Stage 3 of the design process

Introduction to materials, treatment and joints.

This PowerPoint Presentation is developed and created by :

Review of Homework

• Can we see your group’s designs?• Who is the chairperson?• How does your design meet the needs of each

stakeholder?

• The final presentation of your design will be next session. Think about the joints, treatment techniques and materials you will use...

Materials/ Techniques

• Today we are going to investigate different materials and techniques that may be useful in the construction of your design:

– Treatment– Joints– and Bending

Traditional Methods

(Reference Practical Actions’ Technical Brief on Bamboo reservation)The advantages of these methods are that they are very cheap and can

be done without chemicals or special equipment.

• Clump-curing The culms are cut, but left in place in a vertical position. The evaporation in the leaves reduces the starch content and consequently beetle attack. However, attack by rot and termites is not diminished.

• Smoking The bamboo is stored above the fireplace. The smoke will blacken the culm and might cause cracking too. The effect on durability is doubtful.

Traditional Methods Continued

• Soaking The culms are placed (immediately after the harvest) in water or mud with stones on top of them to keep them down. They are left for several weeks and then dried over a full week (in the shade, not in the sun!).

• Seasoning Bamboo has to be dry. This is achieved by drying in the open, under cover, with as much air movement as possible. It can take one or two months. A general remark to end with: if the local population has a tradition of working with bamboo they will know best the differences in natural durability between the several local bamboos as well as the effectiveness of traditional treatments for various end uses.

For our Bamboo chair...

• For our chair we primarily will use the Smoking method. But feel free to experiment with the other methods.

• Remember to put out the fire after use!

Untreated and Treated Bamboo

Joints

• Joints are very important to the design of your chair. They are crucial to ensure stability.

• There are many different types of joints. • See the PDF

‘CIBAM_BambooConstructionManual’• Double click hear

• It is recommended that every group receives a printed copy of this document.

• Experiment with joints and try to build some of the joints shown in CIBAM_BambooConstructionManual

• Use bolts, fittings and rope to secure the joint. • Which do you prefer?

• On the next two slides, can you identify L, K and Y joints?

Experiment with joints

Bending

• You can also experiment with curving or bending the bamboo.

For bending by heating:You need:• LPG Burner• Rope/Wire or String• Matches/ lighter

If you see creases in the bamboo, it means it has failed...

• Bending takes patience – bend, let it cool then bend again.

• Experiment with small bits of bamboo...

• What happens after one day when you remove the string?

• Does the bent bamboo keep its shape?

Other techniques...

Homework

• Next session we would like you to present your designs as a group. We will then select the best group or groups to build their chair.

• However everyone will be involved in building the chair(s).