How to prepare logs for later turning?

[Larry L]

For most of my turning experience I've been fortunate to either purchase turning blanks, or to have access to a selection of suitable dry lumber leftover from other projects.

Over the Memorial Day weekend I had to cut down a 25 year old ornamental cherry tree that was otherwise healthy, but, unfortunagely, smack in the middle of where a new building is going up in about two weeks. As I did the cutting into logs I was thinking about eventual use of the wood in bowl turning projects. I now have a sizeable stack of logs, many 6-8" in diameter and 24" or so long, along with some rounds that are 2' in diameter and 20" long. There are also a number of branches 4" in diameter and several feet long. Among all of these are various crotch sections, etc.

All of these will need to dry before final turning, and I'm assuming that I will rough turn some wet.

My dilema, never having worked with fresh cut wood, is what to do next? Should the logs be end sealed as they are and left to dry, or should rough blanks be cut at this point, and those sealed? What's the best product for sealing green wood? At what moisture content is it possible, appropriate, to rough turn green wood?

Some wisdom from the experts here would be greatly appreciated.

Thanks.

Larry L

 

[Andy Coates]

green turning

Hello Larry,

You can turn them as soon as you wish to. In fact, because you've cut them into quite short lengths, the sooner the better. Leaving the log in much longer lengths allows you the scope to cut off the end sections that will inevitably check and split late.And Cherry is renound for it here in the UK.

You will need to rough turn the bowls to a greater wall thickness than the required finished thickness, set aside to dry, at which point you can seal the end and side grain if you wish with a proprietry end sealer, white glue (PVA here in the UK), old paint, wax, or anything that will retard the drying process.
Time frames seem to differ from turner to turner, but anything from three months to a year should pass before you finish turn them. You will lose the odd bowl to cracking but should find you win most of them.

If you wish to turn a few natural edge log bowls you can turn them fromstart to finish in one shot because the wall thickness (about 3-5mm) will remove most of the associated stresses and when they season, which they do in days, will only distort them a little, and this is acceptable in such a bowl.

If you need to leave some of the logs for any period then I would end seal them as soon as possible and store them out of sunlight and rain, but somewhere where the air can at least pass around them. This, of course, depends on your local climate. In the UK we have very few extremes of weather across the country, and on the whole little difference from one end to the other. I'm aware that the samecan not be said across the US and your conditions might indicate a different regime than for somebody living say in the desert areas.

I have in the past cut logs into more conventional bowl, plate, platter, square blanks, sealed them and put them aside to dry. I have found this process less reliable than rough turning, but still worthwhile when compared to leaving logs alone until time permits their turning.

Whatever you do, good luck and happy wet turning! Have you got a waterproof smock to turn in?

A good book on the use of wet wood is Turning Green Wood by Michael O'Donnell. There's a review here:

http://www.woodworking.org/WC/Garchive01/2_18byck.html

Andy

 

[KenN]

Larry,

You will get most of the ways to skin this cat , I'm sure. I try to fell trees in the winter (dormancy - sap and moisture down). I know that's not an option for you now, and those with more experience than I will have suggestions and perhaps amend mine. If the diameter is large enough for coring bowls (16" +), I cut about 8" longer than the diameter, remove the pith (center) section leaving two segments with the bark intact and seal the end grain and about 4" up the sides. I use Anchor Seal, but there must a lot of sealers out there. The extra length allows the wood to check in storage without getting too far into the first bowl, if at all. I've got some three-year old black oak and two-year black walnut I'm still working on. The walnut has checked worse that the oak and I suspect should be roughed out sooner. The oak is just now beginning to check into the outside bowl. It does need to be stored under cover (shed) and stacked with air circulation - tough not to do with tree sections. It will cure if you leave it as long as I have and will be tougher to turn than green (especially oak) allowing single turning with some distortion after finishing.

Best of luck!