Rock Spikes (Ecodefense)

Rock Spikes

Hard Rock vs. Heavy Metal: Quartz Tree Pins

Certain types of rock could well be the ideal type of anti-sawblade “pin” for planting in condemned trees. As with other types of monkeywrenching, proper materials and technique are essential.


Begin by obtaining copies of lapidary. magazines at a quality newsstand. Among these are Gems and Minerals and Lapidary Journal. Scan the ads for lapidary supply houses and supplies in large cities. For security reasons, select a business in a distant city. Make your equipment purchases in cash. Never leave your name or address.

In the magazine ads, look for either manufacturers or retailers of lapidary saws, particularly a type called a “trim” saw, used to cut small stones into precise sizes and shapes. This power tool handles a circular sawblade made of high grade steel core with a cutting edge impregnated with chips of industrial or human-made diamond. The smallest size, a six-inch blade, should be more than adequate. These circular sawblades are far better than band or wire saws for our purposes, as they will handle greater pressures. Make sure your trim saw has a vise for holding the stone during cutting. You will also want to pur-chase the recommended coolant, as it is essential that the sawblade’s bottom edge be immersed in this oil-based protective material. An extra blade or two can save you a return trip should you damage your first one while learning proper cutting technique. Trim saws vary in price from about $160 to $350, with good quality models averaging around $300. Diamond blades range in price from $20 to $45. The more costly types are thin blades for fine cutting with a minimum of material loss (important only for work with precious and semi-precious stones), so the lower priced general-purpose blades are what you want. Dulled or damaged blades can be repaired and re-surfaced by manufacturers, but don’t leave a name and address for investigators to trace to you.

Information on proper use of the trim saw can be found at a large public library in lapidary and jewelry-making books. Read and/or photocopy the information at the library. If you check out a book, you will leave a paper trail betraying your interest in this subject.

Following are some important rules for correct operation of a trim saw:

  1. Always put safety first. Wear safety glasses. Be patient while learning to use the saw.

  2. Don’t use long extension cords to power the saw as this will cause a loss of power through voltage drop.

  3. Maintain proper coolant levels. Otherwise you will quickly destroy an expensive blade.

  4. Make sure the surface of the rock you are cutting is at right angles to the blade. Cutting into an angled surface can create side pressures that bring about a wobble and rapidly wear out the blade.

  5. Slow down at the end of every cut to keep the rock from breaking and leaving a jagged spur protruding from the cut surface.

Stones can be cut into any elongated shape that will fit into the holes drilled into trees, generally not exceeding one inch in diameter. After cutting, clean the stone “pins” in warm water and dish soap. When finished, store them in a container to prevent accidental handling with bare hands (fingerprints!).

Rock Types

The large majority of rock types are not suitable for modification into “pins” simply because they are not hard enough to damage a sawmill blade. Quartz and related minerals are perhaps best. On the Mohs’ hardness scale (from one to ten), quartz rates a seven, making it harder than steel which ranks from 5.5 to 6.5 Furthermore, virtually anyone with outdoor experience will recognize quartz in the field. Quartz is found throughout most of the US.

Quartz comes in a variety of colors, from clear or milky white, to rose or red-dish, yellowish, and even blue gray in some gold-bearing regions. A good field test for rocks you think are quartz can be carried out with a small piece of glass. If the rock is quartz, it will scratch the glass. If it will not scratch glass, it is simply a quartz look-alike. Start with small quartz rocks until you know what your trim saw can handle. Proper use of the saw will permit a single diamond blade to cut thousands of square inches of quartz.

Lower Cost Alternatives

If the cost of procuring a trim saw is prohibitive, one can scour the area of quartz deposits for fragments or river-worn pieces small enough to insert into a one-inch hole. On the negative side, they may be difficult to load into the drilled hole and less likely to come into contact with a sawblade.

Smaller quartz gravel can be combined with cement to make a round pin of some value. First, roll-up heavy paper and glue it into tubes one-inch in diameter or a little less. Mix three parts gravel with one part cement and one and one-half parts sand. Add water, a little at a time, until the mix is wet but still very stiff. Next, load it into the tube a little at a time and use a dowel to tamp it into place, eliminating air bubbles. Wearing plastic gloves will protect your hands from the lime in the cement. Set your pins in a cool but moist place to cure. Ideal conditions are 70 degrees Fahrenheit and 80 percent relative humidity. Allow them to cure from three to six months for maximum strength. Finally, peel off the paper tube exterior and paint the pins with a coat of exterior latex paint to protect the concrete from deterioration. Make sure the concrete is never exposed to freezing temperatures while curing. Use pieces of quartz gravel as large as is feasible.

