Newsletter 13th March 2013

The Village Turners. WED. 13th MARCH 2013

lnformation for U3A Members by Stan Knowles.

 

Over the next weeks ahead l will try and pass on hints on woodturning and finishing your work, also info on timbers, their properties and how they grow.

As many of you are now very good at the lathes but still at a loss which tool or what shape, how big or what wood or finish to use.

The wood to turn can be wet or dry. Wet wood straight off the tree such as a log means turning into end grain, if you are turning a bowl or vase, some woods can be very hard to hollow out but being wet it cuts easier. The tendency as it dries out it will split and change shape, the thinner the wall thickness the more it shrinks. To avoid this happening as much as possible keep the work damp by spraying water on it, packing the inside with damp chippings and cover with cling film if you leave it overnight. ln other words, slow down the drying time.

Dry wood, either in log form or a blank. A blank that you can buy at a wood yard is never really dry, at best it will be at 15% moisture

content; it needs to be 8% moisture content. Get a moisture meter; they cost about £20 upwards. A blank is usually marked part seasoned, meaning it is not fully dried and will shrink. Air dried is the best followed by Killen dried, the latter method is not suited to all wood.

Air drying takes one year for every inch in thickness of wood, so a blank taken from a 3 inch board has taken 3 years to dry and will still shrink if used straight away. So when you go to the wood yard, try and find a blank he has had in stock a while, or take your meter with you and see what the moisture content is. I try and keep a stock of blanks for up to six months before I use them. You can part turn a bowl which is too wet by rough turning to the near shape you are looking for, but leave the walls about one inch thick, put it in a dry place for a few weeks, then put it back on the lathe and finish turning.

Well that is all for this week, I hope I did not bore you too much.

Stan.

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