PDA

View Full Version : Remounting Rough Turned Bowl So I Can Turn Outside Without Tailstock



Paul Heely
08-13-2019, 6:55 AM
I've been watching a lot of Stuart Batty videos and would like to experiment with the 40/40 grind and his push style cuts. One thing I've noticed in the videos I've seen is he's turning a solid piece of wood and when cutting the outside he can create a tenon in the face of the bowl and then remove the tail stock and have unencumbered access to the outside of the bowl for cutting.

I have a bunch of roughed out bowls and would like to try some of his cutting techniques, but am a a bit stuck on how to remount a roughed out bowl without using the tail stack. Normally, I'd use the tail stock and a jamb chuck to get a clean tenon turned on the bottom of the roughed bowl blank, then mount the blank in a chuck and turn both the outside and inside while mounted by the foot. That won't work in this case because I would not have the needed access for the push style cut that I've seen Batty use.

Thoughts and ideas?

Paul

Roger Chandler
08-13-2019, 7:05 AM
Have you tried Cole Jaws or a Longworth Chuck? Mostly they are used for reversing the bowl with the bottom area exposed for final cuts to take off tenon or finsh off the bottom. You could also make a donut chuck, called also a Straka chuck.

Paul Heely
08-13-2019, 7:10 AM
Have you tried Cole Jaws or a Longworth Chuck?

No, because the roughed out bowl blank is warped and out of round so it won't sit correctly in those jaws.

Jerry Lear
08-13-2019, 10:01 AM
Vacuum chuck

Paul Heely
08-13-2019, 10:15 AM
Vacuum chuck

Same basic problem as the Cole or Longworth, the bowl is still just a rough out, so nothing smooth to get a good vacuum on. I suppose I could true up the foot of the bowl, then put in a chuck and true up enough of the inside to put my vacuum chuck on. Hadn't thought about it that way.

Let me ask a different question. For those of you that use a "traditional" bowl grind, how do you mount your rough turned bowls after drying so that you can get push cuts on the outside of the bowl?

terry mccammon
08-13-2019, 10:37 AM
I do exactly what you just posted. Job one is to mount between centers, and form a tenon, and work on the area near the tenon that I could not get at when a chuck is in place. Then mount in the chuck and proceed. I use a vacuum chuck to finish the bottom.

Prashun Patel
08-13-2019, 10:44 AM
I have seen someone finish the outside almost completely using a jam chuck + tail stock. When the nub gets small enough to split under pressure of the tail stock, they used painters tape to secure the bowl to the jam chuck, then removed the tail stock, sawed off the nub, and gently finished the bottom with a bowl gouge.

I usually saw off the nub and true it up with a router plane off the lathe. That is for me the quickest.

Often when truing up the roughout, I may flip it 2 times, truing up the foot and inside a little at a time until I feel confident I can get a good, concentric, secure jam and scroll chuck hold. I suppose you can do the same until you feel good about the vacuum chuck too.

John K Jordan
08-13-2019, 11:04 AM
Paul,

If I understand correctly, you can start with what you do now: turn a bottom tenon with tailstock support. Then make a way to hold securely by the top. One way:

- reverse the blank and hold by that bottom tenon
- flatten the center of the top as needed with the help of tailstock support as long as possible
- turn another tenon or recess in the top (I prefer a recess or better, drill a hole for a screw chuck)
- reverse and mount the piece by the top
- clean up the bottom tenon if needed
- turn the outside

Then hold by the bottom tenon and turn the inside.

I turn most bowls and platters somewhat like that - make a holding method in the top, mount and turn the bottom and the outside, then reverse and turn the inside. But instead of a tenon I often turn a recess on the bottom and decorate around it so I can leave the recess in the bottom. Besides saving time, this way lets me turn, sand, and apply finish to completely finish the bottom before reversing, requiring no vacuum, jam chuck, or cole jaws. Here are the bottoms of some done this way:

414330 414331 414332 414333

JKJ

Paul Heely
08-13-2019, 11:46 AM
That sounds like a workable solution. Was kind of hoping for fewer steps, but as I read through the ones you list, it seems that is how it has to work for what I'm trying to do. Thank you.

John Hart
08-13-2019, 6:20 PM
Nice foots John. I'll have to steal your ideas :)
Personally I like the jam method with the nub.
But if you have plenty of meat in your rough out, you could probably turn a tenon inside the bowl to work on the outside and get it round for the Cole jaws.

