From Log to Bowl     —     CWT- March, 2003

Safety-Number #1
Safety glasses, boots, dust protection
Sharpen all tools prior to starting
Common sense

Materials

• Any Back Yard or Neighborhood Tree will do (ask permission first!)
• Road Kill (Ask permission if anyone is around or if near a home)
• Chain Saw (know how to use one safely or get some help prior to attempting any chain saw activities
• Green wood sealer (if serious about the hunt!)
• Lathe & assorted tools

Starting the Bowl

• Prepare blank from log - layout and cutting off comers with saw
• Balance between centers
• Round edges down

If using a four jaw chuck:

• Start to form outside shape leaving a tenon toward the tailstock end to reverse the bowl on - be sure to cut a square shoulder where the chuck will hold.
• Do your sanding on the outside of the bowl Before you begin cutting the inside of the bowl out. (This is done because the bowl will change shape as you remove the inside of the bowl releasing the tension in the wood so the shape of the bowl will distort some making it difficult to sand afterwards.)
• Reverse to dear out the inside of the bowl

If using a faceplate

• -The blank will be screwed onto the faceplate on the side, which will eventually become the interior of the bowl.
• Start to form the outside shape of the bowl cutting down toward the tailstock.
  During the shaping process, create a tenon at the tail stock end that is at least as long as the screws you intend to use to attach the faceplate. (This is done so that the screw holes will not be seen in the finished bowl because you will cut this tenon off during the final reversing stage.)
• Note: Diameter of tenon is determined by size of faceplate to be used.
• Also, it is wise to form a small center cone or tenon (small enough to fit
  into the hole in the faceplate) in the middle of this tenon in order to re-
  center after the roughed bowl has had a chance to dry and distort.
  

• Most woods will cut differently between the end grain (vertical direction of the tree - top and bottom) and the side grain
• How to get cleaner cuts when cutting end grain
  • Use sharp tools
  • Use something to “raise the grain” - It is generally thought that you
    should either use water or use whatever finish you will be using for
    your final finish.
  • Use a technique called shear scraping
  • Use a cabinet scraper

Reverse the nearly finished bowl to finish the bottom:

• We never, ever, want to leave screw holes or any indication of how we
  held this bowl onto the lathe. So, in order to remove most, if not all
  traces of your methods, we reverse the bowl again at this point and
  turn the bottom of the bowl.
• You may want to use some kind of doth to protect the finished rim from
• scratching when reversing for the finishing cuts on the bottom.
  Methods:
• Jam chucking - use a waste block, cut a groove to fit the rim of your
  bowl in a snug fit (it needs to hold the bowl while you are finishing the
  bottom).
• Donut Jig - use a rubber covered wooden face plate with an auxiliary
  "donut" shaped ring that is held with screws to the wooden faceplate
  leaving the bottom of the bowl exposed for finishing (but held securely
  to prevent loss of bowl!)
• Cole Jaws - commercially available reversing jig for a four Jaw chuck
• Various other methods include, taping, hot glue, plastic "tape" (cling
  wrap or "flat tape) and even Styrofoam

To complete the bowl, complete the rounding of the bottom so that you create the
illusion that the outside shape flows through the bottom of the bowl. Cut some
sort of decoration into the bottom, a bead, a couple of grooves, whatever,
something to show that you actually finished the bottom.

Also, remember that you want to be sure that the very bottom of the bowl is
concave OR the center of the bottom of the bowl is not sitting on the table when
the bowl is. Why? You are working with a natural material that moves with the
weather, humidity, temperature, or “just because”. If you make a flat bottom,
the bowl will never sit flat, it will wobble. However, if you make the bottom
slightly concave, the bowl wilt sit on the outside edges of the ring and thus sit
much more securely and not usually wobble.

And that is that! Go cut down some trees and make the savings, er..., I mean
shavings fly!

• Do your sanding on the outside of the bowl BEFORE you begin cutting
  the inside of the bowl out. (This is done because the bowl will change
  shape as you remove the inside of the bowl releasing the tension in the
  wood so the shape of the bowl will distort some making it difficult to
  sand afterwards.)
• Reverse the bowl by screwing a faceplate onto the newly formed tenon
  and remounting the reversed bowl to the lathe to dear out the inside of
  the bowl.

Remove the wood from the inside of the bowl as demonstrated.
Tips to remember:

• Finish the rim before you move too deeply into the process of removing
  the center of the bowl (including sanding, as this will probably be
  impossible to do on the lathe afterwards.)
• Use thickness gauges to measure the wall thickness of your bowl as
  you cut the inside.
• Use a bowl gouge to give the chips a large flute to flow out of the bowl
  and out of the way.
• At the bottom of the bowl, in order to remove the “nipple” which often
  forms as we turn. Use an up and down motion very lightly with a round
  nosed scraper, directly at the center of the bowl.
• If you have a “dimple” problem, take Very light cuts away from the
  center of the bowl to smooth out the higher portions. (Practice,
  practice, practice.) Also, be aware of your wall thickness at this point
  because this is where the inevitable wall collapse or blowout happens!

Finishing

• Remember, do your sanding on the outside of the bowl Before you begin cutting the inside of the bowl out. You may even want to do your finishing at this point for the outside if you plan on a very thin bowl... but the finishing process can also be completed all at the same time rather than breaking this step up. (It’s personal preference and depends on the project as well.)
• Get the best finish possible from the tools
• When sanding, start with highest possible grade sandpaper, this will depend on how well your tool finish is
• Progress through grits 120,150,180, 220, 320, 400 etc. until you attain your desired finish level
• It is a good idea to sand with lathe on to start and then turn it off and hand sand with the grain between grades of paper
• Be sure to wipe the dust off between grades of paper, this will dear most of the grit from the sandpaper off also and will help prevent this grit from scratching further when the next grade is applied to the wood

Additional Resources:

CWT Library has many books and videos on basic bowl turning check them out!

For those of you with internet access, this website has pictures showing the process from a log to a bowl that you may find interesting and informative.

http://www.enter.net/-ultradacMogcutting.html

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