Wednesday, November 16, 2016

Wood Turning FAIL and recovery (or, Turned Segmented Bowl v1.0)

The turned wooden bowl I posted last week was the first one I finished, but not the first one I started. I had originally started a much more elaborate design for my first piece, but I got impatient waiting for it to glue up, so I started turning #2 first. As it turned out, #1 was a little too ambitious, and suffered from a lack of planning.

I literally just started cutting up pieces into strips and gluing them together. I knew it would be made of layers of rings, and those rings would probably have something like 8 segments each, but that's about all the planning I had put into it. My first ring I made turned out way larger than I thought it would be and had to be cut down. Then I just started slapping things together.
Some of the rings were octagonal and some were square. Some were cheap reclaimed pine, and others were reclaimed oak. The sizes of the rings were haphazard, and at one point I had to make an extra ring as a transition because the sizes were too far apart. I planed to let the sizes of the rings  dictate the shape of the bowl.
I figured out during glue up, that I had not planned on how to clamp an octagonal ring of wooden segments. I made due with electrical tape stretched around the rim.

Then, lots of sanding to even up the faces and hide the crimes. I had to add some super glue to some of the joints because I had gaps. I guess my chop saw is not calibrated very precisely, because the angles didn't quite meet up as the should have.

Then the rings were glued together into a cone type shape of sorts. It was around this time that I got impatient to get my bowl turning on, so I started turning the simpler blank (#2) that I started gluing up while I was struggling with the rings.
After attaching to a glue block for mounting onto the lathe, the turning began. Right away things were off to a rocky start, with the whole rig being unbalanced as hell. I worked quickly to turn the protruding corners off the rings just to get the table to stop shaking.
 The rings were far too disproportional from one another. The transitions from one ring to the next were very hard to smooth out, and I had many instances of tare out, some very violent ones that sent large chunks of wood flying into me. The edges of the rings wanted to catch on my chisels, and I came much closer to being injured on this project than on any lathe project previous.
Just as I was getting the transitions under control, I had a blow out. I stopped the lathe to check my progress, as I often do, and noticed that one of the segments had been cut all the way through in spots. FAIL. I unmounted the piece and tossed it in the scrap bin.

But wait! I think we've established what a cheap bastard I am, and how I can't let anything remotely usable go to waste. So I rescued the failed piece from the scrap bin and decided that since only the top ring was ruined, I could probably cut off that ring and replace it with a new top ring.  So I re-mounted the piece to the face plate, and started parting off the ruined top ring.
Then, once the top ring was off, I decided that I was too lazy and impatient to make a new top ring. I would just try to turn what was left into a bowl. Even without the top ring, it was almost as tall as the bowl I just finished yesterday.
The turning was problematic, I'll tell you that much. I had a lot of bad catches- a lot of gouging and chip out. And the transitions from ring to ring were tough to smooth out. This bowl would have benefited from some better planning, that's for sure. And sharper tools (I'm bad at sharpening, and sharp tools are the key to good wood turning). And I burned my fingers pretty good being impatient with the sand paper. You see, I'm to lazy and impatient to change the pulleys to adjust the speed of the lathe, so I sand at the same speed I turn, which is much too fast. This whole project had me impatient and frustrated, and I kind of rushed through it. Maybe that's why it encountered so many problems.
Anyway, the final product turned out to be acceptable- nice even. I think my next bowl will be a little less ambitious and better planned out. I obviously need more practice with bowl turning before I start doing anything fancy.

Wednesday, November 9, 2016

Turned Segmented Bowl v2.0

On the heels of my return to the lathe, following my successful attempt at creating turned wooden pendulums, I thought I would try my hand at turning something other than a spindle shape. The easiest thing to start with was a bowl.

I like using reclaimed wood for projects. Probably because I'm a cheap bastard who doesn't like paying a lot for supplies. But also because I can't stand to see anything useful get thrown out and wasted. This bowl was a test project, so I was definitely not going to use good wood for it. I found this wood in the garbage. The thick lighter pieces were from a reclaimed cheap bed frame (probably pine or fir), and the thinner darker strip in the middle was straight out of my scrap bin.

I sanded the faces as flat as I could get them, without a planer or jointer or drum sander, so that they would glue up without any gaps. Then I sandwiched them together with wood glue and clamped them for a couple of hours.

Using another piece of scrap wood, I made a sacrificial glue block and attached it to a face plate, which will screw onto the head stock of my lathe. 

Then I trimmed the corners off of the blank with the band saw, just to make getting it round a little easier. 

I attached the glue block with some super glue, which will be challenging but not impossible to remove from the base once it is finished. 

Then, start rounding it out and shaping the exterior.

 The center layer of wood was not a solid block, but a square ring of smaller pieces, so once I broke through the top layer of the block, there was a void beneath it.

 After shaping, came sanding. Sanding always takes longer than I think it will. Maybe because my turning technique is weak (and my tools are not as sharp as the should be). I start with 80 grit sand paper and then go through 120, 320, 500 and 1000. I can still do a little shaping with everything through 500. The 1000 grit is basically just polishing.

After sanding comes finish. I like to apply my finish right on the lathe whenever possible. For this, I used a friction polish that some call O.B.'s Shine Juice. It is 1 part boiled linseed oil, 1 part shellac, and 1 part denatured alcohol.  It is applied with a paper towel in thin coats, with the lath turning , and buffed immediately between coats with a dry paper towel. The heat from the buffing dries the finish in seconds and it is ready for another coat. I usually apply 5 or 6 coats.

 The last step was to part the bowl from the glue block. I started by separating it near the joint with a parting tool, then when the connection was small and weak, I was able to pop the rest of the superglue loose by hand. Then I sanded the bottom of the bowl smooth and applied a couple coats of Shine Juice (off the lathe) and buffed with a paper towel.

 The picture below makes the bowl look more yellow than it really is. I think the blue rag messed with the camera's color balance. Although, the Shine Juice will impart a very slight yellow to the wood from the shellac and BLO.

This is a much more accurate depiction of the color.

 Wood turning is fun, but it does make a hell of a mess!