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[SG] Hypertufa

> I'll preface this by saying that I have used this mixture to make all
>sorts of garden containers from large rectangular planters to terra cotta
>looking pots to stepping stones. The life span is about 20 years; they
>don't chip or crack in the weather as does terra cotta.
>
> Recipe:
>
>1 part Portland cement
>1 part peat moss
>1 part sand, vermiculite or perlite (the latter two make lighter
>containers, etc.
>Enough water to make a consistency similar to modeling clay (you want it
>to stick together but not be soupy).
>
> Directions:
>
> Mix the dry ingredients together thoroughly first. Then slowly add water
>till you reach the desired consistency. Line your mold with plastic,
>preferably about 1 mil. Smooth the plastic as much as possible, but don't
>worry too much about folds and/or wrinkles--these will give your container
>character. Do not, however, allow really big folds and/or wrinkles as
>these can make a weak spot in your container. Molds can be anything from a
>bowl, dish pan, plastic pot to something free-form. For free-form molds,
>you can make a hole or shape in a pile of dirt or sand and put plastic
>over it or in it. For large containers, you can build a mold with extruded
>polystyerene foam insulation sheets, making and outside and an inside.
>
> Assuming you are making a smaller container, put a large glop of the
>mixture in the lined mold and work it up the sides. (This will remind you
>of kindergarden.) Make the sides and bottom at least an inch thick. If you
>live in a fairly mild climate (Zones 6 and up), you can make the sides an
>inch and a half to two inches thick and leave plants out in the containers
>year round. The roots will not freeze, especially if you protect the
>containers. Remember to push a hole in the bottom for drainage. You can
>widen the hole before the mixture completely dries or you can use a
>masonry dill.
>
> Once your happy with the thickness, shape, etc. cover the container with
>plastic and let it harden. This usually takes about 36 to 48 hours,
>depending on weather conditions. The higher the humidity and the colder,
>the longer it takes. When the containter is fairly hard (you can still
>barely make a scratch in it with your fingernail), carefully unmold it. At
>this stage, the container will be slightly shiny. You can rough it up
>gently with a wire brush. Then leave it to dry thoroughly--about a week,
>depending on the weather. If you keep it in a damp spot for awhile, it
>will grow moss.
>
>Caution: Portland cement contains lime. It will burn your lungs and eat
>your hands raw. Wear a mask and rubber gloves!
>
>Colors:
>
> Portland cement come is grey and white. Colorants are available in wet
>and dry powder forms. If you want good colors, use the white cement. If
>it's in dry powder form, add it to the cement only first and mix till you
>get the color something close to the color you want, then add the
>remaining ingredients and water. If you are using wet colorant, add it
>after you've achieved the consistency you want.
>
>Sand, Vermiculite or Perlite?
>
> Sand makes a heavy container, which may be okay for small containers or
>stepping stones. Vermiculite is my preferred choice. It blends well with
>the other ingedients and doesn't show in time. Perlite leaves little white
>pieces, which I don't care for.
>
>Added strength--particularly for large containers:
>
> Hardware cloth or poultry netting can be imbedded in the mixture or a
>product called Fibermesh can be added to the mixture when it's all mixed
>together. You only need a handful of the latter. Little fibers will stick
>out of the finished container and these can be removed with a blowtorch.
>
>To build a large container:
>
> Cut sheets of the polystyerene to desired widths, lengths, depths, etc.
>with a knife. Fasten the sides together with screws and put duct tape all
>around the sides. You don't really need to make a bottom. You can sit the
>form on plastic. Make another container of polystyerene that will fit
>inside the first one, leaving about an inch and a half to two inches of
>space between the two. Place one or two, depending on the size you have
>chosen, small cans on the plastic bottom. Pour in enough mixture to cover
>the bottom shape of your outside form. Place your inside form inside the
>outside form and fill the sides with the mixture, packing it down to
>eliminate air bubbles. Cover and let dry as you would a smaller container.
>
> For anything deeper than 15", you will need to build a mold. Otherwise,
>the mixture will have a tendency to slump down.
>
Floyd Rogers - Zone 5A           Butterfield Gardens
frogers@ix.netcom.com            Warrenville, Illinois
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