Roughing out a Bowl - Long with pics
Bill Grumbine, Kutztown PA
>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.
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 �� 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.
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.
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.
Here you can see the shaving coming off the gouge. This is fun turning to the max!
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 �� bowl gouge.
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.
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.
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.
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 �� in diameter, so I am making the wall thickness 1 ��. 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.
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!
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. :)
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
