Table of Contents
- 4About the measurements, Materials you will need and Informative notes
- 5Materials continued and cutting list for the form
- 6The plans - dimensions
- 7The form plans - schematic
- 8Step 1.1 Cutting and assembling the frame pieces of the seat form
- 9Step 1.2 Cutting the plywood, the plastic, and assembling the seat form
- 10Step 1.3 Cutting the form pieces for the legs
- 11Step 1.4 Assembling the forms for the legs
- 12Step 1.5 Aligning and bolting the leg forms to the seat form
- 13Steps 2.1 to 2.3 Cutting, shaping and tying the mesh
- 14Concrete mix information
- 15Steps 3.1 to 3.2 Dry and wet mix
- 16Steps 4.1 to 4.3 Applying the release agent, half filling the seat form and placing the reinforcing
- 17Steps 4.4 to 4.5 Topping up the seat form and attach the leg forms to the seat form
- 18Step 4.6 Topping up the leg forms
- 19Step 4.7 Releasing the leg forms
- 20Step 4.8 Releasing the seat form
- 21Appendage: Easier options
About the measurements, Materials you will need and Informative notes
This project is in four parts
Part 1. Making the form (mold)
Part 2. Preparing the reinforcing mesh
Part 3. Making the concrete
Part 4. Casting the concrete
The four parts will guide you step-by-step through all the stages of making the form (mold), preparing the reinforcing, making the release agent, applying the release agent, making the concrete, pouring the concrete, settling the concrete, removing the form, and cleaning-up.
There is also a page giving easier options, albeit for a less exciting seat.
Dimensions given throughout this project are in both imperial (inches) and metric (mm). The imperial measurements are given first, followed by the metric measurements in brackets ( ). For example: 2″ x 4″ (100mm x 50mm).
Materials you will need
• 11ft (3.3m) of 2″ x 4″ (100mm x 50mm) wood, allowing for a little bit of waste.
• 4ft (1200mm) of 2½” x 5½” (140mm x 62mm) wood.
• 13ft (3.9m) of ¾” x 5½” (140mm x 20mm) wood. * see Note 1
* Note 1: 2½” (62mm) thick wood is less common than ¾” (20mm) thick wood, and harder to cut the shape with a jig-saw (although it can be done). The ¾” (20mm) thick wood is more readily available and of course a lot easier to cut, but you will need three times as many pieces, as you will need to glue and screw three pieces together to make up for every one piece of the thicker wood. The thicker option is the best way to go if you can manage to acquire the wood (or close to it) and have the tools to cut it.
• 8ft (2400mm) of ½” (12mm) angle fillet, allowing for a little bit of waste. * see Note 2
* Note 2: Angle fillet is a triangular shaped strip of wood. Its purpose is to make a beveled-type edge around the top of the seat. You can use a different profiled piece of wood if you want something a bit more fanciful, or you can disregard it altogether for a plainer look.
• Half a standard sheet of ⅝” (15mm) thick plywood. A standard sheet is 4ft x 8ft (1200mm x 2400mm) so you will need half of that, allowing for a little bit of waste.
• I piece of ⅛” (3mm) thick plastic sheet, 40″ x 22″ (1000mm x 550mm). * see Note 3
* Note 3: The plastic sheet is to make a smooth finish on the top of the seat. The end product of a concrete cast will be as smooth as the form. The plastic sheet can be any thickness, or you can disregard it altogether, in which case the finished product will be as smooth as the plywood form. That can still be a reasonable finish.