Here's a rookie question. I've turned a few bowls and lots of pens. But, I would like to try a few boxes. I have a nice selection of branches from Live Oak, Sweetgum and Cherry trees. The branches range from 4 to 8 inches and more in diameter. Can I turn those branches to make boxes? If so, don't I have to worry about pith? I guess I've thought that when cutting up large logs that the pith should be cut away. But when I look at some photos at webturning pages, it looks like they have small branches mounted on their lathes and aren't worrying about pith. Thanks for taking the time to help.
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Turning Branches
- Thread starter Al Stramiello
- Start date
Turning a branch
We just had a demo by Jimmy Clewes, in which he turned a very thin walled vase from a citrus branch. It was about 6-8 inches in diameter and very green. He said the big thing is not to have the pith in the exact center of the base but rather off center. When I started turning before I learned it wasn't a good idea, I had turned a few boxes from cedar with the pith in the center or slightly off center. It cracked very little for some unknown reason. I don't think I knew about superglue then but now I would watch it closely and superglue it at the first sign of a crack. I wonder if soaking in DNA would help stop it for cracking. I did recently turn a birch limb box. I had planned on rough turning green then soaking in DNA, but before I could finish roughing it , the bottom cracked. I soaked it in DNA and the cracks closed somewhat and I then superglued it . It looks pretty good but you can see the cracks. I might have been better off filling the cracks with coffee grounds or bark as discussed on this forum in various places.
Frank
We just had a demo by Jimmy Clewes, in which he turned a very thin walled vase from a citrus branch. It was about 6-8 inches in diameter and very green. He said the big thing is not to have the pith in the exact center of the base but rather off center. When I started turning before I learned it wasn't a good idea, I had turned a few boxes from cedar with the pith in the center or slightly off center. It cracked very little for some unknown reason. I don't think I knew about superglue then but now I would watch it closely and superglue it at the first sign of a crack. I wonder if soaking in DNA would help stop it for cracking. I did recently turn a birch limb box. I had planned on rough turning green then soaking in DNA, but before I could finish roughing it , the bottom cracked. I soaked it in DNA and the cracks closed somewhat and I then superglued it . It looks pretty good but you can see the cracks. I might have been better off filling the cracks with coffee grounds or bark as discussed on this forum in various places.
Frank
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Some woods are friendlier than others about leaving the pith. Note the elm I posted above, and the maple goblets in my album. What you can do to help yourself is remember that the killer split starts not at the center, but the outside of the log. Splits in the center, surrounded by contracting wood, tend to close. So allow the wood a place to contract by hollowing before drying, and allow it to dry more evenly by elevating the base on stickers so the bottom doesn't stay wet while the top dries, causing a split.
Generally speaking, if you can cut thin at once and get what you're after in design, you'll survive a greater percentage of pieces. Got on a goblet tear and did a bunch a year or so ago without losing a one, once I started using my head and the knowledge of what the wood was trying to do. Others will come in with reinforcement gluings and so forth, but I find simple care in drying to be the best way to flay the pith feline.
Generally speaking, if you can cut thin at once and get what you're after in design, you'll survive a greater percentage of pieces. Got on a goblet tear and did a bunch a year or so ago without losing a one, once I started using my head and the knowledge of what the wood was trying to do. Others will come in with reinforcement gluings and so forth, but I find simple care in drying to be the best way to flay the pith feline.
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john lucas
AAW Forum Expert
I teach turning branches to make hollow christmas ornaments but I don't recommend it for boxes. Leaving heart in is inviting a crack. I have them mount the wood so the pith is centered and then drill out the pith before hollowing.
There are ways to reduce this to a minimum but it's always a risk. The wood around the heart will always move. If you leave that area flat (like you might in a box) it will almost always crack. This is because the pith want's to draw up around the edges. If the edges are flat it can't draw up so it will crack. If you can leave this area cone shaped or in a curved section it will hopefully move and not crack. It usually puckers up around it but if the wood is thin enough it will be less likelly to crack.
Your best bet for boxes is to cut the wood well outside the pith on a larger log. Then rough shape it and dry it in the microwave. It will usually warp a fair amount and you may lose some but it's free wood. Don't waste time shaping it too carefully before you dry it. That way if it dies you haven't lost a lot of time.