Jeffrey J Smith
08-14-2019, 12:13 AM
another option - ( ala R Raffen) - put the dried roughout in the chuck - by the slightly out of round tenon (it should run true enough to turn a small dovetail recess inside to reverse it on the same chuck (tower jaws help here, or use the largest jaws you’ve got to hold as far down into the roughout as you can to allow access for the chuck key) use the recess to hold while the tenon is trued and the outside is brought to shape. Reverse to finish the inside. The hold on the recess is surprisingly strong even with jaws relatively wide open. I don’t use the tailstock, but there’s no reason you couldn’t; just haven't seen the need.

That’s how I do the vast majority of my twice turned bowls - haven’t lost one yet.

Paul Heely
08-14-2019, 6:31 AM
The Raffan method sounds like just what I'm looking for. I'll give that a shot.

mike ash
08-14-2019, 8:15 AM
Great technique John! On a side note, can you give me some specifics on the ink pen you are using to sign your bowls? I haven't been happy with the ones I have found lately.

Thanks, Mike

John K Jordan
08-14-2019, 10:12 AM
I tried a LOT of different pens. This is what I use now:

Faber-Castell Pitt pens, black, wallet, set of 8
https://www.amazon.com/Faber-Castell-FC167137-Wallet-Assorted/dp/B005HF562K
414393

These use a black pigment instead of a dye which is not affected by the solvents in finishes. This set has various sizes, good for small and larger work.

The ink can still be rubbed off if not careful. To avoid that I do this: either leave an area unfinished until signed (easy to do with the recessed ring in the bases) or more typically, knock off any gloss from "danish" oil on just that spot using 600 grit paper and steel wool. Sign, let the ink dry well. Then I carefully apply a thin coat of oil over the lettering with a fluffed-up cotton q-tip or a small roll of torn paper towel. The idea is to avoid rubbing the ink. Once that coat of oil dries over top the ink, I can add a couple of more coats without having to be so careful, then perhaps go over it lightly with 0000 steel wool that I usually use on the whole piece.

The recessed ring in the base makes a protected kind of a shadow box place to sign, another think I like about that method of working. If the surface in that ring looks slightly different than the surrounding wood it is not objectionable.

JKJ

Reed Gray
08-14-2019, 11:54 AM
I don't do the twice turned bowls, but if I did, I would probably use the jam chuck and tail stock, true up the tenon, then start the outside of the bowl with a pull cut. Getting room/access for the longer handles with the tailstock is problematic. Once the tenon is trued up and you can easily use the 40/40 grind for going down the walls. but it doesn't go through the transition at all. I guess you might be able to do a push cut with a 60 degree bevel, which does work, though I find it better for transition and across the bottoms of bowls.

As for pens, I tried a new one from Sharpie since my local store stopped carrying the Faber pens. No identification on the pen, just the packaging, which is long gone. They said it was quick drying and wouldn't bleed through paper. It does not run or fade like the regular Sharpie pens.

robo hippy

Alex Zeller
08-14-2019, 4:52 PM
I use my Cole jaws. If the rim of the bowl is too warped to sit flat then I use my electric plane or homemade disc sander to remove the high spots so it'll sit flat. I often will only use four of the blocks (vs all 8) to hold the bowl if it's too oblong. Since I'm just trying to make the tenon or mortise round it works without problems for me. In the future, now that I've remade my disc sander I'll use that to flatten the rim every time.

John Hart
08-14-2019, 8:03 PM
As for pens, I tried a new one from Sharpie since my local store stopped carrying the Faber pens. No identification on the pen, just the packaging, which is long gone. They said it was quick drying and wouldn't bleed through paper. It does not run or fade like the regular Sharpie pens.

robo hippy

I agree...been using the new sharpies with good success. I just ordered the Faber pens to do a comparison

Jeffrey J Smith
08-14-2019, 8:17 PM
The Raffan method sounds like just what I'm looking for. I'll give that a shot.
While you’ve got it by the recess, true up the face/rim at the same time. I usually turn down both the inside and outside of the rim - about 1/4” down is plenty to see how much wall thickness is left to work with when its round...

mike ash
08-15-2019, 12:03 AM
Thanks John! I'll give those a try..................Mike