finishing bowls

[ahoiberg]

well, i'm finally prepared to try out a bowl. question regarding the finish...

i figure with the technique i've decided to use, it will be hard to finish it while on the lathe... i.e. if i have to put the foot back into the chuck to finish the inside, won't i damage the final turn i just accomplished on the foot? maybe i'm missing an obvious solution to this problem like using a cloth to wrap around the foot or something before chucking it a second time?

or would i just save myself some headaches with finishing it by hand off the lathe? any suggestions on a nice oil finish? i've heard some good things about liberon oils but haven't purchased anything yet, thought i'd get some input from the masters...

thanks!

 

[David Somers]

well, i'm finally prepared to try out a bowl. question regarding the finish...

i figure with the technique i've decided to use, it will be hard to finish it while on the lathe... i.e. if i have to put the foot back into the chuck to finish the inside, won't i damage the final turn i just accomplished on the foot? maybe i'm missing an obvious solution to this problem like using a cloth to wrap around the foot or something before chucking it a second time?

or would i just save myself some headaches with finishing it by hand off the lathe? any suggestions on a nice oil finish? i've heard some good things about liberon oils but haven't purchased anything yet, thought i'd get some input from the masters...

thanks!

Andrew,

An easy solution is to reverse the piece to finish off the foot and use a friction chuck to do it. Basically a friction chuck consists of a scrap of wood you turn to a shape that will fit nicely inside your bowl. Its base end is held with your 4 jaw chuck or a face plate or whatever is handy and quick, perhaps with a hunk of cheap 1/4 inch thick polly foam from a craft shop to cushion the face that contacts the inside of the bowl. The tail stock would have something like a cup center in it that won't dig into the foot. You apply just enough pressure from the tailstock so that the friction of the contact at the headstock holds and turns the piece. While in that position you can apply a finish to the outside if you want. Then, when you are ready, use light cuts to turn off the foot. I like to do it with a modified detail gouge that I ground to a spear point, cutting the foot down to a cone that has its point against the bowl. Then, when I have the cone tip about as small as I can make it without breaking off on its own I position my tool for a final cut, more of a gentle push really, and hold it in place with one hand. I turn off the lathe with the other hand and quickly move it into postion under the bowl, and then with the other hand push in and cut that cone tip. The bowl will drop gently into your hand. It won't go flying off into the void. The tiny mark left by the cone tip being cut is easily sanded off by hand.

David Ellsworth showed us that trick on a tour he made through here last year. It is handy and easy.

Sometimes, if I have a piece I am really afraid I might bobble when it falls off the lathe I will cover the bed with a soft fabric layer, or some foam if there is some handy. That way I don't accidentally nick it if I miss my catch. Has not happened yet though. Just indulging my paranoia.

you can make a friction chuck to hold a normal open bowl form from the inside, or hold a hollow form from the outside. I generally save the friction chuck shapes I make for this since they come in handy later on when a similar shape returns to the lathe.

I am afraid I don't have any photos of this to share. Perhaps others who use this techinique have a shot of it in action?

Dave

 

[Charlie Harley]

I usually sand the bowls on the lathe but apply an oil finish off the lathe. It's just my preference. Maybe it's a carryover from cabinet making.

I also use the previous post's method of reversing a bowl to turn off the tenon.

For almost all my bowls I use General Finish's Salad Bowl Finish. It goes on evenly and creates a pleasant, durable finish. On occasion, if it's a show piece that won't be used for salads or other heavy use, I'll set the buffer to it and really make it shine. :cool2: I wouldn't have thought an oil finish could take a shine like that, but it's really pretty when completed.

 

[ahoiberg]

thanks guys. i was planning on turning the inside with the usual tenon method on the foot and then reversing it using my big jaw chuck with the protective nibs on it... i think what i'll do is sand on and finish off. the friction chuck sounds like a great idea, but i don't think i'll attempt that quite yet...

i guess i should have mentioned that this won't necessarily be a food-use bowl. any other suggestions for oils?

 

[Rob Wallace]

Andrew:

thanks guys. i was planning on turning the inside with the usual tenon method on the foot and then reversing it using my big jaw chuck with the protective nibs on it... i think what i'll do is sand on and finish off. the friction chuck sounds like a great idea, but i don't think i'll attempt that quite yet...