There are ways to reduce this to a minimum but it's always a risk. The wood around the heart will always move. If you leave that area flat (like you might in a box) it will almost always crack. This is because the pith want's to draw up around the edges. If the edges are flat it can't draw up so it will crack. If you can leave this area cone shaped or in a curved section it will hopefully move and not crack. It usually puckers up around it but if the wood is thin enough it will be less likelly to crack.
Your best bet for boxes is to cut the wood well outside the pith on a larger log. Then rough shape it and dry it in the microwave. It will usually warp a fair amount and you may lose some but it's free wood. Don't waste time shaping it too carefully before you dry it. That way if it dies you haven't lost a lot of time.
MichaelMouse said:
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Nothing, unless you set up a new moisture differential to apply new stresses, change the dimension or shape of the piece, or apply them in other ways, like dropping a 16" dry cherry rough from about six feet and letting it land on end grain. :mad: Of course a box, with inside protected from what's outside by design is sort of a setup for differential stress.
I believe that continuing seasonal cycles eventually give enough set to the wood that it won't ever regain its saturated dimension.
I believe that continuing seasonal cycles eventually give enough set to the wood that it won't ever regain its saturated dimension.
Richard Baker
RIP
MM,
Do you turn any "un-dry" oak? What is best procedure, if any? Have roughed a couple of 14" pieces to 1-3/8" wall and sealed the outside, but may not see them dry enough to finish in my lifetime. Similar to your procedure, except between centers rather than with pin chuck.
Do you turn any "un-dry" oak? What is best procedure, if any? Have roughed a couple of 14" pieces to 1-3/8" wall and sealed the outside, but may not see them dry enough to finish in my lifetime. Similar to your procedure, except between centers rather than with pin chuck.
wet-wood boxes
I don't turn too many boxes boxes from wet-wood, but have been lucky with those that I have. If you take the precautions MM has detailed you should be lucky more often than not. It's all in the stresses you leave in the wood. Lid and bottom are always likely to dry at different rates and lead to distortion...if you're not careful.
I do turn an awful lot of hollows and vases from green wood, and seem to have a very good success rate...in fact, I can't remember the last failure due to stresses and cracks...although I can remember slicing through the side wall whilst hollowing out - it was only yesterday so it's still a fresh and painful memory!
If I have a technique, which I suppose I must have, it would be this:
pith off centre
even wall thickness - to include base
don't generate too much heat during abrading as this will speed up the drying process and aggravate checking
once complete, allow the piece to dry out slowly in an even temperature and non-extreme humidity environment
If you do see a crack starting after completion, give it a shot of CA, and, where required, sawdust/grounds etc., clean it up, re-finish the surface, and continue your vigil over it.
Here's a green turned vase in London Plane I completed last week. No sign whatsoever of any problems so far, and it's now in doors.
I don't turn too many boxes boxes from wet-wood, but have been lucky with those that I have. If you take the precautions MM has detailed you should be lucky more often than not. It's all in the stresses you leave in the wood. Lid and bottom are always likely to dry at different rates and lead to distortion...if you're not careful.
I do turn an awful lot of hollows and vases from green wood, and seem to have a very good success rate...in fact, I can't remember the last failure due to stresses and cracks...although I can remember slicing through the side wall whilst hollowing out - it was only yesterday so it's still a fresh and painful memory!
If I have a technique, which I suppose I must have, it would be this:
pith off centre
even wall thickness - to include base
don't generate too much heat during abrading as this will speed up the drying process and aggravate checking
once complete, allow the piece to dry out slowly in an even temperature and non-extreme humidity environment
If you do see a crack starting after completion, give it a shot of CA, and, where required, sawdust/grounds etc., clean it up, re-finish the surface, and continue your vigil over it.
Here's a green turned vase in London Plane I completed last week. No sign whatsoever of any problems so far, and it's now in doors.
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Texian said:
Oak and other ring-porous stuff can take forever to dry, can't it? I've taken pieces of firewood cut and split two years and when bandsawn, they're dark and wet in the center. Same-o black ash. Think it has to do with the larger pores drying rather than continuing conducting by capillary action. Fortunately our northern red is almost fungus-proof.
Mount and swing the beggar, truing down in dimension, throwing unbound stinking corrosive water all over your other tools, then stuff compressed air through it to get all the unbound water you can out of it. If it's got reasonable annual ring interval and curvature, you can certainly go to an inch or less on a 14" bowl. After that, dry down as if green. There are so many varieties of red oak out there it's tough to predict outcomes, but getting the unbound water out seems to be the problem, so try that method.
