DIY Potter's Wheel or Turntable For Ferro-cement Projects

I borrowed this idea from pottery where a potter's wheel is used to shape round ceramic ware. Modern potter's wheel uses a motor or crankshaft and flywheel to turn the platform. Traditional pottery wheel uses a pivot system usually in the shape of an inverted cone and attached to the platform. It's hand-powered. My potter's wheel uses glass marbles as the pivot and ferro-cement for the platform and base.

I created this potter's wheel or turntable especially for my ferro-cement projects. It helps me turn the project assembly around as I work on it rather than walk over the other side.

Hand-powered Potter's wheel or turntable made of ferro-cement

A ferro-cement project assembly on top of the potter's wheel

Construction of The Potter's Wheel

This is a cross-section diagram of the potter's wheel which is constructed from cut-outs of a large plastic container, some glass marbles and ferro-cement.

Cross-section of turntable consisting of a base unit and top unit with glass marbles in between

My potter's wheel consists of a top unit which acts as a platform where I place my project assembly. The lower section of this top unit acts like a pivot and rides freely over glass marbles placed in a hole in the bottom unit.

The glass marbles act as ball-bearings to enable the top unit (pivot and platform) turn around easily when you move the platform with your hand.

The bottom unit is the container for the marbles.

Materials Needed

A large cylindrical plastic container (the size depends on how big you want to make the potter's wheel). Some glass marbles. Portland cement, sand and water for making the mortar. Iron rods and wire mesh.

Large plastic container (6 liters) used to hold ice-cream

Cut out the two pieces (top and bottom) with a pair of sharp scissors. See diagram below:

Cut-outs from the plastic container

Description

The pivot or base of the top unit sits on the marbles and the walls of the pivot kept in place by the walls of the bottom unit. Only the top of the marbles and the bottom of  the top unit are in full contact. There should be a small gap in between the concrete shoulders of the top and base units so that they do not touch each other.

Notice the small gap between the top and bottom units

The bottom unit has a circular hole with plastic part as the side walls. This hole is filled completely with a layer of glass marbles of the same size. The amount of marbles used depends on the size of the hole. If the hole is packed too loosely with only a few marbles, the top unit or wheel resting on the marbles would wobbled because of uneven distribution of weight. On the other hand, if too many marbles are packed in tightly, they would restrict free movement and the wheel becomes difficult to turn around with your hand. You can add some lubricant such as grease or motor oil for better motion.

Construction of The Bottom Unit

Start off by making the bottom unit. The diameter of the plastic mold should be 2 or 3 cm larger than your plastic container. Reinforced the base with some iron rods and wire mesh.

Cut-out plastic mold for the base

Pour enough mortar containing 1 part cement and 3 parts sand (the basic ferro-cement mixture) to cover the wired grid.

Basic frame-work of iron rods, wire mesh and mortar

Place plastic part in center and filled the sides with mortar

Then, place the cylindrical shaped plastic cut-out directly over the center of the mold. The inside section of plastic now becomes the mold for the hole where the marbles are placed. The outside section of this mold is filled with mortar and becomes the walls of the bottom or base unit.

Fill the empty space outside the circular plastic with mortar until it reaches the brim or top edge of the plastic. The height of this wall is critical as the hole you are creating should be deep enough to hold a layer of marbles plus about two centimeters of the pivot when the top unit is placed over the bottom unit. 

The bottom unit of the potter's wheel is now completed and left to harden.

This is how the bottom unit looks like when completed. It's a container for the marbles.

Construction of The Top Unit - Pivot and Platform

The making of the top unit of the potter's wheel follows almost the same steps above except that the plastic part came from the bottom section of the original plastic container and you make a pivot instead of a hole.

Start off by making the platform. The diameter of the plastic mold should be 2 or 3 cm larger than your plastic container. Reinforced the bottom with some iron rods and wire mesh.

Pour enough mortar containing 1 part cement and 3 parts sand (the basic ferro-cement mixture) to cover the wired grid in the mold. Now, take the cut-out plastic which is the cut-off bottom portion of the plastic container and filled it tightly with mortar. You would want this unit to be solid hard when completed as this is the pivot which rides on top of the marbles.

Construction of the top unit

The next step is a bit tricky. You have to invert the plastic part containing the wet mortar and place it directly over the center of the mortar in the base mold. I did it by covering the mortar in the plastic with a piece of hard cardboard. Then, I inverted the plastic part without any mortar falling off and placed the covered part over the center of the base mold.

Once it's in place, I removed the hard cardboard and the plastic part is now firmly embedded in the center of the mortar in the base mold. Next, I checked that the protruding plastic part has the height and alignment I needed. You may have to add or remove some mortar around the plastic part for this fine adjustment.

Completed top unit - the pivot and the platform

It would take a couple of days for the concrete to set.

Completely filled the bottom unit with marbles to ensure even distribution of weight
of the pivot and platform (the top unit)

Placed the potter's wheel onto a level platform or table

There should be a gap between the top and bottom units

You can place a zinc sheet or plywood on top of wheel for a bigger work platform

 

A ferro-cement project weighing about 15-20kg on top of the potter's wheel

DIY Ferro-cement Owl Garden Stool

Ferro-cement Owl Garden Stool

An owl garden stool created with ferro cement - my first such project using this incredibly simple method. So, what is ferro-cement?

