Hypertufa Sculptures

Construction How-Tos For Carving & Scuplting in ‘Tufa

This article offers guidelines and a recipe for creating long-lasting hypertufa sculptures

In most cases, when one talks of hypertufa sculptures they mean tall upright objects. But that being said, you can use these guidelines for smaller objects, such as a small “garden face” you sculpt into a ‘tufa rock’s surface.

As with all hypertufa projects, I will repeat myself once again and say “practice makes perfect” when it comes to your desired outcome. Whether it’s the consistency of your recipe’s ingredients, or the final appearance of your sculpting, carving and/or texturing of the object, please understand that sometimes your first project may be a big, yet necessary “learning curve”.

This isn’t rocket science, but being familiar with the “basics” comes with practice.

Sculpting Recipe

Here is a recipe that will give you a durable, carvable and long lasting hypertufa sculpture. Your aim is to apply this first recipe in thin layers over your armature, building it up to the desired thickness. Then, you will use the 2nd recipe to add one or more layers thick enough to allow you to sculpt to your desired depth.

Recipe for application over the armature and to build up thickness desired:

1 part Portland cement
1½ parts peat moss
1½ parts coarse sand
Handful of poly fibers
Handful of silica fume

Recipe for the Final Layer(s)

1 part Portland cement
1 part peat moss
1 part coarse sand
Elmer’s Carpenter’s Exterior Wood Glue (or other bonding agent)

Sculpting and Carving

Hyperutfa Sculpture

As mentioned above, once you’ve gotten the hypertufa sculpture’s walls almost as thick as desired, you will apply the final coats of the 2nd recipe. You will apply these last coats thick enough to allow the desired depth of your sculpting (or carving). Once the final layers have set up a bit, start your sculpting. Don’t let it set up too long or it’ll be too hard to properly sculpt.

You may wish to finish off the semi-cured surface with a stiff wire brush to get the surface smoothed out (if that is part of the final look you are trying to achieve.)

These are good basic directions for a successful hypertufa sculpture project. If you are brand new to working with hypertufa, then I whole-heartedly suggest you refer to my other articles to familiarize yourself with important facts before you attempt this project.

About Bonding Agents and Glue

What Is A Bonding Agent? How Much Should Be Used In Your Recipe?

A bonding agent is an additive used in a hypertufa recipe to cause a “new” layer to adhere to an “old” layer. In other words, you are able to apply layer upon layer of ‘tufa and everything will stick together. Now, this is a good thing! 🙂

Bonding agents are located in the cement products isle at Home Depot or Lowes, for example. A bonding agent is similar to Elmer’s Wood Glue, thusly many crafters use Elmer’s Wood Glue with great success (and save a little money, too).

The amount to use is not set in cement (not to make a pun) but in general for every 10 cups of dry mix ADD approximately ¼-cup of bonding agent. I suggest you add it into the water that you’ll use to moisten your dry mix.

NOTE: I’ll mention that rumor has it that the maestros “Little and Lewis” use Elmer’s Carpenter’s Wood Glue as their bonding agent. I’m just passin’ along some interesting info here, gang!

Armature: A Strong Inner Frame

The Sculpture Must have a Very Sturdy Inner Frame Construction

You’ve got to use something very sturdy on which to build hypertufa sculptures. But, almost anything can be utilized: PVC pipes, wooden structures, metal rods or rebar. Styrofoam can be used successfully, also. Build your armature by nailing, gluing or welding it into the ‘shape’ you want.

You will then use hardware mesh (also referred to as hardware cloth) to cover the armature. This will serve as your form on which to apply the hypertufa layers. Wrap it and wire it to your form if needed. Make sure the hardware mesh is secured as tightly as possible to the armature.

Due to the complexities involved with building an armature, there is no way in this particular article that I can address all the how-tos. Your ingenuity and creativity will certainly come into play in this particular step of your sculpture project. Let common sense dictate the particular requirements that your inner frame will need.

May there be many hypertufa sculptures gracing your garden in years to come! 🙂

Comments

  1. Julie Patton says:

    Hi we are making a queens head sculpture for the birthday celebrations in our village. It has been built so far using clay dung up from the ground, this has been applied to a brick and wire base. Obviously this is beginning to crack. After some research I can across your web site and am now rather excited about using hyper tufa. I am trying to work out the best way to do this, weather to take the clay off and start again, or to use wire and the hyper tufa mix over the top. My main concern is that this mix is porous and will effect the clay structure underneath thus causing the hyper tufa to crack.
    I was just wondering if you had any thoughts/ ideas on this.

    Julie

  2. Claudia Brownlie says:

    Hi Julie: Thank you for your question – hope I can be of some help to you here.

    First, yes – do remove the clay that was put on the form, because as you’ve already surmised it is not a solid base on which to apply any type of additional material, whether hypertufa or not.

    Next, as I preach all over my blog and in my Hypertufa How-To Manual eBook I strongly suggest you first do a small project to get used to working with hypertufa; from the proper ratios of ingredients to how to apply it, how well it is curing (which will let you know if your recipe contained the right amount of ingredients, especially the water ratio), etc.

    The Portland cement can be a tricky ingredient to work with – even professionals who pour concrete sidewalks, driveways, and such can have a batch that just goes “wrong” on them, and the same holds true for crafters who work with hypertufa. As example, the ratio of water – either just a little too much or not enough – can spell complete disaster for the entire project. The ratio of water used is the #1 reason for hypertufa project failures.

    So, you have 2 options here: choose a recipe, mix it up and then apply over your form if you “just can’t wait” to do the queen’s head, or err on the side of caution and do a small test project (such as a trough or small planter) and see what happens. Write down your recipe ratios and all the steps you took, as if you have success, then you know what you did correctly! But if your ‘tufa starts to crack or slump-off whatever form you’re using in the early period of the curing process … then you’ll have a record of what you might have done wrong.

    Good luck! 🙂

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