I have turned lots of green tree limbs. One thing I would add to the above threads is to put a finish, polyurethane, etc. on the turning as soon as it is finished. I have found that I can turn green wood, sand and put a finish on, and while it may warp, I have had very few crack.
On really wet woods, I rough turn, microwave a few times, then put back on the lathe, turn it like I want, sand and put a finish on.
On really wet woods, I rough turn, microwave a few times, then put back on the lathe, turn it like I want, sand and put a finish on.
Richard Baker
RIP
Wet Oak
Thanks, MM! I'll try the compressed air trick next time. Still have four chunks of it, plus another dead tree. Post oak, standing dead for more than a year and still wet inside. I spray the bed with Boeshield T9, cover that with plastic, and still some of the nasty stuff gets through. I think the T9 helps when cleaning it off and minimizes the residual stain.
Thanks, MM! I'll try the compressed air trick next time. Still have four chunks of it, plus another dead tree. Post oak, standing dead for more than a year and still wet inside. I spray the bed with Boeshield T9, cover that with plastic, and still some of the nasty stuff gets through. I think the T9 helps when cleaning it off and minimizes the residual stain.
Texian, I do turn wet oak.
I love to turn wet oak. I turn it to finished thickness (around 1/4", mostly; sometimes thinner) and let it do what it wants to do (which is move and crack and twist and bump up, and such). 😱
I live in dry, NW Texas, so while turning it, if I have to stop to eat or otherwise leave it for a while, I spray it with soap solution and put a plastic bag over it with rubber band... this pretty well helps to keep it from cracking. If I'm taking quite a while to turn the inside, I also spray the outside occasionally. 🙂 Also, by the time I've finished turning and sanding it, it is usually dry enough to put a danish oil or lemon oil finish on it. Then I buff it after it truly finishes drying (after a couple of weeks or so).
You can get some really interesting pieces this way. 😀
Texian said:
I love to turn wet oak. I turn it to finished thickness (around 1/4", mostly; sometimes thinner) and let it do what it wants to do (which is move and crack and twist and bump up, and such). 😱
I live in dry, NW Texas, so while turning it, if I have to stop to eat or otherwise leave it for a while, I spray it with soap solution and put a plastic bag over it with rubber band... this pretty well helps to keep it from cracking. If I'm taking quite a while to turn the inside, I also spray the outside occasionally. 🙂 Also, by the time I've finished turning and sanding it, it is usually dry enough to put a danish oil or lemon oil finish on it. Then I buff it after it truly finishes drying (after a couple of weeks or so).
You can get some really interesting pieces this way. 😀
Last edited:
john lucas
AAW Forum Expert
In log form the wood takes much longer than 1 year per inch to dry. I read the reason why somewhere in a technical piece of literature but have forgotten the reason. In bowl form they dry fairly quickly. I don't remember exactly because I rough turn stuff and just put it on the shelf but I'd say about 6 months here in Tennessee for a bowl 16" and 1" thick.
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Jimmy Clewes did a 4 day handson worskhop at our house.
The students all turned a vase like Frank Alvarez mentioned from Jimmy's demo.
the photos have one on the lathe and 3 with the turning completed.
these are all from eucalyptus limbs about 6" in diameter.
a nice way to get a finished piece from green wood.
- Al
The students all turned a vase like Frank Alvarez mentioned from Jimmy's demo.
the photos have one on the lathe and 3 with the turning completed.
these are all from eucalyptus limbs about 6" in diameter.
a nice way to get a finished piece from green wood.
- Al
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Richard Baker
RIP
Wet Oak
Al N.,
Thanks for your response! Was indeed considering turning the next chunk to "finished" thickness and see what happens. I do keep the piece wet while roughing, and use the plastic bag trick when necessary to take a break.
John,
From your response and MM's comment, sounds like I left the rough-outs too thick. My "chunks" are half logs a little longer than the diameter, ends coated with paraffin.
Al H.,
Mighty pretty pieces. Y'all students did well.
Al N.,
Thanks for your response! Was indeed considering turning the next chunk to "finished" thickness and see what happens. I do keep the piece wet while roughing, and use the plastic bag trick when necessary to take a break.
John,
From your response and MM's comment, sounds like I left the rough-outs too thick. My "chunks" are half logs a little longer than the diameter, ends coated with paraffin.
Al H.,
Mighty pretty pieces. Y'all students did well.