Chuck recess at bowl bottom broke

[Jon Finch]

I was roughing out a bowl from the box elder haul I got today and had the bowl fly off my chuck. I had seen a video on youtube of a guy doing pull cuts while hollowing out a bowl so I decided to give it a try. I eventually caught an edge and it caused the side of the mortise(?) at the bottom of the bowl to break off (see picture of the bottom of this bowl). Any suggestions on how to get this bowl back on the lathe and centered? I've pretty much cut past my chuck bolt hole on the top of the bowl (see other pic). How would you get it back on the lathe?

[Kirk Miller]

Jon,
If your not going to treat the wood better than that We will have to come and confiscate it.....Just kidding. I am not sure what to tell you on how to get it back on the lathe. Do you have enough left to put it between centers and turn a new recess?

[alex carey]

Put it back between centers with a spur drive. This time make a tenon. Also, when you are hollowing the bowl, keep the tail stock in as long as you can.

[Leo Van Der Loo]

Why the heck would you do pull cuts on a piece with all the knots in there ??, push cuts is called for.
Right now you could turn a piece of wood that will fit into the recess and glue it in or return between centers, and make it a little shallower with a deeper recess.
You could have used a tenon and broke that off also, it is not the recess but the wrong cut you are doing, you are pulling the wood away from the chuck, while a push cut doesn't do that, still you should take care with wood like this. HTH

[ROY DICK]

Jon,
Jam it between your chuck and tail stock (revolving center), tighten and turn another recess or tenon, and rough the outside, remove and use ca glue on the recess or tenon.
Then continue on with sharp tools and don't try to hog it out.
This is not the only way, just the way I have done it in the past.
Keep us posted and good luck with the save.

Roy

[Alan Trout]

I would also Jamb the bowl between the chuck and live center and then turn a tenon of appropriate size for the jaws and continue to rough the bowl.

Good Luck

Alan

[Steve Schlumpf]

Jon - I would put it between centers and turn a tenon. If you notice - with your recess you do not have very much wood there on the outside of the recess to support the piece - making it really easy to blow out on you.

Looks like you have enough wood left to create a tenon and reshape the outside of the bowl before hollowing. I would stick with normal cutting techniques until you have a lot more bowls/turning under your belt. Some of these cuts work for the person doing them and look really cool but they have developed their skill to the level where they can perform the cut with no problems. As Leo stated - a pull cut on your bowl - while it can work - will most likely result in a nasty catch and a launched bowl!

Have fun with it and remember to play safe!

[Sid Matheny]

You could always use cole jaws and the tailstock and LIGHT cuts to make a tenon. Then remove the tailstock and face off the tenon.

Sid

[Ted Calver]

Jon,
What kind of jaws do you have on your chuck? Its hard to tell from your picture whether your recess was a dovetail recess or not. If you have the straight jaws, they don't work so well in a recess.

[Jeff Nicol]

Make sure when you cut that recess that the wood around it is solid. What no one had mentioned so far is that the part that let go was "BARK" ! The picture clearly shows that the area that is missing is from the outside of the burl and where it let go is right at the cambium layer, very weak area and it would have fallen off anyway as it dryed. So make sure you have solid wood for the jaws of the chuck to grab onto and you should have little trouble.

On the pull cut I use it all the time on wood that is full of curl, wild grain and burl, but I use a tool that can be controled to take small cuts and won't catch very easy unless you try to cut very deep. Of course it is my drill bit tool, but I have mastered it and stand by it's great function on end grain and wild grain blanks.

All the answers on how to get a recess or tenon back on the bowl are good, just use the one you have access to.

Stay save,

Jeff :cool:

[Jon Finch]

I think it was just late last night when I posted and I wasn't thinking :o. I put it between centers this morning and turned a tenon and finished roughing it out. No further issues other then it'll be shallower then I first intended. So do you guys prefer tenons rather then mortises at the base of your bowls?

Ted, I've got a Supernova chuck and the original mortise was dovetailed. I think Jeff's right too in that it was that area just below the bark (but I loved the white color ;)).

