Results 1 to 13 of 13

Thread: large piece of walnut question

  1. #1

    large piece of walnut question

    I have been cleaning out the barn, (Per orders from the Mrs.) and finding things I totally forgot I ever possessed. Among some items in a rear corner, I found a very wide black walnut piece cut from the crotch of a black walnut. It is not a center cut, so there is no pith. It is only about 4/4 thick, but is about 30 inches across. I purchased it when I lived in Arlington VA 30 years ago, thinking I might make a table, but I realized it might be too thin, and I would probably never find a planer that wide. So, I can get a round for a very large platter. However, though the lathe has a swivel head, the lowest speed is 600 rpm, which seems far too fast for the outer reaches of something that large in diameter. My goal would be a final thickness of about 7/16

    Besides the speed question, since the piece is only 4/4, mounting something that large is the next problem. Glue a block of wood? Epoxy for something that big? Would a large shallow tennon be enough once the bottom side has been shaped?

    Is this a bit more than a newbie should try?

  2. #2
    Lots of "ifs" here!

    IF the piece is dead flat, your chances of getting a finished piece at around 1/2" thick are much better. Doesn't take a lot of cup or warp to remove that possibility.

    IF you have a secure way of having a toolrest positioned outboard, you may be able to try this.

    IF you have the guts of a suicide bomber, you may be able to attempt to rough out the rim of a 30" platter at 600 rpm!!!

    IF you get a catch, it is going to be catastrophic!

    IF you survive this, it may well be a miracle!

    Now, for some suggestions. First, I would not attempt to rough this out on the lathe you have. The rim of a 30" platter at 600 rpm is REALLY moving fast. It will need support or you are going to get a lot of chatter. I don't know if you have a OneWay bowl steady, but it can be rigged to provide some support to the back side.

    If you can find someone with a large surface sander you may be able to get it flat and smooth, thereby eliminating much of the "roughing out" part. Get it band sawed to as close to round as you can. I would use a glued on waste block to turn a tenon on. I prefer Titebond with my wasteblocks.

    This is a big undertaking for an experienced turner. You will need to assess the risk vs. the gain and make that decision. Personally, I would want a lot more support and material to work with in making a platter that large. Having an 8/4 or better blank makes for a much easier situation. It provides support for the whole project as one works toward the center. You have to get the rim completed first, preferably front and back, as the chances of going back to it without a catastrophic catch are slim.

    Left click my name for homepage link.

  3. #3
    Join Date
    Jan 2008
    Location
    Chicago Heights, Il.
    Posts
    2,136
    Ive been turning 45 years and have done quite a number of large bowls and platters. I agree with John that your chances of turning it are not worth the risk. The explosion of a piece of 30” walnut with a rim speed multiplied by 600 hundred rpm could pierce elephant hide. Just hitting the switch could send pieces flying. Much better to go the sanding route with maybe a routed edge.
    Member Illiana Woodturners

  4. #4
    I heartily second all of John's comments, especially his warnings.

    At 600 rpm, a point on the edge of a 30" disk would be moving at almost 8000 FEET PER MINUTE -- that's roughly 90 MILES PER HOUR. If the disk came loose from the lathe, let alone disintegrated, the result would be catastrophic. Even a fragment would have incredible energy.

    I have turned a number of thin platters 14"-16" in diameter from 4/4 material, after turning perhaps 150-200 or more smaller plates. Simply getting a 4/4 disk 16" in diameter to flat, with parallel faces, is crucial and not trivial. As soon as you then begin reducing the thickness, the edge begins to flex. The thinner the disk, the worse the flexing, which produces vibration. That increases the difficulty of safely making a cut and likely uneven cuts. Uneven cuts create further imbalance which exacerbates the problems.

    With initial disks even that 16" diameter size, I would begin the flattening at low rpm -- far below 600 rpm. It's been some time since I last turned a 4/4 16" disk, but I doubt that the maximum would have been 600 rpm at any time, if that. I was turning from the perimeter inward on BOTH faces in 1" - 1 1/2" increments. It was impossible to go back; I even sanded in increments. I could see the turned edge of the 16" flexing slightly by the time I was halfway to the center. I was turning thinner than 7/16.

    At 600 rpm a point on the edge of the 16" disk was moving at HALF the speed that a point on the 30" would.

