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Trouble Undercutting Bowl Rim

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narrowboater

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Hi Guys

I am having trouble undercutting the rim of a bowl. The first two pics show the bowl and the mess I am making of the inside. The third pic shows the tools I have tried. As you can see it started off as a natural edge bowl, but the natural edge is disappearing at a rate of knots, and the interior is woeful, I keep having catches. I realise that the bowl is now a write off, but would like to understand what I am doing wrong, and use it as a practice piece. Any advice would be appreciated.

Regards
Rod

PS I wiped the blood off before I took the pics.
 

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CHJ

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I take it you did cut the lip of the bowl to final thickness with a bowl gouge as you went and removed the central core in stages the deeper you went?
Scrapers and the like are not going to work effectively if you have removed the support for the outer edges and the bowl starts to deform as the stresses relieve.

Work the natural edge to final thickness as you go and never come back to it once material removed.
 

Blister

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Rod

I would suggest you try to undercut the rim on a standard bowl first

as you have chosen a difficult piece to practice on and the type of bowl needs to be approached with caution

the bowl you have shown will give a ticking sound each time the tool contacts a solid edge , so you end up with a cut / no cut / cut / no cut situation

at this time what normally happens is you push the tool too far into the gap and BANG / Blood etc :lol:

Try it with a std bowl first , you will need to lean over the lathe bed a bit to get the correct tool angle of approach , or if your lathe will run in reverse turn from the other side ( BUT BE careful the chuck does not undo and come off )
 

narrowboater

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CHJ, thanks I think you are right, I finished the edge thickness and then set about removing the middle, trouble is I caught part of the rim with a tool, and had to remove the damaged part, I then had to go back over the interior of the rim and things got progressively worse Thanks for the help. Another lesson learnt, I hope.

Blister, thanks, I think you are also right, bit off a bit more than I could chew. Just put it down to experience. How goes the boating? PM sent

Regards
Rod
 
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