Thankyou to all respondents. I must apologize for incorrect data in my profile. I am in Australia but the registration page requires a valid ZIP code - not accepting Australian format ... I have started with cement sheets for 4 raised beds: 180 cm x 60 cm x 45 cm. They look great, 2 painted in bright orange and two closely immitating timber: woodgrain textured cement boards painted over with Timber Effects Jarra paint. For the first 2 raised beds I built a frame from treated pine (painted over to prevent toxicity). From this experience I learned that such a solid frame was an overkill in sturdiness and cost. For the next 2 beds I used a sort of a frame (corner poles) made from garden stakes produced by http://www.plasticrecyclers.com.au/stakes.htm After the materials are brought home, it takes less than an hour to build such a bed (frame, cutting sheets to size, painting and setting up) For these beds I used woodscrews to affix cement sheets to the frame. The sheets used for the first 2 beds were the thin DuraSheets (4.5 mm) from http://www.bgc.com.au/fibrecement/s_02/02_durasheet.html on a solid frame. Later I swiched to 7.5 mm DuraPlank (same source) fixed to the light frame. As to the containers (currently 3) - I am using 300 mm wide sheets of 9 mm thickness on the frame from recycled plastic. Two walls are glued to the frame (poles) and two walls and a floor are fixed with screws so that the container can be easily disassembled for root treatment or stowing away as a flat pack. I am much encouraged with your prevailing opinion that toxicity of fiber (fibre in Aus) cement sheets is not a major issue especially if they are painted over. I'll try to post photos later PM

Sorry guys - I've been 'away'. ;o) I think I answered some of these questions via email, but if I missed you & you need an answer, please ask again. I know I didn't answer Alice, so: You can buy small pieces of hardware cloth and insect screen at most good (real) hardware stores. If you have someone to make a frame from 1x4s for you, you can staple it to the bottom of the frame. You can sometimes find wire mesh waste-baskets & letter boxes (like for your in and out trays on your desk) at dollar stores or office supply stores/depts. They will be somewhat useful. Seed mixes need to A) be sterile B) hold enough water w/o being soggy C) hold LOTS of air. If you can find any material that isn't toxic and meets these three requirements, it will work well as a seed starter. I use screened Turface, then layer the seeds and cover them with about 1/4" of Turface fines. If you have really important seeds & want to get them off to a REALLY goods start, mix a fraction of chopped sphagnum moss (not peat) into the Turface & it will REALLY give the seedlings a boost. "My unscientific take is that depending on the temperatures and soil moisture, some things (mostly observed lettuce) germinate quickly but don't take off growing rapidly in a loose mix like Al's mix." I find the opposite. There is no substitute for a very well-aerated mix to promote rampant growth in seedlings. Aeration is a key consideration in EVERY commercial from-seed operation. From another thread, Les asked: "If you would so kind as to answer a couple of questions for me - will orchid bark work in your 5-1-1 mix? Also, what would be the best way to water? it should be very hard to over-water in your mix - right? How and when to fertilize and at what p.p.m.?" Orchid (fir) bark is generally too large and is uncomposted, but if it is ground fairly fine (1/16 - 3/16 is best) it will work. I usually use it in Water when plants need it - just before you think they will show signs of wilting. You need to water newly established plantings a little more often because roots are in the top part of the container, but once the planting is established & roots have colonized the soil mass, you can feel the soil at the drain most plants) and water when it feels dry. Alternately, stick a wick in the drain hole & water when the wick feels dry. You're right though; if the mix is made the way I make mine, it is very hard to over-water; but you CAN do it .... if you work hard enough at it. ;o) Fertilizing is difficult to advise on, unless I know what you're using. If a soluble product like MG or others, there are a number of ways to fertilize. You should base application rates & intervals on temperatures & how fast the plant is growing. If you fertilize at 1/4 recommended strength every other time or every third time you water, while the plant is growing strongly, you will be in good shape. Alternately, you can half the recommended dosage and interval suggested on the container, or fertilize according to directions. If you have more fertilizer questions,l follow the link I left below. Al

Hey guys, I'm liking that Elmers glue, and latex paint suggestion, cheap, and possibly just sitting in a can downstairs, IF, it's not a solid mass of dried up crap by now, paint, that is. I have had some projects that haven't cracked, BUT, some that have. I'd always heard that HYDRATION was key in having a finished project NOT crack, you know, to hydrate it long enough before taking it off and using it. I'm hoping that IF I can't use my old latex paint that is downstairs, IF it's all hard and non usable, AND, I hit up the local WM paint section, and buy some god ugly color that is REDUCED majorly, I'm HOPING that my Hypertufa project WON'T be showing streaks of the god ugly color through it. I want to make a hypertufa planter for succulents. I'm guessing the liming effect of the cement may make the paint color less likely to be bright or showy? I remember buying a small amount of "silica fume" years ago, and never using it, I wonder IF I can use that on this project OR would it be big waste of it, that I should use on a much more delicate project? Really, anyone who knows just what one would use "silica Fume" for, please tell me, I forget what I bought it for, and, if it goes bad quickly, I am sure it has been way too long to use it now. BTW, I have an OPENED BAG OF PORTLAND Cement, it's been open for a few years at least, can I still use it? I've seen cement sitting outside in a heap outside of a place that makes and sells concrete statues, surely sitting in my basement in a bag it's fine, right?