    I think that the crotch aspect of the material might make the turning even more dangerous -- there would likely be differences in density in such a section. That would increase the likelihood of significant vibration simply from inherent weight imbalances from one area of the disk to another.

    I have two 4/4 disks 20-21" in diameter which I cut more than a year ago. Based on my experience with 16" disks, I have hesitated to begin. They remain unturned, though they are near at hand for turning "soon". Based on my experience, they are the largest 4/4 disk I would even think put on the my lathe although my lathe would allow larger over the bed. I don't know when, or even if, I might actually turn one.
    Last edited by Robert Henrickson; 10-01-2017 at 10:57 AM.

  5. #5
    IMO - the flex that will be in a 4/4 piece that large which hasn't been flattened and is an odd shape, will be huge.

    im sure it would make a great plate/platter but perhaps it's time to consider power carving.... I would go shopping for some Arbortech Tools. King Arthur tools makes an affordable chainsaw disc for an angle grinder that could also work well at hogging out the wood. Or a 30-50 grit sanding pad on an angle grinder would work, as well. But it would have to be done outside, I think.

    if you decide to turn it, send photos of your process... I'd love to see what you come up with. Just wear one of those outfits the bombsquad uses and you're good to go...

  6. #6
    Join Date
    Jan 2009
    Location
    Harrisburg, NC
    Posts
    814
    I can't add to the others but being the (practical) devil's advocate.....
    What the heck are your going to do with a 30" platter? I understand climbing a mountain just because it's there...
    You don't state the length. For me a large 18-20" platter and set of plates with with even smaller "shallow" bowls for salads would be great.
    Probably should have kept my trap shut. Sorry if I offended. You may well have a reason for a platter.
    "I became insane, with long intervals of horrible sanity." - Edgar Allan Poe

  7. #7
    Thanks for the warnings. and advice. I strongly suspected that 600 rpms would be far too fast. I do have access to an old cord wood shaft and bearings. If I can mount the piece on that and then hand turn against a router with a 1/2 inch round router bit. I believe I can rig a router holder on the cross slide of my old screw cutting lathe and mount the cord wood shaft perpendicular to the lathe bed. That way, the wood can spin at a half rpm and I still have control over the cut by using the cross slide and longitudinal feed. Just light cuts, no hogging things out. It isn't the usual sense of turning but it should work. There may be more than one way to climb Everest. gotta give it some more thought.

  8. #8
    Join Date
    Feb 2008
    Location
    E TN, near Knoxville
    Posts
    12,298

    make smaller things?

    Quote Originally Posted by Michael Mills View Post
    I can't add to the others but being the (practical) devil's advocate.....
    What the heck are your going to do with a 30" platter? I understand climbing a mountain just because it's there...
    You don't state the length. For me a large 18-20" platter and set of plates with with even smaller "shallow" bowls for salads would be great.
    As for size: I made a couple of "matched" platters for our home, one almost 20" and one closer to 15" I think (turned from 8/4 sapele). The 20" platter is almost too big - we rarely use it. We use the smaller one a lot. A large platter might be good for goodies when entertaining a crowd but we are not very entertaining.

    platters_two.jpg

    I might consider cutting a larger 4/4 slab into smaller circles or squares and turn some plates instead of platters. You could make a bunch of plates from that board. You might even be able to make a series that include the crotch flame. You can make some squarish plates shaped something like this with 4/4. This one is made from thicker stock and dished more but the basic shape makes great shallow plates. At maybe 9-10" across the turning is a lot easier and safer (and people love them!):

    penta_maple_ellis_IMG_5435.jpg

    Another thing to do is cut circles, flatten, and stack and glue to make thicker wood and make bowls or something. I've been making Beads of Courage lidded bowls/boxes like this. Some contrasting layers can be eye-catching. As coincidence would have it, I recently found three walnut slabs in my storage shed, forgotten for years after they came off my sawmill. One is 8/4 and will make some platters but I'll cut up the two 4/4 slabs to make smaller things. Besides gluing up a stack or making plates, 4/4 can be used to make hand mirrors, wands, conductor's batons, trivets, ...

    As for turning something like a plate from 4/4 I'd probably glue on a waste block to preserve wood, Tightbond would work.

    BTW, I didn't write it down first on paper as I usually do but if I kept the conversions straight in my head while punching numbers into my calculator a the circumference of a 30" disk would be PI*D or over 94". At 600 RPM the rim would be moving at over 53 MPH or 78 ft/sec. Someone can check the math. Decapitatingly (is that a word?) fast! It would scare me.

