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Thread: Just a novice turner, having trouble with deep bowl

  1. #1
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    Just a novice turner, having trouble with deep bowl

    I'm just getting into turning after a long break. I got this burl maple (kind of spalted) I turned the outside with not much problem; but hollowing it out is giving me trouble. I just cant get a bowl gouge in the bottom of the bowl. I tried my crown hollowing tool, but it's grabby and leaves a pretty crappy finish. Not to mention chattering. I'm leaving a sort of natural edge.

    IMG_5334.jpgIMG_5336.jpg
    Where did I put those band aids?

  2. #2
    That looks like a great piece of wood.... on deep bowls I sometimes use my full size Easywood carbide tools to get the job done... https://www.leevalley.com/en-ca/shop...ull-size-tools

  3. #3
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    You do not give size of piece or depth of bottom that would help reply. On a shape like that, I would normally take it down in segments of about an inch or less especially until down to full support of wood without edge. The presentation of the bowl gouge would need the handle across the bed to get good start and then ride the bevel on way down rotating handle when deeper to maintain bevel. A different grind might also be needed to be a "bottom feeder" to do the bottom. The size of bowl gouge needed will also change with deeper bowl. I would guess your piece is possibly in the 6"D size but do not recognize lathe. I do not use carbide tools but a large half round nose scraper might be used to do the bottom. Hollowing the burl might also work better with a scraper and then a carbide tool would work well. Nice looking piece of wood and nice outside. HOpe you finish. You might want to sit it aside and practice on another piece that you are willing to practice on and end up with scrap.

  4. #4
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    I'm far from an expert, but can you tell us what size tool you are using and how far off the tool rest you are cutting? Your problem sounds like a combination of not having the bevel on the wood and being too far over the rest. As Thomas mentioned, you may do better with a bottom of the bowl gouge, which is nothing more than a bowl gouge with a bevel angle of upwards of 70 or 80 degrees. It will allow you to keep bevel support while making the transition from the wall to the bottom and moving along the bottom.
    Grant
    Ottawa ON

  5. #5
    I am also far from expert, but would agree with being creative about getting a tool rest into the bowl as close to the work as you can, and using an appropriate tool (Bottom-of-the-bowl gouge or round-nose or half-round scraper; the more extension off the tool rest, the heavier/thicker/stiffer you want the tool...), but also consider YOUR positioning. Does your headstock slide, so you could move everything down to the end of the lathe and stand in front of the work (instead of having to lean over the bedways)? Alternatively, could you pull the lathe out from the wall so that you could stand on the back side of the lathe for working on the inside of the bowl?

  6. #6
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    Do you have a scraper? I almost always resort to a scraper for bottom finishing. On the very bottom use a sheer angle on the scraper. Hard to maintain on the edges. Use a freshly sharpened scraper and light light cuts. Carbides will work exactly the same, but a rougher finish.
    And then there is the "new" world of Negative Rake Scrapers. They can give a exceptionally smooth and tear out free surface.

  7. #7
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    Quote Originally Posted by Dueane Hicks View Post
    I'm just getting into turning after a long break. I got this burl maple (kind of spalted) I turned the outside with not much problem; but hollowing it out is giving me trouble. I just cant get a bowl gouge in the bottom of the bowl. I tried my crown hollowing tool, but it's grabby and leaves a pretty crappy finish. Not to mention chattering. I'm leaving a sort of natural edge.
    These days I usually use one of the Hunter carbide tools. These are not like the flat-topped carbide tools and can cut like a gouge and can leave a better finish. There are heavy tapered shaft version in straight and swan necked to get inside the opening if needed. John Lucas has videos on several of the Hunter tools.

    I agree that a good negative rake scraper would be good for smoothing the inside once you have it hollowed (and on the outside). I also like the Sorby with the teardrop scraper like comes with this: https://www.rockler.com/robert-sorby...g-tool-rs200kt
    I used to use this tool (or more often, the swan-necked version, for both hollowing then switch to the teardrop scraper for smoothing inside.

    JKJ

  8. #8
    On the bowl outside, and on the inside sides, generally I use a 1/2" bar diameter "parabolic" flute shape bowl gouge with a 40 degree bevel. Minimize the overhang of the gouge beyond the tool rest, and swing the gouge handle sideways as necessary so that the bevel just below the cutting edge is gliding along the just cut surface.

    The transition zone or area is where the more or less vertical (inside) bowl side changes to the more or less horiontal bowl bottom. Often, it is more or less an arc of a circle. As the gouge bevel moves along the just cut surface (towards the bowl bottom) the bar of the gouge will get close to and may eventually hit the bowl rim. This lifts the bevel just behind the cutting edge off the just cut surface and the result is as you describe.

    As mentioned above, one solution is a second bowl gouge with a steep bevel angle (mine is 70 degrees) ground by simply rotating the gouge against the grinder, so that the cutting edge is perpendicular to the length of the gouge. The steeper bevel angle moves the handle away from the bowl rim when the bevel is gliding along the just cut surface, so that the bevel can glide down the remainder of the transition zone and across the bottom.

