Post by pault on Sept 27, 2021 18:56:04 GMT
Hi
I just thought I'd share my technique for finishing the bottom of bowls, that is, the last phase of turning a bowl... (rather than the finish you might apply)
I have watched just about every YouTube video on bowl turning there is, and it seems starting a bowl is fairly easy. The main method is to mount the top of the blank on a faceplate and shape the main part of the bottom of the bowl whilst turning a tenon on the very bottom. You then turn the bowl around and put the tenon in the jaws of a chuck to then turn the rim and the interior of the bowl (having removed the faceplate of course
). The real problem then is how you remove the tenon and finish the very bottom of the bowl. There are a few options:
Kind regards,
Paul Tew
I just thought I'd share my technique for finishing the bottom of bowls, that is, the last phase of turning a bowl... (rather than the finish you might apply)
I have watched just about every YouTube video on bowl turning there is, and it seems starting a bowl is fairly easy. The main method is to mount the top of the blank on a faceplate and shape the main part of the bottom of the bowl whilst turning a tenon on the very bottom. You then turn the bowl around and put the tenon in the jaws of a chuck to then turn the rim and the interior of the bowl (having removed the faceplate of course
). The real problem then is how you remove the tenon and finish the very bottom of the bowl. There are a few options:- Use a 'vacuum chuck' to fix the interior of the bowl to your headstock
- Use a 'jam chuck' to pin the bowl interior and the bottom of the bowl between the headstock and a live centre in the tailstock
- Use 'button jaws' fixed to a chuck to grab the outer rim and hold it as firmly as you can whilst turning the tenon into a base.
- Use a 'Longworth chuck' in a similar way to 3.
- You may have a different method that is magical and/or I don't know about.
- I don't have a hollow headstock so I can't create a vacuum.
- I did this once or twice. Creating the right shape of jam chuck so as not to create marks on the bowl interior is a problem. Another is removing enough of the base material (the tenon) without the whole thing flying off the lathe is yet another. You will always end up with a nub that needs to be removed manually.
- Not too bad but I didn't have a 4 jaw chuck at the time...
- I decided to make my own Longworth chuck that could hold basic bowl shapes (incurved rims are still a problem though ) Here's a pic
I need to explain that this was the first time I had used a router hence the few 'wanderings' off line. The 'buttons' are rubber demijohn bungs. There are wingnuts at the back to tighten the whole thing down (and thereby expand the buttons) and to prevent any further movement. The diameter is adjusted by sliding the two plates in opposite directions when the wingnuts have all been loosened. - If you do know any magical spells that may fix my work to the lathe, please pm me
Kind regards,
Paul Tew