Bending+and+Shaping+Timber

Bending and shaping solid Timber
Bending timber in its seasoned stae is very difficult to do in large sections. smaller sections sizes like beading may bend slightly aorund a larg radious, but in general they are under stress because of seasoning shrinkage and so don't want to bend and will likely break if not treated correctly.

There are several methods employed. On this page you can find information on:
 * 1) Laminating timber - cold pressing and Radio Frequency heating to support laminating
 * 2) Steam bending
 * 3) Wet bending
 * 4) Saw kerfing

Advantages of bending solid timber: In the video below you can see how much effort goes into the actual bending process. Note the girl at the end of the stool holding the bench /jig down to counteract the leverage on the bending jig
 * less waste - saves timber
 * stronger shapes
 * cheaper core stock can be used
 * radical shapes can be created

Steam bending timber:
Steam bending requires the careful selection of timber, the right application of heat via steam over time. It also requires the careful accurate construction of jigs, cauls or templates to provide the shape required.

An example of steam bent timber used in a chair: media type="custom" key="8907472" width="130" height="130" See a video of how it works media type="youtube" key="OOIJXDZXB3g" height="390" width="480" to steam bend timber you will need to make a steam "oven". They can be easily "home made". the document below has details on making a steam box. Careful though its American so sizes will have to be converted to metric for Australian use. For sizing and time in the oven a rule of thumb seems to be allow 1 hour for every 25mm of thickness of material. Of course the radius of the curve will be important as well as the species too. [|http://www.timber.net.au] has provides specific details on suitable bending species, so select the material carefully. Check under the species link to find suitable timbers; [] Your trainers may ask you assess the sutability of some speies for bending or ask you to make recommendations on a suitable species.

Saw Kerfing
Saw kerfing invovles the removal of material using a sliding table saw or radial arm saw from the back (to be hidden) face of a piece of material. Sometimes timber is used, as in the curved "D" end of a stair riser or sometimes MDF. The trick is in know the radius or diameter of the curve you want to form, the circumference of the shape and the thickness of the material to be used. These dimensions are used to determine how many saw cuts (allowing 3mm /cut or kerf) are needed. Your trainer will teach you the calculations:

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