What are some general instructions for mixing hypertufa?
These instructions were kindly submitted by members. Thanks to all who contributed!
INSTRUCTIONS FOR HOW TO MAKE HYPERTUFA
To begin, you will need the following:
1. A hypertufa recipe (There are many recipes! See the FAQ for some of the most popular ones.)
2. Fine Particle dust mask
3. Dishwashing gloves
4. Disposable latex or plastic gloves
5. A measuring (parts) container The "parts" container you use is the container you fill with the different ingredients. It can be a cup or a bucket, or anything in between. It is a volume container.
6. A plastic mixing container (a flat plastic pan or tub is preferable to a tall, deep one)
7. A bucket of clear water and a small container to dip the water
8. A prepared mold, form or idea for free form
9. Mold release product, if using a mold
Plastic wrap, or old dry cleaner bag or garbage bag to cover your work
The time to come back to your project and mist with water when needed
A shady place to keep it out of direct heat or sun
A barbeque brush, wire brush or other bristle to rough up the surface
Carving tools - chisels, files, nails, etc. to carve into the project if you wish
Patience for, at the VERY least, several hours to a couple of days, prior to removing your project from the form or mold and finishing the surface
Optional: a small tub or wading pool to set your project in to cure after it has dried for a couple days (drying is different from curing). This step allows the hypertufa to gain strength during the curing process.
To any of the recipes, you will need to add water - a little bit at a time until the mix is just wet enough to hold a fist size without much water squeezing out or the mix slumping through your fingers. Let the mix sit a short time so that the additives (peat, perlite, vermiculite, sand, etc.) can soak up a bit of the liquid. Add a little more water, if needed.
If you want to add colorant to any of the mixes, remember that dry colorant is added when all the dry ingredients are mixed. If adding liquid color, add it to your first addition of water.
If you want the mix to be a bit stronger you can add either a small portion of liquid fortifier with the first addition of water or a pinch or two of fiber mesh to the first addition of water, being sure to swirl it around to distribute the fibers (the amount is subject to the size of the project). With fibers, you may end up with a hairy/stubby surface on your finished project. If you do not want a chia pet, burn the fibers off with a small torch.
Be sure to use a release agent in your mold for hypertufa. Another way is to cover your mold with a thin layer of plastic before putting the hypertufa in. Plastic forms can be sparingly coated with concrete mold release, cooking spray, Vaseline, WD40, cooking oil, motor oil, etc.
You can purchase large bags of perlite and vermiculite at a garden warehouse, co-op, concrete spply company, and farming supply stores. The...