Sometimes I find perfect natural stones and stone slabs but usually it is near impossible to find the perfect one and it is easier to craft one from flagstone. Flagstone is easy to find and suppliers abound, most will sell by the lb., so you can pick your rough slab piece from a pile or crate and get away for 20 bucks or less. There are a million names for various flagstones and they shift colloquially—some of the stones I have used are Colorado Rose, Birchwood Brown, Blue stone, sandstone, slate and granite. Basically there is the super hard, like quartzite and granite (igneous rock) and the softer stones like slate and bluestone (mostly metamorphic rock) both I work differently. The hard stuff is difficult to saw cut and takes a lot of time. It is also pretty brittle so I have to be careful not to fracture it when working the edges. Sometimes edge snapping can be done with a large pipe wrench to good effect—other times diamond cutting followed by edge chipping with a chisel works best. Softer flagstone is a lot easier to work with. A drawback of softer stones is that they can break easier and are more prone to erode or crack over time and with exposure to freezing. That said I have had many slabs like this for decades and they are still sound and they are frozen solid every winter—I like their look so I use them. I have been working in my shop making a stone slab for a specific tree.
Witch Tree needs a slab--so I make one
- Thread starter crust
- Start date
First I consider my tree, a wild looking cedar named the Witch Tree. I nice oval would set me back 500 bucks or way more and my washer and drier just went out so the decision is made—for now. After some tape measuring and pondering I decide the size I want will be teardrop shaped 42” x 18”. It has to be strong and stable because the planting includes a heavy rock. It needs to be a darker stone. I opt for blue stone. The stone I get is sound and not full of fissures and big enough to scribe out my plan. It costs 17 bucks. I chalk out the outline, take it outside on a bench, set up a strong fan to blow on my work, don my dust mask and goggles and then take my handy 4-1/2 inch angle grinder loaded with a diamond blade and score off large pieces and then gently break them downward with my hands. Once done with the shape I work the edges. Blues stone is easy to work. I begin by placing my chisel perpendicular with the edge and placing it on a slightly downward angle and giving it a sharp strike. Nice flakes shear off mostly on the bottom side. Every once in a while I chip off some on the upper face. As I chisel I try to keep my work irregular and try to not get wild with force. Sometimes I come back with the angle grinder and work off material on the underside thinning it up more-the cuts won’t be visible. Once the edge is chiseled and all worked I come back with large nasty pliers and crunch and chip the edges ridding any evidence of saw marks.
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Once I am all done and happy with shape and finish I clean up the stone and blow it off well then wash the bottom thoroughly. I then, on the bottom, draw a good 2 inch wide pattern for a bearing point (foot) usually 4 inches in from the edges on a large slab. I mix up some Full-Flex Thin set (for adhering tile—high quality) fairly loose and make a 2 inch band over my pattern roughly keeping it level by eye a minimum of 1/4”. I then cut strips of fiber reinforcement and bed it into the thin set, overlapping the joints. I use mesh used in the construction of EFIS (Dryvit). Masonry supply houses and some box stores have this—it is MUCH stronger and better than standard masonry mesh tape. I let this dry overnight and follow up on top of this band with more thin set which has been enriched with some straight Portland and fine sand to make it harder. I shape the bands so they are about 1” with the intent to be leveled by inverting and smooth the edges and use a brush and some slurry to smooth everything. Don’t dilly-dally too long or it will get too hard. I lay some thin plastic over my bench and carefully invert the slab on to it and seat it firmly and evenly as if it were a giant tile. I then let this firm up for a few hours or more (depending) and then very carefully lift it up and roll it over and smooth any over-squeeze and glops off and make sure the edges against the slab are smooth and sealed nicely and the foot has no jagged edges. I then re-invert it back on the plastic and let it dry for a couple days. I rarely drill anything on a slab and if tie downs are needed I slit the surface with my grinder or drill shallow holes and epoxy in wires. In the case of the Witch Tree, I will need to be prepared and during transplanting I will have to craft props out of stones and either epoxy or cement them in.
I hope this is helpful to all you folks out there needing a slab to plant.
I hope this is helpful to all you folks out there needing a slab to plant.
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sorce
Nonsense Rascal
Sure is.
Sorce
Sorce
Smoke
Ignore-Amus
Nice slab. I was hoping to see it planted. When will that happen?
also..... everyone needs just a box named "tape".
also..... everyone needs just a box named "tape".
Cadillactaste
Neagari Gal
Thanks for sharing...and explaining the differences in stone so one gets the harder material.
Looking forward to seeing it planted.
Looking forward to seeing it planted.
eferguson1974
Chumono
The slabs are great. But I love that tree! Hope we get to see them together when your "done". Thanks for sharing both.
Its 9 below zero right now--no TP anytime soon!
Smoke
Ignore-Amus
Oh...I forget that some places get snow. Will look forward to seeing this in a few months. Was that cedar growing in a rock pocket or on a rock?
Kind of on a rock--it is not a tree from the mountains.
Cadillactaste
Neagari Gal
Been there done that...though not this winter. Stay warm...brrrr.
ColinFraser
Masterpiece
Wicked tree; thanks for sharing! I too am looking forward to seeing it on the slab.
Potawatomi13
Imperial Masterpiece
Very nice tree and great information. Abounding inspiration and information.
Many condolences for BRRRRR
weather!
Many condolences for BRRRRR weather!
M. Frary
Bonsai Godzilla
You find these is swampland or more on dry ground.
I ask because I see more beat up and bent ones on higher ground. I found a few in a quarry that were growing low to the ground. And almost all of the cedars that grow in swamps here grow fairly straight and fast because if they don't the deer eat them.
Tieball
Masterpiece
Yes! That is a witch tree for sure. I'm looking forward to seeing the next finishing stages. Take some photos of the potting process....it didn't sound right to say - the slabbing process. I like to know more about how you build the walls (I think that's the right word...walls) to contain the soil and prevent water and weather erosion of the soil. Will there be walls?
This is related: Is the soil mix you plan to use on the slab very different than what is used in a bonsai pot? I am wondering about the whole drainage process after watering.
Thanks for the how-to instruction. Very informative.
This is related: Is the soil mix you plan to use on the slab very different than what is used in a bonsai pot? I am wondering about the whole drainage process after watering.
Thanks for the how-to instruction. Very informative.
mattspinniken
Omono
Crust thanks for taking the time to put this together, it's posts like this that make this website.
This is actually exactly what I needed. I have tried to do this but the edge would still end up being to thick, I think the angle grinder will really help. I also like the way you make the footing.
Excited to give this a try, or rather, a few tries. That is a special Cedar by the way!
This is actually exactly what I needed. I have tried to do this but the edge would still end up being to thick, I think the angle grinder will really help. I also like the way you make the footing.
Excited to give this a try, or rather, a few tries. That is a special Cedar by the way!
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Cypress187
Masterpiece
Very cool tree.
JudyB
Queen of the Nuts
GReat post! I too would like to know if you use a different soil mix on slabs. I've never been brave enough to try one... This tree looks like a natural for a slab, see how high she flys...
Geo
Chumono
Ditto on all the above, Wonderful tree!
