilation.
Good luck
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In the same light as Marty I am not an expert but made some non traditional pots-slabs basically following the process described above. I use a cement with a huge amount of fiber mesh in it and the key is thin layers building up to your desired thickness. I use chicken wire or some metal wire as a supporting form. Included some pics at first layer step where you can see metal mesh wiring and finished pic.
One idea I am going to play with when the weather warms is using expanding spray foam either as a casting mold or possibly as a base form since it’s weather proof and lightweight.
I have searched for a while about Jan’s process and come up empty so hopefully you have better luck or start you own and share with us when you make something awesome, your way!
Erik shares a good amount of his process.
Joe’s comment sparked the comment that you could sculpt the form from urethane foam and use the cement to cover it. You could even make the first layers from fiberglass for strength. The foam can be removed by a combination of routing out with a Foredam or similar tool and acetone to dissolve the remains or hard to get corners.
I used this method to make a 12" diameter nose cone for one of my rockets. I had the nose cone tip down on ground between my legs and was using my Makita to remove the bulk foam when I lost my grip on the Makita. Nothing like having a 25,000 rpm grinder bouncing around between your legs to get the blood flowing. I made sure the plug as very easy to reach when I came back to the effort the following day.
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Here is example of a carved foam scaffolding
He lays out every step.
I am personally going to try it with spray foam I used for my pond waterfall. Mainly because of the irregular shapes spray foam makes. So the process will be addictive instead of reductive (carving )in the building process.
Not sure if it is the same material (urethane foam), Marty probably knows the difference and trade offs?
https://bonsaibark.com/2018/12/30/bonsai-on-a-man-made-rock-from-scratch/
The spray foam is normally polyurethane and is soluble in acetone and several other solvents. However, it tends to swell a bit as is starts to dissolve. The pink rigid foam I have worked with and shown in the video above is polystyrene which is primarily soluble in acetone and quickly turns to mush. Sorry about my listing the wrong polymer originally.
I also have little experience making faux stone.
I think as is the case for most artistic projects the best way is to just start making things and see what happens.
I did have a phase when I was a bit obsessed making artistic concrete surfaces including inducing mixing iron pigments which over time rust leaving diffuse color pigmentation. The addition of various natural stone material can increase interest if surfaces are cut.
Another concepts I have worked with is creating shape and texture in moist sand then pouring a thin coat of (material of choice) to create a landscape. I required us to think in reverse as deeper holes create higher elevations in the imprint. The sand texture can also be a good starting place.
My newest projects will be primarily based on building larger structures using smaller pieces of various rock.
I purchased the material but have not yet tried making a container using layers of slate. My inspiration came from bonsai-shinshi YouTube video. I find browsing local rock corry? Lapidary? Or stone yard? to be great inspiration. Sometimes we find rocks that are almost ready to go. It’s also good to have a reasonable rock collection when the desire to do ROR compositions. Better to have some quality material on hand when the moment of inspiration strikes.
Happy growing ,
Mats Hagstrom
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Marty for what it’s worth and it was only a single project but I was able to curb the swelling but preserve the random interest in the spray foam by sprinkling Epson salt slowly over the spray foam while it is beginning to expand. I don’t know enough to understand what is happening at the chemical level that caused this but it was a happy accident that became a technique for my waterfall. I can’t say it’s repeatable at this point but it would be a decent point of trying if one was to go this avenue. I will update in a few months when I start exploring.