Next time you come back to Ames to visit your parents, visit my shop and I can show you a variety of methods of reverse chucking bowls, including Cole Jaws, jam chucks, vacuum chucking, etc. ....I've done many of these methods over the years. Now I rarely do anything but vacuum chucking, simply because it's the fastest and easiest method for me. (Just don't come to Ames while I'm at the AAW Symposium in Portland!)

i guess i should have mentioned that this won't necessarily be a food-use bowl. any other suggestions for oils?

Multiple coats of Watco with ample drying time in between coats has worked well for me, as has tung oil. These oils, coupled with the Beall Buffing system produce a very nice finish. Boiled linseed oil works for some turners, but occasionally does not dry completely to a hard finish in some woods, leaving the surface a bit 'soft' and dull; I don't use it as a final finish. I also have used Mike Mahoney's walnut-oil based finish for bowls that were being used for food.

You can experiment a bit to find the best finish that works for you. Don't give up on other finishes like padding/friction shellacs (e.g. Mylands Friction Polish or Behlen's Woodturners Finish) and sprayed lacquers. There are lots of options.

Rob Wallace

 

[ahoiberg]

i don't have the beall system, but do have a kindof homemade buffing rig. i've only got a white diamond wheel. does beall use tripoli, white diamond & carnauba? i guess one buff with white diamond would be better than nothing?

 

[David Somers]

i don't have the beall system, but do have a kindof homemade buffing rig. i've only got a white diamond wheel. does beall use tripoli, white diamond & carnauba? i guess one buff with white diamond would be better than nothing?

Andrew,

The tripoli is the coarser of the two grits. Buffing with only white diamond only will help, but may not get rid of larger scratches. Worth doing though. Go really light with the Carnuba on your buff. Folks first using this stuff tend to overload the buff. You normally would rev the buff up and just touch the carnuba to it for a second. That is plenty to do a modest sized bowl.

Dave

 

[MichaelMouse]

You could always make an innie versus an outie for chucking, then sand things up prior to finishing the inside turning. My preferred. After all, what does the bottom of a salad bowl really look like? Bunch of spilled lettuce.

Other nice things about the innie are the natural "ring" to sit on, with no high middle. You can take an extra 3/8 depth on most bowls, and the one I had been taking for granted until I read others' complaints, optimum chuck sizing after drying. Since I rarely use tenons, It never occured to me that they might not make jaw size when re-trued after drying. With the innie you have to remove wood which has entered your circle, not take away to make a smaller circle. Gets you in the optimum size range both green and dry. For green wood you might want to put a piece of cloth over the jaws to keep them from transferring corrosion marks to the interior of the mortise.

I've got one of those Menards buffing kits myself, though I bought one of the super-duper Beall buffs to try it out. Seems to this eye that the grit does the job, versus the cloth, so I've never bought another fancy buff nor fancy buffing compound. If you're going to buff the wood rather than the finish, might want to go to the plain brown bag instead. It will heat, harden, and abrade to a smooth surface. What it won't do is round the edges of the wood pores, so you'll still have more snap to your visual surface from the diffraction sharp edges give.

I'll grab some shots of the piece I oiled yesterday and add them a bit later.

Just linseed, shine coat composition to be determined.

 

[Joe Greiner]

Despite the terminology, "finishing" doesn't have to be the final element of work, done all at once. You can turn the blank between centers, forming the outside and a tenon; "finish" the outside now if you like, or delay to the next step. Reverse mount using the tenon, hollow the inside, and "finish" the inside; plus the outside if delayed until now. Reverse again, using jam chuck, Cole jaws, Longworth chuck, plywood on the faceplate with tape securing it, vacuum chuck, or whatever; turn down the tenon to form the outside bottom, leaving a tiny pimple if done with the jam chuck to be carved off with a knife or hand chisel; "finish" the outside bottom if you must.

Stepwise "finishing" on the lathe is particularly recommended for goblets, whose stems can't withstand the rigors of "finishing" the bowl: "finish" the outside and inside of the bowl before seriously turning the stem. Blend the transitions as they develop.

Food for thought.

Joe