Ferro-cement is a mixture of common Portland cement and sand applied over an armature or grid of wire mesh and small-diameter steel or iron construction rods.

Ferro-cement was called "ferciment" by its French inventor Joseph-Louis Lambot who constructed a small boat in 1848 using cement mortar (masonry) and iron reinforcement of iron rods and chicken wire.

In 1855, "ciment armé" was first used by another French man, Joseph Monier who created large urns, planters, cisterns and bridges. The bridge outer layer was sculpted to mimic rustic logs and timbers.

Ferro-cement is also known as ferro-concrete or reinforced concrete. It has a wide range of applications including sculpture and prefabricated building components.  It has relatively good strength and resistance to impact and can be used to form relatively thin, curved sheets to make hulls for boats, shell roofs, water tanks, roads, garden stools and ornaments etc.

The Making Of An Owl Garden Stool

You start off by putting your idea on paper and the Internet is a great resource for more ideas or information you might need as you embark on this exciting experience of ferro-cement construction.

Owl Garden Stool Drawing

  The Ingredients

Cement, sand and plaster lime mixture

The mortar consists of three basic ingredients - Portland cement, sand and water.

Usually, a ratio of 3:1  is used for most projects. This is make up of 3 parts of sand and 1 part of cement. A ratio of 5:1 is considered the maximum limit before the cement loses its properties.

A bag of Portland cement

Sufficient water is then added and mixed thoroughly with the cement and sand to form a consistency such that a line drawn with your index finger settles only slightly. Draw the line about an inch deep on the surface of fresh mortar and see how fast the line collapses. Too much water and the line collapses immediately. The trick is to add a little water at a time and mix constantly. If the mixture is too watery, add more cement until you get the consistency that you required.

Warning - cement cause irritation and damage to eyes

Putty lime

Sometimes an additive such as putty lime is added to make the mortar more "sticky" as well as to "strengthen" the mixture. This helps the wet mortar adheres easily to vertical surfaces of the mesh. 

A mold cut out from the top of a paint pail. This is use to make the base of the stool

 The Armature

The armature is the framework of iron rods and wire mesh constructed in the shape of object you are creating.

 You will need some tools and materials to help you construct the armature.

Some tools and materials needed for the project

You start off by constructing the armature. This is the foundation or skeletal structure of iron rods and wire mesh pressed and tied into the shape of your project. It can stand alone by itself or build upon a concrete base. For my project, I prefer the second option as it makes the armature construction easier.

I cut out the top section of a large plastic pail that was used to store emulsion paint. This will be the plastic mold to cast my armature base. I then constructed a simple framework of iron rods and wire mesh which I placed in the center of the plastic mold. Mortar is poured into the mold so that the wire mesh is completely enclosed in the mortar. The erect iron rods should be securely embedded in the mortar and become the skeletal structure on which the project armature is built upon.

Concrete stool base with iron rods frame

Some tools for plastering or sculpturing

A large paint pail is then placed in the center of the framework. I used the pail for two reasons - the side of the pail acts like a mold to support wet mortar being pressed through the other side of the wire mesh and it is also big and strong enough to support an adult sitting on it. The pail becomes an integral part of the framework. Secured the pail firmly to the iron rods with galvanized wire.

You do not have to use a pail for the backing. Any hard cardboard or crumpled old newspaper can be used instead as long as it can support wet mortar pressed through the wire mesh.

Another skeletal structure consisting of a framework of iron rods and wire mesh is then constructed at the top of the pail which would be the "seat" of the the garden stool.

A paint bucket is secured firmly in the center and a framework constructed at the top

Mortar is then poured into this upper framework which would eventually become the top section of the garden stool. It would take a day or two for the mortar to set or harden.

Use enough mortar to completely cover the wire mesh and fill the mold

When the "seat" is sufficiently hardened, the plastic mold of the framework is removed. The next step is to construct the armature or framework for the owl-shape garden stool all over this structure.

The armature consists of several layers of wire mesh of different sizes, pressed and formed into the required shape and then secured firmly with thin galvanized wire to the basic structure.

Several layers of wire mesh of different sizes form the armature of the owl garden stool

Mortar is then placed over the entire armature. It is very important that you press the mortar firmly into the mesh and to cover it completely. During hardening, any gaps or air pockets in the concrete would form cracks and weaken the whole structure.

The side of the bucket supports the mortar as it is pressed through the wire mesh

Armature almost completely plastered with mortar

Sculpting into the desired shape

Once the whole armature is plastered with mortar, the next step is to sculpt it into the desired shape. This is the most difficult part of the project as it requires some skill, lots of hard work and patience but it is also the most satisfying part as you begin to feel and see your creation taking shape.

The next step is the hardening or setting stage. During hardening, the assembly must be kept constantly moist by covering it with a damp cloth. This is to ensure that the concrete is able to set and harden slowly and to avoid developing cracks on the surface that can weaken the system.

Cover your completed projected with a damp cloth and keep it constantly moist

The hardening or setting stage usually takes about two to four weeks to complete depending on the size of the project.

The concrete has hardened and ready for painting

The Reward

My very own owl garden stool