When I posted "A burly gloat" on some box elder burl I bought from Northwoods, I noted that Les threw in a piece of spalted BLM burl. Steve Schlumpf really liked the BLM piece, as did I. I decided it would be the subject of my next turning.
Jon Prouty asked if I would post some pics of the work in progress, so, here goes. This will take a few days, as my shop time has been a little spotty. It will also take some space and several posts.
David Reed observed that this piece might be a little soft - and, it was. It didn't feel that way when I first got the wood, and it passed my "fingernail" test for punkiness. When I got into it, there was a fair amount of "crumbly" wood. But, we will make the best of it!
This is the chunk of BLM - about 6" x 8" x 3" thick. I band sawed it to a 6" round.
1 SPALTED BLM BURL.JPG
This is the sketch of the turning.
2 SKETCH.JPG
I am quite sure my methods lack a lot, but just some general comments about how I go about this. I keep a sketch pad by my easy chair, and when I am feeling creative, I will make several quick sketches and I leave them there to be pondered over the next few days. Some just don't work for me, and others do. If they "make the grade" then I will convert them to 1/4" grid paper. I wish I could use Illustrator like David D. does - would be so neat. He has provided me some other technical ideas that include a digital "sketch pad" that will save a file in format compatible with Illustrator and other programs. That is on the "someday" list!
I try to do something different with each turning - a little different form, or a different style finial, etc. Generally, I do not have in mind the wood to use for it until after the sketch is done. However, I did this sketch specifically for this piece of wood.
The rule of thirds is used as much as possible, and in this case, the thinnest part of the pedestal is at the 2/3 point. Likewise, the widest diameter of the form is at the 2/3 point.
Usually, a pedestal just doesn't look right being the same height as the form, but with this shape, it seemed to look OK. You all may differ on that, and that is OK. I have found that folks really view these things differently. Seems the shape of the form can really play games with the rule of thirds - requiring one to account for the shifted mass of the form.
I also try to make sure the protruding elements of the finial touch a fair curve coming off the shoulder of the piece, and that is the faint curved line drawn on the top. The thought on this one was to have a black pedestal/finial to pick up on the spalt lines.
The first step, in order to preserve as much thickness as possible, was to glue on a waste block. I keep on my bench several 2+" disks of poplar, maple, or whatever scrap wood I have around. I marked the center of the BLM, and with a compass, marked a circle a little larger than the waste block. I marked the center of the waste block, and with Titebond, I clamped the block on the BLM and left it overnight. By the time I decided to do this thread, I had already roughed out the form.
3 WASTE TENON.JPG
When I am getting the shape of the form, I have the sketch lying on my lathe for reference. I also use a set of calipers for various dimensions on the piece in critical locations or transition points.
4 SKETCH AND FORMING.JPG
Here the piece is generally shaped - leaving plenty of "meat" at the base for hollowing. I already know the final shape and dimensions, so when I hollow, I will hollow to the "imaginary" final form.
5 GENERAL SHAPING.JPG
Before hollowing, I use a 3/8" electrician's bit to drill out the center to final depth. This gets rid of the center nub.
6 DRILLING.JPG
I use a Monster hollowing rig, and I didn't document that process. It is rather mundane - kind of like watching grass grow!
This is the hollowed form - sanded to 400 and with several coats of lacquer thinned with acetone. I had a very difficult time getting a clean cut for the finial shelf. This is where the punkiness really created issues. A lot of the inside of this form came out in granules the size of instant coffee, and the area around the opening was really soft and wanted to break out on me.
7 HOLLOWED 1.JPG
And, this is the hollowed form from the side.
8 HOLLOWED 2.JPG
More to come.....