>During the 5 years I have been turning I have attended Symposiums, taken a class at John Campbell, participated in chats, joined a turning club and read hundreds of posts. During all of this I have neither seen a dried roughed out bowl re-turned nor have I read how other turners do it. At least I don't remember the discussions. I have come up with my own way but I really would like to know how others handle re-chucking the dry bowl and turning it. Maybe this would also be a good topic for the chat.
>I use a compression chuck, which I refer to as the Grumbine chuck since he taught me how to make one, to retrue the tenon (if it needs it, which it almost always does). After truing it, I simply chuck it and turn it to the finished thickness. Then back to the compression chuck to turn off the tenon and finish the foot.
>Vac chuck or if it`s too distorted,use the vac chuck drum to drive it with the tailstock in place and true up the tenon.Chuck it by the now trued tenon and turn as usual.
I like to mount the bowl between chuck and live center. Base of bowl to the tailstock. I then true up the tenon. Mount the oval bowl in the chuck and true the face of the bowl. Then true the first inch or so of the outside followed by truing an inch or so of the inside. At this point the blank is running pretty smooth and I bring the speed up to turning speed.
I then barely true the inside and out. I marks the #1 jaws on the tenon and set the bowl aside for a few days. I want to see if it is going to change shape any more. I figure I have waited a while for the bowl to dry. I can wait a few more days to be sure everything is stable. Sometimes this part of the process is repeated several times.
>Barbara, I use a variety of jam chucks in the chuck to fit the bowls, and use the tail stock. (I don't recommend this to everyone, but many times I just use the bare chuck jaws. You need to have a lot of faith in your equipment with this approach.) Only the really volatile woods require much more than that. I orient the bowl such that I need to remove the least material, which is coincidentally the place where you have the least vibration. I begin be truing up the outside to get approximately round, and don't waste too much time trying to get a superb cut, since many times the orientation in the chuck will be a bit different when it's reversed. I clean up the tenon last, in case the bowl has shifted during the cleanup of the outside.
Then I reverse the bowl in the chuck, true the rim, and final true the outside, shear scrape if necessary, then do the inside. Sand the parts you can get to, then definitely use a jam chuck with a sanding pad circle against the sanded inside surface (if you don't have a vacuum chuck), and the tailstock, and finish off the bottom, sanding all but the center. Carve off the center nub from the tailstock, sand the area left, oil it, and put it on the sales shelf.
I know a lot of folks retrue the bowl and let it sit for a while before final turning, but I personally have never seen the merit in it. If the blank is dry, I simply have never seen it move appreciably. YMMV, of course.
>When I turn the green bowls I make sure to leave a dimple in the center of the inside; the outside center is marked with the live center. I had been using the spur center held in the Stronghold jaws to anchor the inside and the live center holding the base to true the tenon. Using just the jaws for the inside sure was easier. Thanks for putting me on to that trick. I like the idea of the trial to see if the bowl will move. I tried that today also.
>This thread will rapidly disappear under subsequent threads. Thanks everyone who participated. It was interesting to read how others are doing it. Dick, I will see you tomorrow night.
>Barbara, I have a very quick and easy system. I attach a glue block to my blank, rough turn it, wax it and let it dry. I use a screw chuck. To remount the vessel when it's dry, I merely put the piece back on the screw chuck and start turning. Her's a pic of about 70 rough turned pieces, nearly all mounted on a glue block.
>Yes, if you're using a wood that is very wet and tends to distort a lot that can happen. I turn mostly maple, myrtlewood, mesquite and madrone. Of those, madrone is the only one that'll give me problems, unless it's been boiled or steamed. Not too difficult to true up the bottom and install a new glue block.
If you want to try using glue blocks I can give you some useful info.
>Glue blocks can be made from most any dry wood that isn't oily. Not plywood, though. Might separate. However, since you have to part the piece off, a softer wood is best. Some wood, such as fir will split more easily than others. I use 5/4 alder. It's soft, doesn't split easily, and best of all, doesn't warp, so it's always flat and true. For you right coasters, poplar works well.
