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Thread: Grain Direction for Bowls

  1. #1
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    Grain Direction for Bowls

    Is there any rule of thumb concerning which direction grain (growth rings) should run when turning a bowl. I am attaching a picture.

    Is it best to have grain run so that the rings are cupped upward; sort of following the outside shape of the bowl?

    Or is it better to have rings facing downward or toward the outside of the bowl (like a frown)?

    Are there upsides and downsides to both?

    Or does it depend on which the turner thinks will look best? (Hope it's not this choice since I have no idea.)

    rsz_unnamed.jpg

  2. #2
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    Personal choice, when there is no sap wood and heartwood. When you look into the bowl, pith on the bottom will have rings, bark to the bottom (the way your picture is oriented) the grain will be "broken", not in rings. more like )( versus (). IF I remember correctly. I can never remember this answer.
    If you have 2 similar blanks turn one each way and label them. At the least you will learn what grain direction while cutting will feel like. Maybe I should do that so I can remember.

  3. #3
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    When the top of the bowl faces the pith, you will get peaks coming in from two sides.
    When the top of the bowl faces the outside of the log, you will get concentric rings.
    Veni Vidi Vendi Vente! I came, I saw, I bought a large coffee!

  4. #4
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    I had a billet of butternut large enough to get two 8" bowls 4" tall. It was cut perfectly for bowl turning with the pith having been centered above the billet. I turned one pith up and one pith down to see the difference. While the pith to the bottom gave a pleasing set of concentric rings, the bowl was very plain. The bowl turned with the pith toward the top presented a very dramatic set of cathedals on two sides and the bottom was beautiful with side to side cathedrals.
    As with any turning YMMV.
    Retired - when every day is Saturday (unless it's Sunday).

  5. #5
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    Quote Originally Posted by Randy Heinemann View Post
    Is there any rule of thumb concerning which direction grain (growth rings) should run when turning a bowl. I am attaching a picture.
    ...Or does it depend on which the turner thinks will look best? (Hope it's not this choice since I have no idea.)
    Randy,

    Green or dry wood? If turned green and allowed to warp there is some difference in the final shape. Also, a bowl turned green with the bottom close to the pith might be more likely to crack at the bottom depending on several factors, such as the thickness of the bottom, how close to the pith/juvenile wood, and the stability of the species or specific block of wood.

    The appearance of the rings varies widely and depends not only on whether the pith is at the top or the bottom and how close the pith is to the top or bottom, but on the radius of the bowl and in the case of the bark side down, how closely that radius follows the radius of the rings (smaller, larger, or close to the same). But in general, these pictures might help. I've seen better illustrations but these are the only ones I could locate just now.

    bowl_orientation_in_log.jpg
    https://www.pinterest.com/pin/493144227934039289

    bowl_orientation_jpg.jpg
    https://www.pinterest.com/pin/9710955429449644

    JKJ

  6. #6
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    Quote Originally Posted by Thom Sturgill View Post
    ... turned one pith up and one pith down to see the difference. While the pith to the bottom gave a pleasing set of concentric rings, the bowl was very plain. The bowl turned with the pith toward the top presented a very dramatic set of cathedals on two sides and the bottom was beautiful with side to side cathedrals.
    I have seen that too - some dramatic "hourglass" shapes on the inside of the bowl. The shape and position depends on how even or wild the rings are along the log and whether they are perfectly parallel to the base or if the slab was cut on an angle to the pith.

    These two shallow platters (from the same slab of sapele) were turned with the pith toward the top, bark toward the bottom. I didn't photograph with the intent of showing the pattern, but I can still see the hourglass figure on the top one, the bigger one similar but wilder since it was not centered and the figure was not even. The shallow convex shape of the bottom did not, of course, match up with the radius of the rings.

    Since the wide rims are convex from the top, it might be possible to see the oval patterns characteristic of what you see in the bottom of a bowl when the pith is towards the base.

    platters_two.jpg

    (Thanks to Frank Penta for this wood)

    In general, because of this I prefer to turn with the barkside down. But for a particular blank, things like any distinctive figure in the wood also need to be considered (x-ray vision would help here!). I chose the pith side down orientation for this one on a guess that the ovals would make a more dramatic and interesting background for the strong fiddleback figure in the maple:

    penta_maple_ellis_IMG_5435.jpg

    BTW, the slight angle of the ovals axes to the squarish edges was on purpose in an attempt to keep the piece from looking too "static". Jury is out on how well that worked...
    (Thanks to Ellis Walentine for the piece of wood.)

    JKJ
    Last edited by John K Jordan; 07-25-2017 at 9:29 AM.

  7. #7
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    Thanks to those who replied. Very helpful. Mainly I just wanted to be sure there were no reasons I wouldn't want to turn either way. The wood is dry. I haven't attempted any turnings with green wood. I am new to turning and find that there are a lot of things I don't know about wood when it comes to turning. Although I've been a woodworker for many years, I didn't start turning till about 8 months ago. So far, I'm sorry I didn't try it sooner.

