Tuesday 21 December 2010
Tony Davis looks at the technique of using
a microwave to dry out your timber, ready for turning
Microwaving wood is a great way of drying timber quickly with very little fuss. Many people have experimented with the concept to great success.
A microwave can bring the drying time of rough-turned pieces down to around one week, without the risk of the wood degrading. This method is a lot quicker than waiting for rough-turns to dry in a workshop. Opposite you will find a few simple pointers, and handy hints, to help set you on your way to using a microwave effectively in your workshop.
For the second part of this series, I will look at how you can successfully steam wood.
To start, you require the largest internal size microwave that you can obtain. This will enable you to hold a large variety and size of items. This is where the woodturner's best friend comes in: cling film. Rough turn the piece and wrap tightly in cling film, then place in the microwave and set on defrost
The time depends on the volume of wood placed in the microwave, and if you are using the turntable. For a 255mm (10in) bowl that is 25mm (1in) thick, I set the timer for six minutes. The bowl will come out quite hot and must be left for a while to cool, then, place back in the microwave to be reheated. This is done as many times as possible over a two-day period
After about 15 insertions, cut the centre of cling film on the inside and round the dovetail to allow the water to evaporate. Carry on microwaving for a couple more days, watching for internal cracks
Remove the cling film completely and microwave until bone dry - use a moisture meter, if possible - then remove, let the piece pick up the moisture and relax. It is now ready for re-turning and finishing