Need Opinions On Busted Tenon...

[BILL DONAHUE]

Finally got back to the PM3520B after about six weeks off and started off with a bust. A busted tenon that is. The piece was labelled as "cocobolo" when bought but I suspect it may be bacote. It's 7 3/4" wide by 3 3/4" high, with a 3/8" tenon. It has a thin crack along the bottom filled with a soft spongy stuff. When I started to hollow it the tenon split along the crack.

What should I have done different and is it possible to rescue it? Is there a guide for how thick the tenon should be for the size of the wood? Thanks.

[Bob Hallowell]

Bill use what ever you can to reverse chuck it and make the bottom flat the glue a wast block on to make a tenon. and that is definetly cocobolo.

Bob

[dave barnhart]

I'm just a novice at this, but...

Assumption- you have not hollowed out the bowl. If you can reverse chuck it or mount it on a face plate, then you can 'reshape' the bowl down to where you can make a new tenon. I've had a good amount of experience with that mistake. That and watching my 'glued to waste-stock" pieces fly off.

The size looked good, but that is a lot of mass to be spinning. Definitely use the tail stock to steady it while you finish the outside, and possibly turn some of the inside as well.

As to the imperfection... You can try to clean it out and refill with an epoxy/sawdust mix. I don't think that super-glue would penetrate enough to be effective.

To all: If I'm way out to lunch on this, let me know!

r/s
David

"The difference between amateurs and professionals is that the professional knows how to hide his mistakes better."

[Bernie Weishapl]

First thing I would do is to stablize that crack. If you don't you will continue to have problems. Been there. If you reverse the bowl and put a new tenon on I think it will break again. Some use CA but what I did was mixed 5 minute epoxy with DNA till it had the consistancy of milk. I then painted it on the crack after filling it with sanding dust and kept filling it till it wouldn't take anymore. I let that dry for 24 hrs. Then you can do like Bob or Dave said to flatten the bottom and use a glue block. Or you can reverse it if you don't have it hollowed yet and reshape the bottom for a new tenon. I have used both methods and the glue block seemed to work a little better.

[Steve Schlumpf]

Bill - for what it's worth I would do the same as what Dave suggested. You mentioned that you had begun hollowing when the tenon broke. I would remount the blank using the hole where you had started hollowing and reshape the blank. In the process of reshaping - and turning a new tenon - you may get rid of a lot of the cracked area that causes you concern. Once you have the new shape and tenon - then I would follow Bernie's advice and take care of what ever is left of the cracked area. Remember - it's just wood! Have fun - but be safe!

Looking forward to seeing your saved hollow form!

[Jim Becker]

Not Bocote....wrong color entirely. Cocobolo is plausible with that color.

Reverse mount it and cut off the tenon flat. Glue on a waste block and true it round as a replacement tenon. Finish turning the piece and then reverse again to trim off the tenon while you finish the bottom of the piece. Be sure that you get some epoxy or thick CA in that crack before you glue on the waste block so that things remain stable to the end.

[Chip Sutherland]

Looks like afzelia to me not cocobolo or bocote

[BILL DONAHUE]

Thanks for all the good suggestions. This is a geat forum and having solutions to problems is why it's so good.