Is it possible.....

[Stigmorgan]

Sorry if this seems like a daft question, Is it possible to predict how something will warp/twist/bend when made from green wood? I have some very wet wood (mostly small branches) and I'm toying with using them to make some icicle style christmas tree ornaments to go with the other ornaments I've been making for the school Xmas fair and I feel like they would look nice with a slight warp/curve/curl to them once turned, so is it possible to predict to any extent how they will move in relation to orientation of grain as in spindle, 45 degrees through the heart or endgrain turning.

 

[Tris]

It depends a lot in the species and whether it's trunk or branch wood. Branches have tension wood on the upper surface ( springs out when cut) and compression wood underneath (curls in when cut). That's the simplified version anyway. For twist, some tree species grow with a distinct spiral that will show if you split a length with an axe
Split a couple of lengths into quarters tonight and leave them somewhere warm, by tomorrow evening you'll have a fair idea if it's thin wood.

 

[Richard_C]

As above - and species vary a lot. I had some recently cut greengage, decided to part turn it then season, got the first one into a thick bowl shape, went indoors for lunch, came back and it was split beyond redemption Similar thing with maple was fine.

You could do a speeded up trial in 15 minutes with the help of your microwave - I have had success with small bowls although they do distort.

Turn one or two but don't finish. Pop them in the microwave loosly wrapped in kitchen roll, medium power for maybe a minute. It and the paper roll will feel very damp. Take it out and leave for a few minutes while the surface moisture dissipates. Repeat, maybe twice more. You sort of know when it's done. See what you have got, if its horribly split give up, if its nicely distiorted it's a win, if its the same shape as it was when it came off the lathe, be amazed.

 

[Paul Hannaby]

You can probably predict in which direction the wood will move due to the usual shrinkage of growth rings but as some wood has other stresses stored in it, it doesn't always do the same thing or move by the same amount. One other thing you can do is to either steam the wood and bend it how you want or clamp it to force a bend while it dries.