Guide to Making a Fish Mouth
The Fish Mouth is named after the way one bamboo piece “bites” into its counterpart. This traditional joinery technique makes use of the bamboo’s intrinsic properties by evenly distributing loads across the full section of the bamboo culm.
The art of making this joint can be broken down into the following steps:
1. Gather The Right Materials:
- Four pieces of treated dry bamboo, three have a larger diameter than the last one. For instance, with a Petung piece of 10 cm diameter, try to have a smaller piece of around 6 cm.
- An electric drill, with bits of 3 to 4 mm diameter
- A mutik (traditional bamboo carving knife), chosen according to your dominant hand (a)
- A curved chisel (b)
- A hammer (c)
- A few wooden dowels (at least 10)
- A pencil (d)
- A ruler/tape measurer (e)
- A hand saw (f)
- Protective wear
2. Prepare The Fish Mouth:
- i. To add strength to the joint, the top of the mouth on the column should be cut close to a node (use the diameter as reference).
Then, divide into four equal parts.
Between the node and the end of the column, draw a line around the surface. The distance from the end of the column and the line should be the same as the radius of the beam.
- ii. With your pencil, draw an approximate shape for your fish mouth.
Hold the column and saw along the diagonals
- iii. Then, carve out the mouth’s shape in upwards motions (working in the same direction as the bamboo fibers)
3. Make The Hole Joint:
- i. Take the third, smaller piece of bamboo. It will act as the tie between the column and beam.
- ii. Draw out its diameter on the beam, where the fish mouth will sit. Taking the chisel and the mutik, carve out the “hole”.
Slot the piece in, it should fit in tight and all the way through to the opposite culm wall.
Then, drill and dowel.
- iii. Slip the column over the smaller bamboo piece to secure the fish mouth to the beam. Drill and dowel through the column and the small bamboo at opposite angles.
In this form, the joint is commonly used for furniture design and smaller structures.
After finishing her Masters of Architecture at the University of Hong Kong where she wrote her thesis about bamboo construction for the rural communities of Bali, she now forms part of the Bamboo U Team as a Management Consulting Professional.
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