Still another low cost pin involves using large quartz gravel or cobbles in a matrix of a good quality resin epoxy available at hardware stores and lumber yards. Form it into pins in the same way you would with the concrete method. This can allow you to use larger quartz rock fragments with a better chance of impacting a blade. The paper can be soaked in water and gently scrubbed off once the epoxy has set-up properly.

Rock and concrete pins require the drilling of large-diameter holes in trees which are best done with a brace-and-bit. Use the techniques described earlier for drilling and disguising the presence of the pins. As with ceramic pins, setting rock and concrete pins is time consuming and you should not expect to set a great many in one working session. However, properly placed and disguised, such non-detectable pins should be a highly effective deterrent. Note: As always, avoid placing the pins in the lower three feet of the tree, where they can cause chain saw kickback, with the possibility of injury to the feller. After all, we’re in it to save trees, not hurt people.

— T. O. Hellenbach

Field Notes

  • You may be able to find granite cores from old mining operations in rock shops. These circular cores from drilling are ideal non-metallic spikes. They can also be found anywhere test drilling is done, particularly around mines, bridges, dams, and energy plants. Since this drilling is done in order to analyze the underlying rock strata, the core samples are often kept for reference. But since more drilling than necessary is usually done, there’s bound to be waste material lying around.

  • Any good geologist can fairly accurately pinpoint where rocks of particular types come from, so it might be a good idea not to collect rocks from your property or even nearby.

  • An effective mold for cement and rock spikes would be the pasteboard tubes inside rolls of toilet paper or paper towels. Another would be a section of PVC pipe. After drying, remove the pasteboard tube or pipe.

  • An indication that lumber barons are taking non-metallic spikes seriously comes from the Missoula Technology and Development Center News in June, 1990. It reported that a fluoroscope had been tested on logs for detecting ceramics and rocks embedded in them.

  • If you find the suggested methods of pinning with ceramic or rock too much work, try a less sophisticated method. Simply drill a hole, stuff it with gravel or cobbles, fill it with caulking, and plug with a wooden dowel. It is much quicker, simpler, and cheaper. While this may not completely ruin a sawblade, it sure as heck won’t do it any good!

  • Drive small rocks into the crevices of the bark. Tree-cutters hate hitting rocks imbedded in trees even more than nails, as rocks do more damage to saws; and rocks cannot be detected by metal detectors.

  • Large-Diameter Bits. Since 1” and 2” diameter holes required for some non-metallic tree “spikes” are generally out of the range possible with cordless electric drills, an old-fashioned hand brace is required. Several types of large-diameter bits are available. Long (12” and upwards) ship auger bits are good, though difficult to locate and quite expensive. Extra-wide auger bits are available at some well-stocked hardware stores and can be used with an extender for deep holes. Unfortunately, these extenders are hard to find for standard tapered-shank bits. Several models of “micro-dial” bits are available for holes up to 3” wide. These cost around $15 and allow the hole width to be adjusted to match the diameters of the pins used. If you can find a tapered-shank bit extender, use it with the standard-length (about 8”) auger bits. If you can’t find a tapered-shank auger bit, find a micro-dial bit with a square shank for a power drill. This may have to be special ordered; Irwin Tool Co. does make them. With this bit, you can use readily available power-drill bit extenders ($3 each, lengths up to 18”). The power-drill bit extenders do require a special set of jaws in the hand brace, but most newer models accommodate both square and ta-pered shanks anyway.

Avoid the temptation to use too long an extender. A total length of 18” (bit plus extender) is maximum; any more length will make your set-up too unwieldy. As always, stick to only the best tools and check second-hand stores first. With a little searching and luck, a set-up as described above can be had for as little as $15! And second-hand shops are the best low cost sources for hard-to-get items like tapered-shank extenders and extra-wide auger bits.

Remember, drilling holes in trees with a bit-and-brace is hard work. You will need to be in shape.

Maximum effectiveness of “super pins” might be achieved by sending a warning letter and a pin sample (so they will believe you!) after the spiking. This in itself may be enough to deter logging in the spiked area; if not, at least the mills will know precisely what is behind the destruction of their expensive blades and won’t make the same mistake again.

— The Phantom Driller

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