Bending Timber

Question 1

What is the definition of a deforming process?

-Lucas M

Answer 1

Where material is reshaped without changing its state.

Question 2

Bag press laminating is a method to…

-Lucas M

Answer 2

Bend timber

Question 3

Why bend timber rather than cutting a curve from a solid block?
-Lucas M

Answer 3

Cutting a curve from solid timber creates a short grain section which is weak and liable to break along the grain.

Question 4

What does PVA stand for?

-Lucas M

Answer 4

Poly vinyl Acetate

Question 5

What is the setting time for Aerolite 306?

-Lucas M

Answer 5

25mins to 3 hours dependant on temperature

Question 6

What type of process is bending timber?

Ivan K

Answer 6

Deforming process

Question 7

Name this process for bending timber:
Many parallel cuts along the length of a piece of timber, but only some of the depth.
Ivan K

Answer 7

Kerfing

Question 8

What is the rule of thumb for the length of time to steam timber?
-Ivan k

Answer 8

One hour for each inch or 25mm of thickness.

Question 9

Cutting a curve from solid timber creates a short grain which does what to the timber?
- Humphrey Marsh

Answer 9

Makes the timber weak and liable to break along the short grain.

Question 10

Kerfing with timber is created by…

- Humphrey Marsh

Answer 10

A series of parallel saw cuts.

Question 11

When steam bending timber, the heat and moisture makes the timber…
- Humphrey Marsh

Answer 11

Soft and pliable.

Question 12

What force does a bag press uses what to push laminated wood against the former?
- Humphrey Marsh

Answer 12

Atmospheric pressure from outside the bag.

Question 13

Which deforming processes are commonly used with timber?

-Oscar Lawson

Answer 13

Bending or laminating of timber.

Question 14

How do you maximise strength when bending timber?

-Oscar Lawson

Answer 14

Try to ensure that the grain follows the profile or curve

Question 15

What conditions does a steam chest provide?

-Oscar Lawson

Answer 15

Saturated steam at 100 degrees Celsius

Question 16

What are the two main steps for laminating timber?

-Oscar Lawson

Answer 16

1. Glue strips or layers of wood together with a strong adhesive
2. Clamp them in a jig or over a former to keep them in the required form until the glue had cured.

Question 17

What is a former used for when bending timber?

-Oscar Lawson

Answer 17

A block around which lamina/ply of wood are put so that the strips adopt to the same shape.

Question 18

Any adhesive to be used with a bag press must be able to cure in the absence of ….
-Caspar Tyser

Answer 18

Air.

Question 19

What do curing times of adhesives mostly depend on?

-Caspar Tyser

Answer 19

Temperature.

Question 20

Does cross-linking (D3) PVA need air to cure?

-Caspar Tyser

Answer 20

No.

Question 21

Is Cascamite waterproof once cured?

-Caspar Tyser

Answer 21

Yes.

Question 22

Name the device used to heat and moisten timber before bending.
-OTC

Answer 22

A steam chest.

Question 23

What characteristic of grain is most important for timber which is to be bent?
-OTC

Answer 23

That it is straight grained.

Question 24

What is Kerfing?

-Yan K

Answer 24

A series of parallel saw cuts made on one side of the timber to allow that side to compress.

Question 25

What is the process of steam bending? | -Yan K

Answer 25

Lengths of wood are placed in a steam chest with saturated steam at 100 degrees Celsius. The supply of heat and moisture makes the timber soft and pliable.

Question 26

What does a bag press do? | -Yan K

Answer 26

Uses atmospheric pressure to push the laminated timber against the former.

Question 27

Is aerolite 306 suitable for wood? | - Ssnehnil G

Answer 27

Yes.

Question 28

Which needs to cure in air: Crosslinking PVA P3/D3 or regular PVA? - Ssnehnil G

Answer 28

PVA.

Question 29

Is bending/forming a reforming process? | - Ssnehnil G

Answer 29

No, it is a deforming process

Question 30

1 hour per 25mm thickness is a rule of thumb for which process? -Ed H

Answer 30

Steam bending

Question 31

PVA P3/D3 is? | -Ed H

Answer 31

Cross linking PVA which needs to cure without air.

Question 32

What is the main disadvantage of short grain? | -Ed H

Answer 32

It is weak and liable to break.

Question 33

Whilst bending timber, what would you use a flexible steel band to do? -Oscar Mabon

Answer 33

To pull strips over the former in laminating.

Question 34

Do the cuts have to be parallel during Kerfing timber? | -Oscar Mabon

Answer 34

Yes

Question 35

What is cascamite? | -Torsai K

Answer 35

A strong waterproof timber glue suitable for use outside.

Question 36

What makes timber soft and pliable? | -Nathan P

Answer 36

Heat and moisture.

Question 37

What visual feature gives away whether a timber component has been bent to shape instead of being cut to shape?

Answer 37

If the grain on a timber component follows the curves of the shape, it has most likely been bent to shape. However if end grain is visible around curves, then it has most likely been cut to shape.