Hand caring a wet wood drinking cup

Thought you guys might enjoy this. There are some good litle videos on this website.

http://wn.com/Hand_carving_a_wet_wood_drinking_cup

Interesting to see his technique. Now, I have only worked with seasoned timber, and my first thought watching that is, how do you prevent the wood spiltting as it dries ? It looks to be quite thin in places, so I would expect it to dry out rapidly and crack. Or is it a question of using the right wood ?

I should confess that my PC at work has no speakers, so I can only watch and not listen, maybe my questions are answered if I could ...

He talks about choosing the right part of the wood (but sadly doesn't go into much detail) so that the drying process is even. That said, his style is quite organic so I wonder if he'd happily accept the odd distortion or 'shake' in a piece as simply part of its unique character.

Fun to watch though.

(Meant to add - that whole thing took him about 3 hours to rough out.)

Thanks for filling me in .. Yes, I like the character and the organic curves, but in a drinking cup although character is good, being watertight is rather fundamental !

Too true! Have you looked over on the Bodger's forum? Nice bunch of guys & very helpful. You ask them anything to do with the topic and they'll happily share their knowledge.

http://www.bodgers.org.uk/bb/phpBB2/index.php

I've started to do a bit of looking at how wood cures, as I'm interested in getting more into greedwood working too. What I've read so far is that the drying defects can be managed by rate of drying, method, and of course wood choice. As wood dries, the first thing to go is the free water, in the pores, in the cells, until it reaches the Fiber Saturation Point (FSP). Once that 'excess' water is gone, the water bound in the cells and cell structure begins to dry. Once the water percentage goes below this FSP, that's when the 'real' drying begins, when the wood starts to become harder and changes its structure. Water moves more easily along the grain of the wood to an exposed cross cut, but the majority of the exposed surface area will be along the grain in a finished piece. Consequently, the areas about the exposed cross grain (end of workpiece) will typically try to dry most rapidly on that first edge, while the rest of the wood has to wait for its water to move across cell layers to dry out from the surfaces. This results in a disparaging rate of structure change from the end area of the wood to the more interior regions. This places stress on the piece, and subsequent drying defects. One of the methods used in commercial drying kilns which would be usable by the home woodworker could be to apply wax along the cross grain leading edge to deliberately slow down moisture loss at the extreme edges, and alow the rate to be more equal across the entire piece. Basically, seal the rim and the butt of the glass. The types of stresses also apply from the difference in drying rates of the surface to the interior as well. Maybe not so much in a thin wall cup, but probably depends with wood choice again. What the "big guys" do to prevent this differential stress (known as case hardening) is to control the humidity of the air during stages of drying. They will only vent off humid air for dryer gradually as the wood dries (by regulating the rate at which fresh air is exchanged) to match the rate at which moisture travels from interior areas of the wood to exterior. This may not be so feasable for the home woodworker, but older workers in the know may just have recipes for wiping damp cloth on the work piece XX many days in a row as it dries, or some other moisture management control. Not sure how much of this is actually usable information at hand, but just trying to pass on some of the things I've been reading lately. Good Luck!