Roughing out a Bowl - Long with pics

Greetings all

It has been a long, long time since I have posted one of my photo essays anywhere on the internet. I got involved on another forum in a discussion regarding tool rests breaking while roughing out bowls, and that inspired me to grab my camera and the lovely SWMBO when it came time for me to get on the lathe to rough out a very nice piece of ambrosia maple.

<img src = "http://www.enter.net/~ultradad/roughbowl01.jpg">

In this first picture I have the bowl blank slabbed and roughed round on the bandsaw. It is installed on the lathe with a faceplate and square drive screws. On a side note, this blank probably weighs close to 80 lbs, based on past experience. It is approximately 15” in diameter and 6 ½” thick. I am using a 4” faceplate and eight screws.

To rough a bowl with the best results and the most pleasure, it is essential to start at the bottom of the blank using a bowl gouge. I will first flatten the bottom of the blank to get a smooth surface. This allows me to see if there are any cracks or other defects that need to be dealt with before moving on.

<img src ="http://www.enter.net/~ultradad/roughbowl02.jpg">

In this picture you can see the flattened bottom of the bowl. You can also get a good view of the proper position for the toolrest when beginning the roughing process.

<img src ="http://www.enter.net/~ultradad/roughbowl03.jpg">

In this next picture, I have moved the tool rest so that it is approximately 45 degrees to the long axis of the lathe. This is so that I can begin to remove the corner of the blank and begin the curve of the outside of the bowl. Using a series of short passes, with each pass longer than the preceding one. I get the side smooth with a minimal amount of bouncing the gouge around. It is less wear and tear on the wood as well as the operator.

<img src ="http://www.enter.net/~ultradad/roughbowl04.jpg">

Here you can see the shaving coming off the gouge. This is fun turning to the max!

<img src ="http://www.enter.net/~ultradad/roughbowl05.jpg">

Here is a shot giving you the overall perspective. You can see the shape developing as I proceed up the side of the bowl. I am turning with a Glaser ¾” bowl gouge.

<img src ="http://www.enter.net/~ultradad/roughbowl06.jpg">

This is a closeup of the tenon being formed. Some of you guys like to use a recess. I like a tenon. It can be used as a foot, it can be turned away, but most importantly, it is almost impossible to crush it. Using a recess can crack the wood right in half if you are not careful.

To be continued...

I got a message saying I had too many pics in my post, so I broke it up into two. Boy I shore hope I don't get into trouble. :eek: I can see Ken getting into his truck with his tire tool and heading up to PA to smack me a good one...

<img src ="http://www.enter.net/~ultradad/roughbowl07.jpg">

Here we are at the top of the bowl blank. I am parting in with a parting tool to establish the rim of the bowl. This does a couple of things. In the first place, it defines the top of the curve on the bowl. That is important, as a curve needs to have its endpoints defined before it is refined. If not, the most beautiful curve can turn into something dumpy and heavy looking. Second, it removes the pith, cracks, and any unevenness at the top of the bowl.

<img src ="http://www.enter.net/~ultradad/roughbowl08.jpg">

Here is a shot of progress so far. The top and the bottom have been defined, and the bowl is ready to reverse for hollowing.

<img src ="http://www.enter.net/~ultradad/roughbowl09.jpg">

The bowl is flipped, gripped with a chuck, and the waste on the top is turned away so that a flat surface remains. The top is then marked for hollowing. The rule of thumb is to make the wall thickness 10% of the diameter. In this case the bowl is 14 ½” in diameter, so I am making the wall thickness 1 ½”. Since I am the proud owner of a Kel McNaughton coring tool, I do not have to turn the center into chips, but rather a smaller bowl. In this case I will end up with a bowl that is approximately 10” in diameter by the time it is finished. In other words, it is worth $100 to me at the current rate my bowls sell for. Here we see the KM tool set up and ready to core.