  8. #8
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    Nice explanation and supporting graphics John!
    RD

  9. #9
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    Quote Originally Posted by Randy Heinemann View Post
    The wood is dry. I haven't attempted any turnings with green wood. I am new to turning and find that there are a lot of things I don't know about wood when it comes to turning. Although I've been a woodworker for many years, I didn't start turning till about 8 months ago.
    Don't get in too big a hurry to turn green wood bowls! I have read and heard from several turning experts that if you want to build expertise, start with spindle turning. (From Richard Raffan, Jimmy Clewes, Mike Darlow, Keith Rowley, Frank Penta...) It turns out that spindle turning will teach you the fine tool control that will let you turn anything. It apparently doesn't work the other way. Compared to spindle turning, I find turning bowls pretty easy.

    Frank said in the "trades", traditional turning apprenticeship in Europe, a turner had to spend maybe a year or so and become an expert in spindle turning before he was allowed to to start learning face/bowl turning.

    When I start beginners the first tool in their hands is a skew chisel. We learn how to make planing cuts with the skew in less than 30 minutes. Since the skew is the simplest and most basic edge, it's the best way to really understand the relationship of the bevel to the cut. After the skew, we work on the roughing gouge and then the spindle gouge. Since with spindle turning the grain is longways on the lathe, it also provides a more uniform wood for the beginner instead of the alternating side and end grain of a face turning.

    I have seen the opposite over and over - someone starts on the lathe and is seduced by the joys of turning green wood - easy cuts, big shavings flying - and never learns the fine tool control to make very light, controlled cuts that need minimal sanding, or turn thin and delicate things. But I know some people who only turn bowls and couldn't turn a spindle if they had to. Don't misunderstand - I'm not saying there is anything at all wrong with this - as long as the person is having fun and happy to turn bowls more power to them.

    If you want to learn more about wood and how it behaves and read, the book "Understanding Wood: A Craftsman's Guide to Wood Technology by R.Bruce Hoadley" https://www.amazon.com/Understanding.../dp/B011SJ8HCO
    I read this when I started turning (along with a few others) and it helped me a lot. I still refer to it often along with Hoadley's other book, "Identifying Wood"

    JKJ

  10. #10
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    John, Thanks for the advice. I started turning now because my wife is a polymer clay jewelry artist and got the idea to inlay polymer clay in turned wood bowls. Because of this starting point, my main interest for now, is bowls. I don't find spindles very interesting. I have no doubt you are right; namely that turning spindles develops a wider range of skills. I really enjoy woodworking of all kinds and never turned until now because, frankly, I was intimidated by it and really like making other pieces a lot. I find now that I enjoy turning very much and like the fact that, to some degree, the final design of a bowl may not be exactly what I envisioned to start with meaning I am sort of creating as I go. That isn't an experience I get when I make furniture or cabinets or even a cutting board (or the custom cribbage board I made for my daughter recently). So, while I like turning a lot, it, so far, hasn't become something I do exclusively. I'm very satisfied with my improving skills with small bowls and am taking my time moving to larger ones. I bought a midi lathe that will handle 12" diameter bowls and sort of sorry I didn't buy a larger one because I can see that, at some point, I will want to turn something larger than that. However, I'm a long way from having the confidence to do that, so I'm very satisfied moving at the gradual pace I am. I do always appreciate the great advice I've gotten from turners on this forum. Every time I've asked a question, I've gotten a solid, useful answer in a helpful way. Thanks again.

  11. #11
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    Randy, I am a big advocate of practicing your bowl turning by using 2x6 construction lumber. It helps you read the grain and shows the difference of pith up or down, and the extreme difference between soft/hard grain will make you a better sharpener. Sharp tools are the key to satisfaction with your turning. I find scraps at building sites when rafters are installed, and end up with a wide selection of grain pattern in the 2x6 material. You are not creating any masterpiece, but after about 6 of same shape, you can definitely see improvement in both quality and also confidence. Lots of different shapes and techniques can be practiced in that manner. My normal preference is to have pith down if the pith is centered to get the grain rings. If it is off-center, then the grain pattern is not uniform and then best use of wood.

  12. #12
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    Thomas,

    I appreciate the suggestions. I find, however, that I lose interest very quickly when I do something repetitively. It just doesn't hold the same interest and value for me. I have found that, after turning 9 bowls and 2 classes with an instructor who was very helpful, I have been improving steadily. Each bowl is a different shape so far and, for me, that's what kind of keeps it interesting. I haven't found anything yet that really has challenged me enough to just take some scrap and practice, practice, practice. About half my bowls have been made of scrap I would have shown away anyway so, if they would have self-destructed, it would have been no real loss.

  13. #13
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    Something else to consider, you can almost always get a larger diameter bowl if you orient the pith at the top, with the bowl shape mirroring the log shape.

  14. #14
    I learned bowls first and continue to struggle with fine cuts that don't require sanding. So there is some wisdom in Johns words.

  15. #15
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    Is it best to start with one species of wood and stick with that for a while before moving on to the next?

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