Bowl Tenons in Soft wood?

[timf67]

Hey turners, I have a question and I apologize in advance for not having pics! Anyway, a friend of mine gave me an offcut of some 16/4 kd red cedar that he used to make a really nice table top. So I decided to cut it into a couple of small bowl blanks for practice. Things started well, the tenon turned easily and I shaped the outside of the bowl with no issues. I removed the bowl from my woodworm screw and chucked up the tenon. I started on the lowest speed (~400 RPM) and within a few seconds of starting to flatten and hollow the middle of the bowl, the tenon sheared clean off of the bowl base!:swoon: I almost couldn't have cut it off any cleaner. I would loved to try again, but I wanted to entertain suggestions on how to avoid the same fate on round 2...

 

[FredP]

I've had that happen with cedar.:gar-Cr it holds better with a recess. :icon_thum

 

[DaveO]

I have always been a fan of chucking with a recess, especially if you dove-tail it a little. That will provide the mechanical hold even if the chuck jaws get a little loose. Cedar is a very soft wood, and easily split. Using a tenon leaves you subjected to the fibers crushing and then what is there left to hold.

Dave

 

[Kalai]

If you still have some thickness to your bowla nd it is not over 6" or so in dia then sand the bottom and use ca glue and glue a wast block of another wood so you can chuck up to it again. Aloha.

Kalai

 

[Trent Mason]

Tim,

I actually had a recess crack on me recently, while working with 10 year old cypress. It cracked a little and I ended up taking millions of very light cuts to hollow it out. :swoon: If you're working with soft, bone-dry wood, then I'd use a recess, as mentioned before. And make sure you have plenty of "meat" or bulk around it, aka, a wider/flatter bottom.

My only turning lessons were at DaveO's place and he knows his stuff. :icon_thum He likes to use recesses and that started me down that path. After watching a few dvds that skeeter lent me I decided to try a tennon. I'd say the biggest mistake that I made starting off was making the recess/tennon to deep/long. Now, I use both, depending on what I'm working with. I'd have to say though, that for bowls, especially larger ones, a recess is the way to go. :thumbs_up:thumbs_up

Man, you're getting me motivated to go to the wood store and and scrounge around/beg for some scrap. :gar-La;

 

[Robert Arrowood]

Tim,

I actually had a recess crack on me recently, while working with 10 year old cypress. It cracked a little and I ended up taking millions of very light cuts to hollow it out. :swoon: If you're working with soft, bone-dry wood, then I'd use a recess, as mentioned before. And make sure you have plenty of "meat" or bulk around it, aka, a wider/flatter bottom.

My only turning lessons were at DaveO's place and he knows his stuff. :icon_thum He likes to use recesses and that started me down that path. After watching a few dvds that skeeter lent me I decided to try a tennon. I'd say the biggest mistake that I made starting off was making the recess/tennon to deep/long. Now, I use both, depending on what I'm working with. I'd have to say though, that for bowls, especially larger ones, a recess is the way to go. :thumbs_up:thumbs_up

Man, you're getting me motivated to go to the wood store and and scrounge around/beg for some scrap. :gar-La;

:widea: Trent, man don't go to the woodstore:no:.Check the want adds in the newspaper and find someone that sales firewood.No telling what you might find there.

 

[CarvedTones]

Or wait until next weekend and what is now TD-2 might drop some wood in Trent's lap...

I am another recess fan, though that is largely driven by experience with chucks that aren't exactly top of the line.

I also have used the face plate and glued to a waste block, still using a tenon into a very shallow hole made on the lathe to ensure it is centered.

 

[timf67]

Thanks everyone, I tried out the recess approach last night and it worked great!:icon_cheers

I was able to put a lot of pressure on the piece with the chuck and I was also able to take heavy cuts with no issues. Just a little more to go today and it'll be finished:eusa_pray