Make Sure Your Form or Mold is Sturdy and You’ll Be Off To A Great Start!
You know, you can use almost anything when it comes to choosing sturdy forms for hypertufa or concrete projects.
The form — or mold — can be as simple as a cheapie styrofoam ice chest, to one made from pieces of wood screwed together for a trough project, as an example. A sturdy cardboard box can be used as a form for a hypertufa / concrete project. Almost any size plastic or metal bowl will work.
Some of the “ready-made” mold choices that are acceptable are:
- Sturdy cardboard boxes
- Styrofoam ice-chests
- Plastic containers/planters
- Plastic dish pans
- Plastic kitty litter pans
You can make your own square or rectangular forms for hypertufa or concrete objects with:
- Wood (screw the pieces together)
- Polystyrene foam used for house insulation
- Large sheets of styrofoam
A great idea for reusable forms for hypertufa or concrete: Butt the edges of (4) pre-cut rigid foam sections; hold the edges together with bamboo or metal cooking skewers, or large nails; then wrap duct tape around the outside for added stability. Put this 4-sided form on a piece of plywood for a removable base.
And I do want to mention this in case you’re brand new to making ‘tufa or concrete objects … most of the forms you will be using can have the hypertufa / concrete applied to the inside or outside. Keep in mind your item will be SMALLER than the mold if you apply your mixture to the inside; and it’ll be LARGER than the mold if you apply it to the outside.
And no matter what type of form you use, you will want to use some sort of a “release agent”. Please refer to my article: Release Agents: Their Use For Preparation of Concrete & Hypertufa Forms
Spherical & Terra Cotta Forms
Beach Balls, Exercise Balls, Soccer Balls or Clay Pots Work Fine, Too
Spherical hypertufa or concrete items can be achieved by using sturdy plastic beach balls or exercise balls. HINT: don’t use the really cheap inflatable kind as they can collapse during the curing process because the air leaks out one way or another.
Click here to learn about a very popular garden art project: Making “Hollow Garden Spheres”
Terra cotta pots can be utilized as forms for hypertufa / concrete projects, BUT will pose a larger degree of difficulty when trying to remove the “new” pot.
This is what you MUST DO: Soak the terra cotta item OVERNIGHT in water. Drain off excess water and generously coat with a combination of equal parts mineral oil and corn oil. This oil mixture is referred to as a “release agent”. It facilitates the “release” of the hypertufa / concrete from the form’s surface. Many folks swear by this oil blend and use it exclusively on all types of forms.
For more on “release agents”, please take a moment to read my article: Must-Do Preparation Techniques & Tips for Concrete & Hypertufa Molds
Wire Forms For Rocks & Flat Stones
There Is A Bit Of Versatility Of Shapes If You Use A Wire Form
For making small irregular forms for your projects (such as rocks), many crafters make the shape they want with chicken wire stuffed with wadded plastic grocery bags.
Or, you can actually hollow out the shape outdoors in the ground, pour in the hypertufa or concrete mixture and let it cure before removing. With this method, you will have one side that is quite flat. You can use this technique to make stepping stones, too.
For really BIG objects … well now we’re talking armatures, rebar, things like that. And that is a whole ‘nother article I need to write!