<img src ="http://www.enter.net/~ultradad/roughbowl10.jpg">

As a side note, the KM tool gets a bad rap from a lot of turners. Many people buy this thing and then claim that it takes the strength of Hercules to make it work. Not true. If someone is struggling with this tool, it is because they have failed to set it up properly. Here is a shot of me coring with two fingers, at a diameter of 10”+, at approximately 800 rpm. This tool is a joy to use when used properly. Coring time is about two to three minutes. Try and hollow out a bowl that fast!

<img src ="http://www.enter.net/~ultradad/roughbowl10a.jpg">

Here is an action shot of the shavings coming off the gouge while hollowing out! SWMBO got this one and then retreated to the far side of the shop to avoid being covered with maple. :)

<img src ="http://www.enter.net/~ultradad/roughbowl11.jpg">

Here is the semi-finished product. This bowl is ready for waxing and wrapping in paper. Alternatively, it can be boiled, frozen, soaked in soap, or any other of the arcane methods people have used to allegedly dry wood. My most common method is to paint the end grain with Anchorseal, wrap it in paper for a month or so, and then let it dry away from moving air or light for another six months or more. This one promises to be a beauty if it doesn’t crack. Speaking of cracks, there were a few small ones on the rim at the endgrain. I sealed them with CA glue.

If you have made it this far, congratulations! If you have questions or comments, I will be glad to entertain them.

Happy turning to all.

Bill

Awesome tutorial, Bill! The KM tool looks like both, a time saver and wood saver. Is it restricted to use on green wood or can one use it on dry woods, as well? Also, on the tenon; Is there is certain depth and width you make it in respect to the overall size of the piece? For instance, a certain % of the total diameter or such? Thanks again for a magnificent essay! :cool:

Quote:

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Originally Posted by John Miliunas

Also, on the tenon; Is there is certain depth and width you make it in respect to the overall size of the piece? For instance, a certain % of the total diameter or such?

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I'm not Bill, but I can answer this one!

Your tenon should be sized to fit your chuck :D ...but larger objects, such as the big bowl that Bill shows in his tutorial above, generally get a bigger one than small objects. This is also where the alternative jaw sets for the better chucks come into play...larger tenons require larger jaw sets.

I make my tenons only about 1/4" to 3/8" long and leave a "shoulder" for the jaws to snug up to. This insures that the chuck seats evenly around the turning. A big, heavy object would want a deeper tenon, but never have your tenon bottom out in the chuck.

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Originally Posted by Jim Becker

I'm not Bill, but I can answer this one!

Your tenon should be sized to fit your chuck :D

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Oh, a regular comedian, this one is! :rolleyes: OK, let me rephrase that part of the question: Does one make the tenon the LARGEST size available, which will still fit on one's particular chuck? (Before you come up with yet another smart-aleck remark, that would be the largest *without* exceeding the total diameter of said bowl!) :D

Seriously, I'm curious, because I'm one of "those" people whom Bill eluded to earlier and use a recess most all of the time, as opposed to the tenon. FWIW, you guys need to keep in mind I'm NOT running a huge Stubby or Poolewood and my blanks rarely go over 8 or 9" in diameter. Thanks for the tips! :cool:

Quote:

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Originally Posted by John Miliunas

Does one make the tenon the LARGEST size available, which will still fit on one's particular chuck?

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It's a judgment call, John. If it's a heavy piece (and you can put a heavy piece on even a small lathe) than a larger tenon is desirable since there is more "gripping area"...but this also brings to mind that having the right set of jaws on your chuck can be important to your comfort...the larger jaws will surround the tenon without having their sharp corners sticking out ready and waiting to smack you in the knuckles or catch your tooling when you get "close" to the chuck.

Quote:

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Seriously, I'm curious, because I'm one of "those" people whom Bill eluded to earlier and use a recess most all of the time, as opposed to the tenon. FWIW, you guys need to keep in mind I'm NOT running a huge Stubby or Poolewood and my blanks rarely go over 8 or 9" in diameter.

