# Segment Bowl Explosion



## johnchoponis (Jan 10, 2011)

Here is what a segment bowl looks like when it explodes. I was sanding the bowl when it happened, luckily I was standing beside the head of the lathe and not in front of the bowl. Still not sure why it made it through the turning process and exploded during the sanding process. I have made several segments in the past with no issues at all. It put a hole in the 1/2 OSB behind the lathe and one piece went threw the celling in the shop. This happened about 8 months ago and it took until now to work up the courage to try another one.

John


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## TCCcabinetmaker (Dec 14, 2011)

my guess woulod be a glue joint failure. Maybe something to do with the heat from sanding? Just guessing, but usually when glued pieces fail on the lathe it has something to do with either the wood itself, or the glue.


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## JollyGreen67 (Nov 1, 2010)

What was the RPM while sanding ? I found out the hard way not to exceed 500rpm while sanding - heat buildup will delaminate the glue.


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## tamboti (Oct 19, 2009)

Glue joint failure, seems from the pictures there is a lot of end grain joints,not good if not sized before glue up. Speed should be 500 or less. You do not say with what grit you were sanding/ The lower the grits more heat and if you were trying to remove tool marks you applied to much pressure. Regards Tamboiti


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## rance (Sep 30, 2009)

John, anything I could add would be pure speculation. Please tell us more about RPM's, glue type, glue process, etc. The more we know, the better we can hypothosize.


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## AddeCrom (Dec 1, 2012)

John, thank God you're not hit.
The exact cause is not clear, may be the use of old wood glue, not enough glue, not waited long enough??
Try it for yourself to analyze!


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## Knothead62 (Apr 17, 2010)

Glad you are OK. I find myself standing off to the side when turning.


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## marcuscraft (Nov 14, 2012)

Yikes. Images like this terrify and have kept me away from lathes to this point. Glad the walls and ceiling took the brunt of the hits and not you.


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## MonteCristo (May 29, 2012)

My guess is also higher RPMs during sanding, combined with a joint(s) that was ready to let go. It's happened to me too.


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## SCOTSMAN (Aug 1, 2008)

I nearly lost my thumb when a piece I was sanding after it was turned exploded and whacked right down on my thumb .Ten days in hospital and two operations later all is well but it also took a while for me to work up the nerve to turn again.It is worth it though don't give up.Just be extra careful. Alistair


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## Kreegan (Jul 10, 2012)

That's a strong argument in favor of those lathes that have a cage that comes down over the work. If a piece exploded like that on my lathe, I'd have glass raining down on me when it hit the fluorescent lights on the ceiling. Glad you're ok.


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## johnchoponis (Jan 10, 2011)

Sanding speed was 550-600 rpm. This was glued up as a traditional cutting board, left to dry for a week, cut into angle strips on the table saw and then glued back together, dried for another week, then cut into rings on the scroll saw then glued the rings together. After all of this the bowl set for another month before I got back to it. Tight Bond II is the glue I use.


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## ldl (Dec 4, 2011)

Sometimes things just happen with no explanation. Maybe all the cutting and reglueing was a factor.


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## mojapitt (Dec 31, 2011)

Glad you're not hurt. Always a scary situation.


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## BrandonW (Apr 27, 2010)

glad you're safe! I still think you should finish it, it has a very cool look to it in its broken stage.


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## rance (Sep 30, 2009)

My guess would be internal wood stress. I'm guessing that less time sitting may have made a difference.


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## marcuscraft (Nov 14, 2012)

Brandon has a point, it actually is a very cool piece as a little candy dish. I could see not wanting to go back to it after it failed like that. I would guess its about as fail proof as can be now though.


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