Saturday, March 25, 2006

Cutting large pieces of wood

I have had a couple of large pieces of wood outside the workshop for several months waiting for me to get them cut up and roughed out into bowl blanks. I made a start on them a few days ago, and I thought I would share some pictures with you.

This first piece is a crotch of yellow birch and I want to take a slab out of the middle to remove the pith, leaving two big bowl blanks on either side. In this first photograph you can see how I have marked cut lines all the way around the log. My chainsaw is not large enough to cut all the way through in one go, so it will need to be attacked from all sides. Careful marking and cutting is important so that the saw cuts are all in the same plane. So here I have the log on a flat surface and have a used a piece of card cut to the desired width to ensure accurate marking out.

Notice that I have trimmed a little bark off both sides. This makes it easy to mark the lines, and also makes it easy to stand the log on its side for cutting as you can see in the next picture. Here
I start by carefully cutting a shallow groove all the way around the marked lines. This not only makes them more visible, but will also make it easier to control the saw when the main cutting starts.

The hardest part of cutting these grooves are the cuts across the endgrain. Chainsaws aren't designed to cut endgrain, and the end of the bar tends to wander sideways if it is not kept in a groove. So I cut the grooves along the sidegrain first, then used that to anchor the bar while I let the power unit down to extend the cut across the endgrain. Working this way makes the line difficult to see, so I stopped frequently to check that I was following the line accurately.

Once the grooves are cut all the way around, work can begin making deeper cuts into the wood. Start at the corners, making diagonal cuts and ensure that the bar stays in the grooves on both faces. Work all the way around cutting deeper and deeper. Take care when the nose of the bar gets into the wood; this is the danger area for getting a kickback.

I worked on both cuts at the same time to keep the piece balanced and stable for as long as possible. Once one side was removed, the remainder had to be balanced against a bench leg to keep it upright. Here are the three pieces finally seperated.

Even with all the care I took, some of the cuts wandered off a little bit. Even so, this was much more accurate than if I had tried to eyeball it.

Here is one of the pieces off the side, trimmed up and ready to be turned. Spending a few minutes with the chainsaw can save a lot of turning time with these large unbalanced pieces of wood.

Finally here is the central slab after it has been cut on the bandsaw. This piece had the piths running through it and this needed to be removed. The round piece is destined to become a small bowl and was located to avoid the pith. You can see some of the nice crotch figure in that piece. The two large pieces down the sides could be used for either small bowls or for weedpots. They will be dried first, so I don't have to make a decision yet as to what they will be used for. the two smaller pieces have remnants of pith in them, so they are likely to split. I haven't decided yet what to do with them, but they will probably be cut up even smaller and prepared for bottle stoppers or inlays.

If you take on a project like this, do take care with the chainsaw. If you are unsure if what you plan to do is safe, get some help.

Monday, March 20, 2006

Turned Wood - Small Treasures 2006

The del Mano Gallery is currently showing its annual exhibit, Turned Wood - Small Treasures. With work from over 60 artists, all of whom are showing technically and aesthetically brilliant work, it would take too long for me to look at them all, so I have chosen just three which caught my eye.

The most original in my opinion is Glenn Krueg's series Asian Temples. These are beautifully executed assemblages, rich in textures, forms and colours. As well as the Asian theme, perhaps they are also temples to the art and craft of woodturning?

Segmented work seldom appeals to me, but William Smith's Spiral Galaxy caught my eye. It makes bold use of colour while its minimalist pattern is very pleasing to the eye. I found no pleasure in Kaleidoscope II or Purple Spiral, but I did find the Emergence series interesting. At first sight I thought that William had used a novel and technically complicated method of assembling just a few pieces of wood. Closer examination shows that it is in fact made from multiple blocks, but the glue lines between similar colour blocks have been disguised by the surface texturing, giving a very pleasing overall effect. There is very little overlap between the blocks and William must have more confidence in the strength of a glued joint than I do.

Finally I want to point out Molly Winton's pyrographed vessels. I was particularly drawn to The Hunt and others on that theme. The beautifully rich colours of the wood contrast so well with the dark pyrographed areas and form the wonderful backdrop for the sketches. The turnings themself have a simple elegance that will stand the test of time.

There are many other marvellous things to see in Turned Wood - Small Treasures so do please go and take a browse. I'd love to know what you liked, so please leave a comment or a trackback from your own blog.

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Tuesday, March 07, 2006

Spare wheels for the Beall buffing system

When you order spare wheels for the Beall Buffing System, make sure you order the right ones. I just discovered that they sell two different types; one for the standard motor-mounted buffer, and one for the three-on-a-mandrel system.

The difference is in the mounting hole. The wheels for the mandrel system have a much larger hole. So when I realised my mistake and figured out what was going on, I decided to turn a spacer rather than go to the trouble of returning the wheel. Here you can see the new wooden spacer mounted on the bolt.

The spacer is turned so that it is a snug fit in the hole. It's length is a little trickier. It needs to be long enough to support the wheel, but not so long that it prevents the nut tightening sufficiently to grip the wheel. Hopefully though, you will never need to do this!

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