TIME: Once the materials are assembled it will take the average person about an hour to mix and cast the hypertufa into its molds, and then about a week for the mixture to cure (longer cure times will make for a stronger structure-- the industry standard is 28 days). Creating the molds can take as little as an hour or two if you have the necessary materials and tools on hand and have a well-organized sense of what you want to accomplish and how to make it happen. This Instructable should help with that.
TOOLS: This project requires no specialty tools or materials, and as long as the appropriate precautions are observed regarding the use of Portland cement, is not hazardous.
To make the hypertufa mix:
*Play sand, 2 qts., such as THIS
*Portland cement, 1 qt., like THIS (you do not want "concrete", or "mason mix", or "mortar mix", or "pronto mix", or "stucco"-- you want plain, simple, basic Type I Portland cement)
*Peat moss, 1 qt. (note that many commercially available peat moss is sold with Miracle Gro® or some such fertilizer added-- this fertilizer with compromise your hypertufa and is undesirable. You should acquire peat moss without added fertilizer, or use another plant-based additive like shredded cardboard or even shredded paper. If you accidentally buy some peat moss with fertilizer, you can also rinse it well before use to wash away most of the fertilizer, though you cannot mix it with the other dry ingredients until it itself is dry again and since peat moss is built to retain moisture, this can take some time)
*Perlite, 2 qts., such as THIS (substitute same amount of vermiculite-- in either case again make sure it does NOT include added fertilizer like Miracle Gro®)
*If you live in a climate that has winter freezing temperatures, you will also need about 1 sq. foot of shredded fiberglass sheet fabric
*Tap water, 2-3 cups
*Two large plastic mixing tubs (one for mixing the hypertufa, the other for dumping the dry ingredients into and back out of as you prepare it)
*Strong rubber gloves (I like to use "Bluettes"), filter mask a good idea too
*For clean-up, I have read about though not yet tried a product called Mean Klean which is a concrete and mortar dissolver composed mostly of eco-friendly and surprisingly effective yet non-toxic glycolic acid. It is inexpensive and readily available.
To make the casting forms:
*Scrap wood pieces of various sizes & thicknesses; I used some discarded painting frames made of easily-sawed pine and some pressboard from a discarded shelving unit.
*Glue (wood glue will work for most purposes but any strong contact cement will also do. What I had on hand was a product called E-6000 by Eclectic Products, Inc. (available from Michael's, click HERE) which they advertise as “industrial strength adhesive.” I don’t know if I would go that far, but it's pretty strong.)
*Kitchen plastic wrap, one roll; alternatively, you may use a sheet of "painter's plastic". Husky's Painter's Plastic (available from HomeDepot and viewable HERE) is wonderfully thin and though it punctures rather easily, it works very well for preserving water in hypertufa mix (though a 400-foot roll is much more than you will need for this project)
*Large plastic garbage bags, pref. puncture-resistant or heavy-duty, 3-4, such as THESE
*Various forms (bucket, plastic planter, lampshade, serving dishes, etc)
-Beveled glass tiles
To light the lantern:
*Ceramic light fixture (a Craftmade K212-O Porcelain One Piece Keyless Lamp Holder like TIHIS works well and costs under $2. Use a fixture without any switches or pull-chains, make certain that it is ceramic and not plastic
*Light bulb, pref. a compact fluorescent
*Copper wiring, 10'-20', and associated plug
*To make a paper liner, which is entirely optional: a sheet of rice paper, a Sharpie marker, some clear polyurethane-- see Step 4 for more details
Step 1: Before We Begin: Lantern Theory
A Japanese lantern or “to-ro” has a distinct style, and is composed of several distinct parts. The one you make may deviate from the style demonstrated here, and still be very Japanese in its format. A standard Japanese lantern like the one demonstrated here consists of the following elements, from top to bottom:
A&B..) Ho-ju or ho-shu ( lit. “jewel”) - The onion-shaped finial at the very top.
C.) Kasa (lit. “umbrella”) - A conical or pyramidal umbrella covering the fire box.
D.) Hibukuro (lit. “fire sack”) - The firebox.
E.) Chu-dai (lit. “central platform”) - The part on which the fire box rests.
F.) Sao (lit. “post”) - The supporting main post, often missing or replaced by legs.
There are various Buddhist meanings attributed to these items as well, but I will not review them here.
You need not follow my own design exactly, but if you want your own lantern to look like a Japanese one, here are some guidelines for constructing your forms:
The umbrella must be wider than the light box and its platform, and is often wider than the base as well. Lamps with very broad umbrellas are very attractive. The umbrella is often divided into panels like the light box, and often the number of panels matches and lines up.
The firebox must be narrower than the platform below it, and taller than it. It must also contain at least one and as many as six perforations/ windows. The firebox may also be made cylindrical. The most frequent arrangement of windows is six windows on six panels of a six-sided box, though a six sided box could also have only three windows that alternate with solid panels.
The platform must always be wider than the box itself and wider than the top of the base it rests on, though not wider than the umbrella, and must not be taller than the box (usually it is less than 1/4 the height of the box). Also, the basic shape of the platform frequently mirrors that of the box: if the box is square, the platform is also often square; a round box typically has a round platform; a hexagonal box, a hexagonal platform (this is not a hard and fast rule, and I do not follow it myself here). Note that the platform, however it is constructed, is usually made so that it's bottom side slants upward and outward from the top of the base.
The base: the base may be nothing more complicated than a pillar, although if a pillar, the pillar itself typically flares out at the bottom so as to keep it from easily tipping over. The pillar may be very short, even less than the overall height of the box and umbrella (for example, a lantern for a table-top) but the flaring rule still applies: if a pillar, the bottom is wider than its top. Pillars may also flare at their tops, but this is optional. Bases with legs will have between three and four legs, three being by far the most common if not the most stable (getting all four legs of a 4-leg lantern base to be the exact same length and therefore not wobble can be very difficult and the added stability is not always worth the effort, whereas a 3-legged base will never wobble).
WHAT IS HYPERTUFA?
Hypertufa is a a mixture of Portland cement and other materials which combine to produce a stone-like substance of exceptional durability while also weighing much less than standard poured cement and costing much less than stone to manufacture. It is often used to make garden planters– its use here is a variation on that theme, using hypertufa to make a garden object designed to house a light rather than make a planter to house a plant. Hypertufa tends to sag somewhat while it cures unless it is supported on all sides, so the use of molds is necessary. Properly mixed hypertufa, however, does a reasonably good job of holding its own shape as long as the scale is relatively small, though I would never build anything larger than a teacup with hypertufa without some kind of form on either the inside or the outside. Creating these forms is the first challenge of making a hypertufa Japanese garden lantern.