Bowl coring question

[Jon McElwain]

So I have some seasoned bowl blanks in the 15-18" diameter range to core. My coring rig goes to 16 inches, but I can stretch it to 18 without too much difficulty. My question is, how many of you use a large diameter core to cut the outside of the larges bowl in a set rather than rough turning a blank to outside diameter. The rough turning takes a good deal of time with dry wood, and I would like to see about cutting this portion of the work out of the mix by turning a tenon on the bottom of the slightly out of round blank and cutting bowls directly out of it to a maximum size of just under the out of round diameter. I am not sure if I am explaining this well, but if you can picture what I am getting at, I would appreciate comments.

My concern is that a slightly out of round blank will have too much wood vibration to core very well. I suppose I could true up the blank a little bit, but the blanks I have are essentially half rounds, so unless I cut a bowl form all the way to the tenon, I will continue to have an off balance blank.

Whaddaya think?

[Steve Kubien]

I think I understand what you want to do and I would say, don't do it. Turn the outside as you would normally.

One thing I dislike about coring (the only thing) is how most of the cores are of a pre-determined shape. They can easily start to look manufactured, from a factory. I realize there is less chance of this with a McNaughton rig but still. Turn the outside to help avoid this.

My 2 cents.

[Grant Wilkinson]

I did it, but with a piece of wet wood. Roughing it would not have been too bad. I was just curious about how it would work. Essentially, the core was the first good bowl. I outer part was very thin and scrap. I put the piece between centers first and cut a good tenon it it. I chucked that up, trued the face, and cut a tenon into it so that I would have something that was already centered to hold it with after coring. With wet wood, it was slick. I don't see what it wouldn't work with dry wood. Just cut slower.

[Nathan Hawkes]

In my experience, coring dry blanks can be unpredictable. Sometimes they core quite well, without incident, and other times they vibrate like crazy despite being perfectly round, running true, etc. For me, most of the time the shavings get much hotter as well, but you can spray water into the cut with a spray bottle if need be. I just like using wet wood for coring.

[Harry Robinette]

I core allot of my bowl blanks but I wouldn't try to core the outside off on dry wood especially, I don't think I would do it with green wood ether.

[Thomas Canfield]

I don't core, but trying to core at a reduced speed due to the unbalance of a rough piece would seem to be a hinderance. Turning the outside lets you increase the speed quite a bit from my experience.

[Reed Gray]

I didn't totally follow your question. Were you wanting to core the outside part of the blank off rather than turning it off? I have seen some people do it that way. It can be done by mounting the bowl top side to the headstock, and then cutting off the outside. If the blank is unbalanced, you would not be able to get the speed up very high. I do not think it would be possible to do with the Oneway, but maybe. Probably easier and faster to rough the outside first.

robo hippy