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I personally believe that using a tenon with a chuck is preferable, not only for a better grip and to avoid the chance of spitting the blank from the inside-out pressure, but also because it gives you more flexibility when you go to finish the bottom of the object. Since the tenon is "extra" material...you can turn off as much or as little as you want. When you use a recess and expand the jaws inside, you're a lot more committed to the shape you have in most cases, unless you're putting a whole lot of waste on the bottom. And if you are, you might as well use a tenon, anyway!

Thanks Jim. Sounds reasonable. And yes, I know you can mount pretty decent size blanks on a smaller lathe, but I've found that when I do this, it's way too easy to stall out the motor, especially as I get closer to the outside diameter. I keep my chisels nice and sharp, but it still happens. Yeah, I know, I'm probably being a bit too aggressive in my approach, but even when keeping a pretty light touch, you can see/feel/hear the thing slowing down considerably. :( One of these years, I'll have to upgrade the rig, but for now, me thinks I'll just have to settle for slightly smaller pieces. :cool:

Thanks for this great essay. As a beginning turner, I have about a million questions, and this has really been helpful. I have read a lot, but pictures are worth a thousnad words. Thanks for taking the time to post this.
Mark

umm, urrr, ugh,....D****! I really need to finish setting up my shop and get on that lathe! That is Awesome! Of course, I need to take a few lessons too. Cause I don't know diddly squat (are we allowed to say that?) about doing that kind of stuff but it sure looks like fun!

BTW, what's a SWMBO?

Congrats Bill, I'm hurt that we weren't the first to get this valuable info.... but I'll get over it.
Nice Live action seens.

Thanks guys. I'm glad you all liked it. It was fun shooting, and I had to be there anyway. :D

John, to answer your question, a lot of what Jim says is how I would respond. To take it a bit further though, for a functional bowl, I try to plan the foot so that it will be approximately 1/3 the diameter of the rim. The tenon will then be just enough smaller for a shoulder on what will be the bottom of the bowl that rests against the top of the chuck jaws. Artsy fartsy bowls are a different story, since the bottom may be a whole lot smaller. Then again, I am working on a bowl that is going to be 11" in diameter and have a bottom that is about 10" in diameter. this is a commission by a customer who gave me some very specific measurements. The tenon can be whatever I can get to fit in that case. I hope this is a good answer - if I missed something, let me know.

Bill

Thanks to both, Bill & Jim for the information! (Man, that's why I just LOVE this place!) I think the next bowl I attempt (Note, I said "attempt" :D ), I'll give the tenon method a go. But Bill, I still don't know about the MK in dry blanks. Will it work? Thanks again! :cool:

Sorry John, for forgetting that part. It works fine in dry wood. It might be a little bit bouncier, but set up properly, that is minimal. It is a bit dustier. Here is a picture of a bone dry piece of elm burl I cored with it. Not only was it dry, but those pointy things got in the way and made it even more exciting!

<img src= "http://www.enter.net/~ultradad/elmburl11.jpg">

Bill

Quote:

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Originally Posted by Bill Grumbine

Sorry John, for forgetting that part. It works fine in dry wood. It might be a little bit bouncier, but set up properly, that is minimal. It is a bit dustier. Here is a picture of a bone dry piece of elm burl I cored with it. Not only was it dry, but those pointy things got in the way and made it even more exciting!

<img src= "http://www.enter.net/~ultradad/elmburl11.jpg">

Bill

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Wow! Too cool! That's a way nice piece, Bill! Thanks much for the info. I think I really like the time-saving factor of it, which before, I never gave that much thought to. Keep posting those beautiful pieces! :cool:

Thanks a lot, Bill. Your presentation is totally outstanding!! Please do some dvd's for us. You are a good instructor and I hope Tauton or somebody picks up on it. I would buy your dvd in a NY minute!

Stan