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When to cut blanks for turning?
Posted: Sat Mar 05, 2016 11:37 am
by moggymatt
For you turners out there:
In the last year I've been able to get a couple of loads of Locust, 1/2 a pickup of Walnut and 1/4 pickup of Hawthorn. All cut down to manageable sizes or as long/big as possible and the ends sealed up. How long do you wait to start blanking them out? Do I wait till just before making something or is it ok to break the bigger pieces down, reseal and put them up on a shelf till I want to use them?
Re: When to cut blanks for turning?
Posted: Sat Mar 05, 2016 11:53 am
by ChrisNeilan
Break them down as soon as possible and be sure to take out the pith. Just don't cut down the middle of the log, take out material on BOTH sides of the pith. Anchorseal the ends and a bit of the sides immediately! The resultant board can be used for pen blanks. Locust should be turned when still green. It becomes concrete when dry!. My favorite wood to turn. Many turners like to "twice turn", that is if turning a bowl green, turn it thick, let it dry and warp, then turn it again to final thickness. Turning is addictive!
Re: When to cut blanks for turning?
Posted: Sat Mar 05, 2016 12:37 pm
by benush26
Blanking out? As in roughing to bowl form or splitting the rounds lengthwise?
If you are planning to take them to rough bowl shape, then seal them ....
While wet it is MUCH easier to get a bowl in to rough shape, seal it and put it away for many months to a year plus, they can distort quite a bit in that time so getting them back into a reasonable form for turning still takes a lot of effort. I don't do this anymore but when I did, I wold have to leave the sides at least an inch thick to get a finished thickness of 1/4"
The other side of the coin. When allowed to dry before turning, the bowls retain the shape more closely to what you turn but hard woods are a real pain to turn when dry. You will sharpen HSS tools or replace carbide tips at a faster rate than when working with wetter woods.
When I have the option, I prefer splitting the rounds (actually cleaving with a wedge and sledge hammer rather than cutting down the middle), sealing the ends and flat surface, letting them thoroughly dry, then bandsaw to rough shape. I have a moisture meter but I don't consider it that useful (but then maybe I don't use it correctly!). I prefer the weight loss method. I place a piece of duct tape on one surface. Weigh the piece then write down the weight and date. At about 6 months I reweigh the pieces to see the weight drop, then 3 or 4 months, then every month. When the weigh stops dropping (or drops less than 2 percent in a month) I figure the wood has dried out and acclimated.
As for Locust, I have never turned it but did make a small keepsake box for a friend. It was kiln dried and I had a heck of a time cutting thinner pieces on the bandsaw so not certain I would want to turn it. But then again maybe I'm just too lazy!
The only Hawthorn I turned was for mallet heads (ash handles) so not certain how it will take a finish.
Hope that helps.
Be well,
Ben
Re: When to cut blanks for turning?
Posted: Sat Mar 05, 2016 12:39 pm
by masonsailor2
I will generally hedge my bets and do both if there is enough material to do so. Some blanks will lend themselves to green turning and some will not. Some blanks no matter how well you seal them after turning will check or warp beyond reclaiming them. In those cases the hope is the unturned blank will hopefully dry slow enough to be usable. A given percent will just end up firewood. As far as when to do the final turning I use a scale. After sealing put the blanks inside a paper bag. In the beginning you may have to change the bag fairly frequently. You don't want the blank sitting in a wet bag for too long. Then just weigh the blank bag and all and write the weight and date on the bag. When you have weighed it a few times and it stops losing weight it's ready for turning. You can weigh them as much as you like. I do it every month or so for the unturned blanks. They take about a year depending on how well you sealed it and the ambient humidity. A green turned bowl can reach equilibrium in just a couple of months. Also be aware that by sealing the blank, either way you will lose about 1/8" or more of material due to discoloration by the sealer. Hope this helps.
Paul