    If the "bowl" is really a hollow vessel, with an opening much smaller in diameter than the sides, then a carbide cutter may be necessary. I have no experience with hollow vessels.

    A local woodturning group can be a tremendous asset - demonstrations, question and answer sessions, and often mentors. Look for an AAW affiliated group in your area by clicking the Chapter link on the home page of the American Association of Woodturners, and enter the name of your state.

  9. #9
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    Thank you all, you have been very helpful!

    The diameter of the bowl is about 7 inches, with the opening at 6 inches. Part of the problem was getting my tool rest at the right position without getting my hand tore up on the burl edge! This lathe (Laguna 18/47) has a miss-machined banjo. The supposed 1" post hole, is 1" on the top and less than an inch two inches down inside.
    I'm also have trouble getting the tool rest angled inside the mouth of the bowl, so the gouge is 6 inches from the bottom of the bowl. I ended up using the crown hollowing tool, and a gl1 negative rake scraper to finish up. The wood is very crumbly, and will not shear off, but comes off in tiny chips. I got it done, but it shouldn't have been that hard to do! I have two gouges, a Hurricane cryo 5/8, and a 3/8. Both are sharpened to a swept back grind.
    Where did I put those band aids?

  10. #10
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    Quote Originally Posted by Dueane Hicks View Post
    ...The wood is very crumbly, and will not shear off, but comes off in tiny chips....
    For crumbly/punky wood I treat with several coats of thinned sanding sealer, (or thin CA glue) then make a light cut, then retreat as needed. This "glues" the fibers in place so they don't crumble or tear out so much.

    JKJ

  11. #11
    I have always wondered how to solve the punky wood problem. Thanks for posting that info.

  12. #12
    Join Date
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    Minwax Wood Hardener works great on punky wood also.

    https://www.minwax.com/wood-products...-wood-hardener
    My Dad always told me "Can't Never Could".

    SWE

  13. #13
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    Quote Originally Posted by Ken Schleman View Post
    I have always wondered how to solve the punky wood problem. Thanks for posting that info.
    The thin CA glue works faster but is expensive. I once used two bottles on one bowl which was beautifully spalted but so punky as to be unturnable. I've also used it to stabilize pieces where the fibers would come out in chunks with my thumbnail, for example this little vessel. The whiter part would crumble at a touch and almost fall out if you looked at it too hard. The finished surface is hard and smooth.

    LiquidAmber_comp.jpg

    When applying CA it's best to go easy and apply many times until the wood won't take any more. If too much is added at one time the exothermic reaction can make it hot enough to smoke. Also, too much CA at a time in one spot can make it bubble and form a hard crusty white substance which is a pain to deal with.

    If there is just a small spot or two of tearout I learned a trick from John Lucas - wet sand with thin CA! Use 220 or so paper, apply the thin CA to the paper, then sand that area. It pulls sawdust from the immediate area and mixes it with the CA and forces it in the void. It usually blends very well witht he surrounding wood. There is a an opportunity to glue the sandpaper to your fingers but it seldom requires surgery.

    I did not have success with Minwax wood hardener. Maybe I wasn't using it correctly or maybe I got some bad stuff. I used (wasted) two cans on one project.

    JKJ

  14. #14
    Quote Originally Posted by John K Jordan View Post
    ...When applying CA it's best to go easy and apply many times until the wood won't take any more. If too much is added at one time the exothermic reaction can make it hot enough to smoke. Also, too much CA at a time in one spot can make it bubble and form a hard crusty white substance which is a pain to deal with.
    JKJ
    I could barely handle the obnoxious fumes from most CA glues until I tried some non-fuming varieties from PARFIX sold by woodturner/demonstrator Mark Sillay. I've now become a big fan of the PARFIX 3408 'Wicking Grade' & 'Low-Blook' CA Glue with a long open time (40 seconds). The long open time means this glue doesn't have a big exothermic reaction like many other faster setting CA glues, and it makes it easy to wipe off excess CA glue from the surface in order to prevent a plastic like finish. Mark Sillay gets PARFIX by the case so his prices are about the best.

    -Karl

  15. #15
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    Quote Originally Posted by Karl Loeblein View Post
    I could barely handle the obnoxious fumes from most CA glues until I tried some non-fuming varieties from PARFIX sold by woodturner/demonstrator Mark Sillay. I've now become a big fan of the PARFIX 3408 'Wicking Grade' & 'Low-Blook' CA Glue with a long open time (40 seconds). The long open time means this glue doesn't have a big exothermic reaction like many other faster setting CA glues, and it makes it easy to wipe off excess CA glue from the surface in order to prevent a plastic like finish. Mark Sillay gets PARFIX by the case so his prices are about the best.

    -Karl
    I agree, that is in fact some great glue, quite well behaved! I bought a case too for club members and me.

    When I use "normal" CA in quantity goggles keep the fumes out of my eyes - a must for me even with good ventilation.

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