Mounting a bowl for bottom/foot cleanup

[Jerry Ingraham]

Hi Everyone,
I have posted several questions and have received great answers from all of you. I have ordered Bill G's dvd and am soaking up info like a sponge. I bought a Oneway Talon and am turning some small (6") bowls for practice. My question is, do most of you use a jam chuck or jumbo jaws to reverse your bowls to clean up the foot? So far my bowls are not even close to the same diameter so I would have to reshape my jam chuck constantly. I suppose that is to be expected. How are your jam chucks made? Just a piece of mdf or something more detailed? Thanks in advance for your help. i may have post a couple pics tomorrow if I can work up the courage!

[Jim Becker]

You really don't need to go to the trouble of having a flat jam chuck if you don't want to. Turn a block of wood round, either on a faceplate or with an appropriate tenon to use in the Talon or other four jaw chuck. Put a slight radius on it so it has no sharp corners. Now just use a piece of old carpet padding (the multi-color stuff) between the thing you made for your faceplate or chuck and the bowl or vessel. Bring the tail stock up to lock them together. It will take a little adjustment to get things running true, but you'll quickly become skilled at that. (Hint...you can use your tool rest with the base unlocked to help you judge centering as you spin things by hand. Once you have it turning true under "one hand power", snug up the tail stock a little more and clean off the bottom. You'll be able to get all but a little nub which is easily removed with a simple carving gouge and then lightly touched up with some 220 grit sandpaper by hand.

And do pay attention to type of center you have in your tail stock when you are doing this. You do NOT want something with a long point sticking out. Some folks even turn a little wooden cover to go over the live center if they don't want to invest in one that has just a minor "pin prick" of a point inside of a cup center.

[Carole Valentine]

Try the donut chuck Bill uses in his video. You can make a bunch of rings of different sizes. Get an extra face plate to keep mounted to the base of the chuck. Jim's suggestion is equally good. I use that rubber waffle stuff for padding. It gives good non-slip surface. I think I got an 8' roll of it in Sears tool section. It is used for toolbox liners, router and sanding mats, etc. I am a fairly new turner too, and I still have trouble getting things running true when rechucking!

[Richard Allen]

I use the "jumbo jaws" for cleaning up the bottoms of most bowl. I have always used this method and I find that I get good access to the bottom with htis method. I know many very acomplished turners who use jam chucks for finishing the bottoms. I have used jam chucks and that method works okay. I also have a vacume chuck which works okay on many woods but I will often turn wood thin and it is easy to colaspe a turning with a vacume chuck.

Whatever method you select it take a a few times to become comfortable with the process.

Good Luck

Richard

[Barbara Gill]

I use a vacuum chuck or the Cole jaws.

[Shane Harris]

You don't need to reshape your jam chuck everytime. Just make one with a slightly rounded face and pad it with a small square of foam or cloth. Run your tailstock up gently. Adjust your bowl until it runs true and tighten the tailstock.

Hmmm, the more I write, the more I'm wondering if I'm talking about something different. My 'jam chuck' is actually more like a drive center except that I turned one end to roughly duplicate a MT#2. Put in the headstock and use it in conjuction with the tailstock to hold the bowl between them. I'm sorry if that sounded confusing. If I'm not making sense, let me know. I can post some pics...

Shane

[Steve Inniss]

Jerry,
To answer your question, MDF is good mat'l for the jam chuck, and yes use your parting tool for a new size each time until it"s time to toss it. 2 thicknesses of MDF ie 1 1/2 lasts through lots of bowls and can grab some unweildy ones a little better.

HOWEVER, It's not worth doing it this way - too much unnecessary fiddling.
I, as Jim details above, have some of that lathe padding material glued to a 16" disc and use the tailstock to hold the bowl in place. I found it worthwhile to mark concentric rings with a pen on the stuff to speed the centering of the bowl on the disc.

-Steve

[Jim Becker]

Shane, "Jam Chuck" is used for more than one thing, unfortunately. I use your method, but others use a "jam chuck" that consists of a flat platter of wood that they turn a groove in to match the diameter and configuration of a bowl rim. No matter...having choices is a good thing!

[keith zimmerman]

I use a process similar to what Jim has discussed, except, my jam chuck is a piece of hard maple with a hollow center that I mount in my chuck. The hole gives it the shape of a ring. After I true up the face, I use an old piece of the thin mousepad rubber to pad the inside of the bowl. I then draw up the tailstock with a short point and place the point in the hole that was made when originally forming the tenon. Then, I follow the same process that Jim discussed.

If I wind up with no hole in the tenon, I use a small piece of wood on the live center and very carefully center the bottom of the bowl, then do what Jim discussed. Extra light cuts are required because it is very easy to knock a bowl off-center this way.

keithz

[Dennis Yoder]

An assortment of PVC couplings, unions, and reducers with closed cell foam glued to the end makes varied sized drives. The PVC is from the big boxes and the foam comes from the craft store. The drives fit over the chuck and can be tighted to run true. With the tail stock you can true rather quickly. The drives can also be used with a vessel with a very small mouth by resting upon the shoulders of the turning.

[Blake McCully]

Jerry,
Since you have a talon chuck already, spread the wallet for the mini jumbo jaws. You won't regret it. However, just like the other methods described, you'll still have to "fiddle" a little, changing all those little rubber donuts to get the proper expansion. Since I have been using my jumbos, that's about all I use.

Just my $0.02.

[Harry Pye]

Jerry,

Like Blake, I have the mini-jumbo jaws for my Talon. They work quite well but the downside is the time needed to switch jaws and to locate all those rubber buttons in the right set of holes.

On Bill Grumbine's video he shows an easy inexpensive way to finish the bottom of a bowl. Basically it is what a few people here have described: a padded lump of wood in the headstock and the tailstock pressed into the bottom. This way you can turn the bottom except for a really little nubin in the center. Bill takes that off on the lathe too.

[Jerry Ingraham]

Thanks everyone. I had ordered Bill's dvd last week and it showed up after I posted my inquiry. That is quite likely the most informative video I have seen. Kudo's to Bill for it. I saw the various ways to finish a bowl bottom and I do like the looks of the friction knob and tailstock support. I believe that is what I'll try first. Thanks again everyone!