I like to live dangerously. I often demonstrate square turning and will go as thin as 4mm so I can then steam bend them. Once you have done a few squares you don't worry about the corners. The method shown above is an excellent way of doing them if you are unsure. Excellently explained and good photos too.
If you feel like wasting wood you could do what Tracy Owen has done in a couple of his articles in Woodturning magazine - turn as normal and then cut a square out of the finished piece. He does this in the current issue.
I suppose that using his method you wouldn't have to worry about being so precise when you first mount the wood.
Nice one, John. Must admit I like the square bowl look but those whirling corners have always put me off. Sheesh, might have to actually make a bowl now, dammit. ](*,)
Hi, John:
Very nice photo sequence. It would definitely be safer doing it that way. It would also stop the chipping out at the edges although that may not be too significant since you have to dress the edges again after cutting off the filler pieces anyway.
In regards to finding the chucking recess from the wrong side, one method I have used was to inlay a disk of contrasting wood to cover the boo-boo. It is still obvious from the bottom that the repair was unintentional, but at least the bowl is rescued from the waste bin.
Your recess is larger in diameter than this one, so a disk of a single species of contrasting wood might not work too well. You could glue up a decorative disk of some sort or even find a glass or ceramic coaster that would turn the error into a "feature".
Oh dear, I think I'm a Philistine. Although I really like square bowls, I actually prefer this one before the 'waste wood' was taken off. Having said that my biggest problem in trying the square bowl has been to get the wings (as I think of them) turned without chipping them.
Pete
The best way I've found to avoid chipping is to turn up the speed as high as I can whilst still feeling safe and to put something of contrasting colour to the wood behind low down so I can clearly see where the edge is.
Also a useful technique when turning natural edges
Bob, I like the square lidded bowl, very nice. I will probably do as you show and fit a contrasting piece in the botton of the bowl. It is on the coffee table in the lounge filled with the Grandaughters chocs at the moment so the hole doesn't show.