Neil Miller said:
In another life I used to order in kiln dried wood for building houses - it is rubbish! The moisture is driven off the green wood so quickly that it then absorbs moisture from the air and develops buckles, cupping and splits.
I believe you. However, I know from experience that there is a difference in kiln-dried construction wood, and kiln-dried exotic wood for turnery and ornamental work. Which is understandable since destroying exotic wood by drying incorrectly would generate a horrific loss, driving any entity doing this out of business before you can say "kiln-dried".
I think that the advice given above is correct - about a season - 1 year - to get the moisture content down to around 25 - 30%. That's not the end of the story though - at those levels it responds to ambient humidity levels quite readily, so the next stage is to move it into the environment where it will be used. The whole process can take 2 - 3 years for timber that is in excess of 4" thick. If it is then moved out of that environment into one of lesser/greater humidity, you still run the risk of defects.
Which is why turners frequently turn wet/green wood to semi-final dimensions. The turned object will dry much faster, and will stabilize to final ambient temperatures. At that point, one can turn to final dimensions.
Turning it to roughly the finished dimensions, as stated above, will hasten the process, but leave you less width of error to play with. The thinner the wood, the quicker it will season. Good workshop practice involves wax-coating the cut ends to prevent splits.
True, and true. And true. I've never used up so much candles as in the last couple of years.
Once the timber has reached equilibrium with the environment you should be safe, but remember the tale of granny's old cupboard that survived in unheated houses since before granny was born - put into a modern house near a radiator it splits!
Will that affect small things like a shaving brush handle - I don't know. If at equilibrium point and then sealed with wax, oil or varnish probably not, but can water pentrate from the bristle end? If the brush is varnished - or whatever - is this done before the knot is glued in place?
A brush handle is small enough so that no major internal stresses (usually) develop. I'd be surprised if a handle turned from not completely seasoned wood would still split due to ongoing seasoning. However the point raised about the water a brush is exposed to in use is a very valid one. I make sure the outside is well sealed with a marine spar varnish (not the most beautiful finish for a nice hardwood, but necessary in this case). The bowl that holds the knot is completely soaked in epoxy. Now I know that many brush makers are adamant that no glue line should be visible between the handle (edge of the bowl) and the base of the knot. I concur that this is visually preferable, and poses no mechanical problem with resin, metal, or even horn handles. However with a wood handle, you really want to seal that gap between handle and knot, so I state that if you have a brush with a wood handle and want it to be durable, you'll have to accept a glue line, otherwise you can't be certain that that top edge of the wood will not in time absorb moisture and split. Or develop all kinds of interesting moulds...
This is one reason why I am going more to handles with a ring of faux ivory (a white resin with a ceramic (?) filler) at the brush end of the handle. This ring is impervious to moisture so that I can omit the glue barrier line between handle and knot, and still know that the wood below the resin ring is fully sealed on all sides.
Henk
