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Discussion Starter #1
I was just ready to flip this bowl and when I took it off the lathe to remove the woodworm screw I noticed my tenon had a void. The void looks to be deep and somewhat comes into my tenon, it makes me nervous since I've already lost one bowl off the lathe when the tenon broke due to a catch.

So my question to all is, would you proceed on? Fill the void with something?

All help is appreciated,

ForumRunner_20140117_202601.jpg


Cody
 

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Hard to tell from the pic but your tenon looks long/tall. Remember that it should not bottom out in your chuck, the chuck needs a flat shoulder to register against too. As for the void, I'd just turn carefully. Always wear a face shield and stand out of the line if fire.
 

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Discussion Starter #4
I should add that I measured the void and from I can see its a half inch square. I also just stuck a piece of copper wire almost a whole inch into it.... makes me seriously wonder what the surprise is on the inside.
 

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Well it depends on whether that is the bottom of your bowl or are you going to cut deeper so the void is gone from the bowl. I don't think the void will be a problem because of where it's located. I would think a tenon would break starting at the long grain portion. The void is located in the short grain section so I don't think it would be a problem.
However if that void is in the bowl what are you planning to do with it. That to me is the more important question.
 

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I'd fill the void with CA / superglue , the thin one .
I have on occasion , put in a squirt to line the void's edges , and then pushed in black tea leaves - glue - leaves - glue , tamping it as I go .
The colour of the mix blends in well with most knots and bark inclusions .

From what I can see , the old dead knot hole is not large enough to be a structural safety issue .

The photo below is of a 300mm dia. Red Alder bowl . The dark 'knot' at the 5 o'clock position is a CA glue + black tea leaves filler .

Most folks don't notice it ;)
 

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Discussion Starter #7
That was the intended bottom, I was just getting ready to start hollowing it. I don't have much room to make it any smaller and cut all it out.

I honestly have to plan for filling it either, maybe just hollowed and see what it looms like then.
 

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What John said. Since that is the planned bottom I would look at filling it with something. I do this so much now I don't think about it I just mix up whatever I decide to use and get it fixed so I can get it finished.

Good luck with it.
 

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Discussion Starter #9
Would some CA with some shavings I got work or would an epoxy be better? I got both just nothing for a filler beside the,shavings.
 

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That nothing I would worry if it traveled up the side of the bowl or down the base of the tenon fill the void after you get the bowl almost complete then fill with inlace of your choice.

Jerry
 

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I think sawdustfactory put his finger on a very important point -- the tenon must not bottom out in the space inside the chuck jaws. 7/16ths sounds very long, but it depends on the chuck jaws. Also, it's hard to tell from the photo if you created a truly flat shoulder around the tenon. The front ends of the jaws need a square resting place, that is a significant contribution to the stability of the piece in the chuck. (If it's square, the bowl has less chance to "flex" the tenon, which reduces both chatter and the opportunities for a nasty catch.)
 

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Discussion Starter #13
Optimally that is my goal when making a tenon, I try to make them as long as my jaws will allow. I feel the more bite I get the less nervous I am, this will be my 6th bowl or so. I primarily do pens and stoppers and so forth but am really getting into bowls now.

If my tenon looks strange it's because I noticed a small lip on the outer edge of my jaws so I make that part of the tenon a touch smaller so all the surface area of the jaw grips the tenon.
 

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I do this kind of stuff all the time. (check my photos if you want)
My favorite to use is 2 part epoxy with whatever coloring you want to put in--it takes 24 hrs to set, but does well with chisels. ( I buy the stuff that's sold as "pour on finish"- I just mix up enough to do the job--it's a 1:1 mix, just let it set for a little while if it's to thin to use at first)
CA glue I use sometimes, but you have to do it multiple times. Use the thin first to chase the crack and then get a thicker one so you have some matrix with your coloring agent. I like turquoise or malachite--but have used copious amounts of fine glitter too (don't knock until you've tried).
+1 on the tenon being right for the chuck--dismounts are no fun
Make sure to stay out of the "line of fire"-in case of failure
 

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Would some CA with some shavings I got work or would an epoxy be better? I got both just nothing for a filler beside the,shavings.
There are a couple of other things you can use that most people have on hand. I dry coffee grounds or tea after I make some then grind it down to add to my glue. On darker woods the voids almost disappear and on lighter woods it gives a nice contrast. Best part....free.

When you sand save good clean samples of each wood and put them into a small container to use for filler.
 

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I tend to make my tenons longer than most people, typically at least 3/8". I may make them shorter on dry hard wood. Almost all of my turning is with fog wood so it doesn't cost me anything to give up a very little in depth. My daughter was up over Christmas and turned about a 10" bowl so we used a tenon instead of a recess. She got a catch and it dislogded about 1/4" on one side but still held. If the tenon had been 1/8" or 1/4" it probably would have orbited.

My chucks are Nova and they actually state to use a longer tenon.
For the 50mm jaws they suggest 5/8", for deep jaws like the spigot jaws 1-3/16". The 50mm start on page 18 with the spigot length on page 19.
http://www.teknatool.com/products/chuck_accessories/Jaw_Sets/downloads/Accessory Jaws Manual.pdf

You did not state your brand of chuck so the above may not apply.
If it is a Nova and the jaws are smaller than 100mm they may have a lip on the interior and Novas states to Not cut a relief for the lip as it is designed to bite in. The width of the lip is only 1mm so it can bite into even very hard wood.
 

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Discussion Starter #18
Yes, I'm running a Nova. I did read that info before but must have missed the part about not cutting a recess. Thanks!

Well I found what was in the middle and it wasn't much. The boss (fiance) said she didn't want it filled so that's a bonus to me.



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I agree ---- that's a nice bowl!
 
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