Accelerator - Ingredient added to increase hydration, shorten set and cure times. admix - Admixture. admixture - Generic term for non-bulk material added to 'tufa; also an abbreviation for acrylic bonding admixture, which increases strength while reducing moisture absorption in 'tufa. aggregate - Any dry bulk material added to 'tufa other than portland cement and sand. air entraining agent - ingredient added to 'tufa mix which captures miniature air bubbles during the mixing process, reducing the harmful effects of freeze-thaw cycles. alginate - One-time use mold-making material used primarily for body casting. armiture - "Skeleton" or support struture for a large 'tufa project. Bug holes - Small holes in castings caused by air bubbles. BRB - Be right back. BTW - By the way. Casting - End product of molding process. cement - See portland cement. chicken wire - A light galvanized wire fencing usually made with relatively large-sized hexagonal mesh. Can be layered around an armiture to hold 'tufa and strengthen structure. closed-cell foam - Hard, nonabsorbent foam. compressive strength - Ability of 'tufa to to withstand downward force or to sustain a heavy weight. concrete - A mix of portland cement, sand and water. The standard construction recipe calls for one part portland cement to three parts sand/rocks. concrete admix - See admixture. cure - Pprocess by which 'tufa hardens; dependent on sufficient hydration and temperature. DH - Dear Husband. DWT - Drywall tape. Efflorescence - Salts which leach out of 'tufa during the curing process. Faux bois - Imitation wood (French). form - Mold used for the setting an outside shape. Grot - Abbreviation for grotesque, which is a gargoyle which does not serve the purpose of a rainspout. Our grots serve as planters but have the same unusual attributes of a gargoyle. green - Uncured. GW - Garden Web. HWM - Hardware mesh, cloth. Used to reinforce larger 'tufa projects. hydration - Chemical reaction between water and portland cement. IMHO - In my honest opinion LOL - Laughing out loud. Model - Original piece (usually of artwork) used to make a mold. Mold - A rigid structure used to hold green 'tufa into a fixed position until it sets. See also postive mold, negative mold, mother mold. mortar - Variation of concrete used in masonry; does not contain rough aggregate. mother mold - Outer, often rough mold made of the back of a mold. Used to secure the mold during the casting process when it is made of fragile or flexible material. moulage - Reusable mold-making material used primarily for body casting. Negative mold - Casting of a model which is made to create a positive mold. Used when original model is fragile and requires the use of nondurable molding material. nylon fibers - Added to 'tufa add strength and cohesion. OMG - oh my gawd/garsh. Paper pulp - Shredded paper soaked in water and agitated; used in papercrete. papercrete - Variation of 'tufa consisting of paper pulp, portland cement and sand. perlite - Volcanic glass superheated to form a lightweight aggregate which can be used in 'tufa. Has a high moisture content. plasticizer - Ingredient added to 'tufa mix to increase workability. pop - Plaster of Paris. portland cement - Powdery substance produced by burning a mixture of clay and limestone at a high temperature. A primary ingredient in 'tufa. positive mold - A concave mold which prevents the escape of molding material during the molding process. 'puter - computer (Cajun). Rebar - Steel bars usually used in concrete to provide reinforcement. Can be used to make an armiture in 'tufa projects. 'rete - Concrete. ROTFLOL - Rolling on the floor, laughing out loud. Sand casting - Process of manipulating sand to create a mold, then filling the mold with 'tufa. silicon dioxide - Added to 'tufa mix increases density and water resistence via a chemical reaction. slurry - Paste made with portland cement and water. set - The initial hardening of 'tufa before it has fully cured. sn - Screen name. Spike - Gardenweb web master and ruler of the GW Universe. Tensile strength - Ability of 'tufa to resist stretching without breaking. 'tufa - Abbreviation for hypertufa. tufa - Naturally occurring soft or porus rock formed by water deposits. Tufa rock is artifically reproduced with hypertufa. Undercut - Portion of model which has sharp recesses which could prevent a mold to be separated from the model, or a casting to be separated from the mold. WIP - Work in progress.