Re: pull cut. That was the first time I'd ever tried it. I didn't start out wanting to do it, it just "happened" and it worked so nice on the first 4-5 pulls that I just kept doing it... then the edge caught.

Thanks everyone!

[Curt Fuller]

Good save! And that looks like it's going to be a beauty of a bowl. Looking forward to seeing the finished product.

[art san jr]

Yes, good save, and thanks for sharing .... excellent lesson for the newbie here.


Thanks, Art.

[Bernie Weishapl]

Nice save on that one. That is going to be a nice bowl. Just be careful and measure. By the way I use a tenon exclusively. Never had much luck with a recess.

[Thomas Canfield]

Using CA will help beef up recesses or tendons in weak wood structure and help prevent the failures. Bark or punky wood with CA is still weak, but much stronger than plain weak wood.

[Reed Gray]

I use the recess exclusively, and have learned through trial and error what will work, at least for me.

One, on your recess, you start to curve away the side of the bowl right from the edge of the recess. I will keep a flat there for the foot of the bowl. On the bowl size you have there, I would want 1/4 to 1/2 inch of shoulder before starting the outside curve of the bowl. Depth wise, 1/8 to 3/16 inch. Also, if your jaws, closed, are 2 inches wide, they you want your recess to be at most 2 1/8 inch diameter.

When I first looked at the spot where it failed, it looked like the wood split off along with a grain orientation direction, kind of diagonally. If there was any bark in that area, that is a weak point, and while it held for general turning, the catch provided the extra stress needed to cause it to fail. Some times if it is wood that has broken, you can glue it back up and remount. I prefer the yellow glue to the CA. It just holds better, and let it sit over night. The remounting is never true, and you will have to even up the outside of the bowl again. CA glue can add a little strength to bark, but it is a patch job at best, and never secure for high speeds or aggressive turning. Any bark in a recess or tenon is a serious weak point.

I use scrapers for all of my roughing. For me, it is the most effective tool. It is much easier to do a push/pull cut with it on the inside of a bowl that it is with a gouge. With roughing cuts, push/pull, uphill/down hill doesn't really make much difference as you are just getting waste out of the way. It does not make a good finish cut unless you have it at 45 degrees doing a shear cut. The only way I would use a pull cut on the inside of a bowl would be if I was doing an end grain bowl, and that is the proper cut to use then. The problem with a pull cut on the inside of a bowl is in the transition area from the base to the wall of the bowl. When you hit the wall, you can have considerable more steel into the wood all at once, and get over powered, which causes the catch. The same can happen with a gouge if you go from having mostly the nose into the wood, then suddenly getting the wings into the wood. Too much steel in contact with the wood again. It does look like there is one deeper cut closer to the bottom of your bowl, but doesn't really look like you have much of a transition area developed yet, so I am not sure what caused the catch.

Being a master woodworker is being able to cover your mistakes, or if all else fails, destroy all evidence.

robo hippy

[Richard Madison]

Reed,
When turning cross grain with a recess, do you align the grain with the chuck jaws in any specific way?

[Reed Gray]

I don't really worry about that. With a really close fit, you have metal on the wood all the way around the recess, so pressure is pretty even. On a tenon, especially if you are stretching your jaws out a bit, you can end up with 2 jaws on end grain, and two on side grain. The end grain won't compress as much as the side grain, so your hold can be more uneven, so rotate it 45 degrees to solve this problem. Probably wouldn't hurt to do this as well on a recess, but I usually don't bother.

robo hippy

[Richard Madison]

Thanks Reed. I usually use a tenon, and on cross grain pieces I do align the grain with the gap between jaws as you suggested.

[robert baccus]

I would refain from trusting an "inny or an outie" on the bottom of a very soft and weak wood such as box elder, aspen, willow, ect. the foolproof way is to use a glueblock. these will hold even on very spalted wood. i glued on a 6" glueblock to a 110# green sweetgum vase lately. hollowed the inside as well. nothing but thick CA. try it.---------ol forester:D

[Leo Van Der Loo]

Here are a couple of pictures of some of my bowls with the recess showing, this is my usual way of holding my roughouts for turning the inside of them, all done without a tailstock.