    JKJ

  9. #9
    I suppose a platter is the wrong term. I was thinking more of a round serving tray like waiters use but shaped more like a platter to use the thicker portion where the rim meets the flat for strength..Just seems a crime to cut it into smaller pieces. I'll have to invest some more thinking.

  10. #10
    Join Date
    Feb 2008
    Location
    E TN, near Knoxville
    Posts
    12,298
    Quote Originally Posted by Perry Hilbert Jr View Post
    I suppose a platter is the wrong term. I was thinking more of a round serving tray like waiters use but shaped more like a platter to use the thicker portion where the rim meets the flat for strength..Just seems a crime to cut it into smaller pieces. I'll have to invest some more thinking.
    That's probably as good a term as any. Dictionary definition of platter: a large flat dish or plate, typically oval or circular in shape, used for serving food.

    I used to worry a lot about getting the biggest piece possible from a piece of wood. For example, for over 10 years I've had some pieces of Cocobolo so big they are difficult to lift - I finally started cutting them up into small turning blanks, some 1" square. I saved big blocks of Bloodwood and some other exotics for years thinking I'd make some big bowls - I think some of these will meet the bandsaw soon. And a big slab of Mediterranean Olive now exists mostly as spindle turning blanks with a few pieces saved back for 10-12" plates/platters. I guess I finally realized I would probably never use some of this otherwise and when I kick the bucket it would probably just be sold for firewood. (And I enjoy turning smaller things more than big bowls.)

    Hey, have you thought about flattening and gluing two pieces together to get a thicker blank for the rim? Maybe cut away the center of one leaving a ring and glue that to the lower one that shows the best figure, glue on a waste block and basically turn the rim leaving the inside mostly flat. BTW, a drum sander like the Performax 22-44 is supposed to be able to sand/flatten a slab like you have (but I never tried it with mine). There are also large woodworking shops that could probably flatten it for you. But if there is any cupping it might come out pretty thin.

    Of course if you decide not to turn a large platter you might be able to sell the slab to someone who does want to make a table top, assuming it has stayed flat. Someone looking for a slab that wide may expect to pay top dollar!

    JKJ

  11. #11
    I have several dozen large pieces of black walnut stored on skids drying in a stall in the barn. (There are about 200 black walnut trees here on the farm.) Some of them are half logs (sawn in half lengthwise) 20 inches across. I have a few cords of stock for smaller plates, bowls etc. Just this one 30 inch piece. I will figure a way to shape it with out the dangerous speed. Thank you all for the thoughts and warnings.

    I have a large old fashioned sour cherry tree that needs to come down this fall. it is about 50 ft high and almost 24 inches in diameter. Allowing for sap wood, that still leaves some big wide pieces of wood.

  12. #12
    Join Date
    Feb 2008
    Location
    E TN, near Knoxville
    Posts
    12,298
    Quote Originally Posted by Perry Hilbert Jr View Post
    ...walnut... ...large old fashioned sour cherry tree that needs to come down this fall. it is about 50 ft high and almost 24 inches in diameter. ...
    OK, I'm coming to visit, I might accidentally pull a gooseneck trailer. I'll need to know which direction to drive from here.

    I need to take down a black cherry, a sugar maple, a persimmon, and some sassafras this fall/winter. I have big white oak (30"+) and hickory on the ground now and a big pile of cedar logs waiting until I fire up the woodmizer behind the barn. Isn't it a shame to have such a glut of wood compared to some of the country?! A friend visited from Arizona and couldn't believe the hardwoods here - she loaded her station wagon with slabs and boards until I was afraid the tires would burst! We do have walnuts on our farm but not many and nothing over 18". Lots of big poplar, some well over 3' DBH. (I don't fell for the wood, just when necessary and windfall)

    JKJ

  13. #13
    I ran ads for free walnut turning wood. Already cut up. Folks just had to come haul it away when I cut it and had no takers. I even offered to load up entire logs, if the folks had a trailer. I turned a piece of cherry at the last club meeting and folks wanted to know where I "got it" told them I cut the chunk from a stump on my farm and folks acted disappointed. I figured turners would be the ultimate wood scroungers. Apparently not. I hate to think of the pieces of wood that I simply burned before I started turning again.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •