Tuesday, October 30, 2007

Steamer Revisited

Thanks to everyone that took the time to comment on my post about the red oak log. I knew that it was bound to start a conversation. All of us have different experience and different wood, and being cheap as I am, I will continue to monkey around with the red oak that is next to my shop until I can be certain that it won't bend!

Someone mentioned my steambox in one of the responses and it got me to thinking. My steamer has served me well for a long time with almost no breaks, but there has always been one thing that bothered me and I figured that now would be a good time to deal with it. The Lee Valley steampot that I use cranks out a huge volume of steam, the only problem is that it runs out of water too quickly. Having to refill the steamer during use has always been a pain as well as introducing an unnecessary variable.

I have been thinking of hooking up a reserve tank that would automatically fill as the pot got low. I believe that I recall reading that someone somewhere had done this. Now to figure how to do it.



I have an automatic dog waterer that works like an office style water cooler. When the level in the bowl goes down, air can enter the bottom of the upside down bottle and release just enough water to block further air from entering the bottle which stops water from running out. I figured that there must be a way to use this principle with the steam pot.
After some tinkering, I came up with this simple setup. The only difference between this and the dog waterer is the heating element. It works great. The steamer can easily run for an hour (previously it seemed to only run for about 30 minutes).
One of the unexpected benefits of the set up is that the air that enters the reserve jar is hot and preheats the water so that as it drops into the steampot, the temperature doesn't drop. It also seems to have a percolation type exchange, I don't understand all the physics, but I do know that the jar gets damn hot!

Another benefit of the setup is that when the pot goes below a certain level, almost all of the water drops out of the jar. This acts as a sort of a timer, it takes about 45 minutes for the reserve jar to empty (the pot is still going strong) which is perfect for my usual steaming.



In the name of testing, I took a white oak arm that I mismeasured (should've finished my coffee first) and put it in the steamer. It bent beautifully, so beautifully that I dediced to keep going. It took this bend without giving up a single fiber.
Now that I have my steamer supercharged, I plan to give that red oak another chance. I still don't think that I'll be buying more of it, but I hate to waste a good log.

Friday, October 26, 2007

CFA Workshop

I will be hosting a free chairmaking workshop on Saturday November 3rd, sponsored by The Catskill Forest Association. You can contact them to register or for more info at http://www.catskillforest.org/Events.html. I will demonstrate splitting, shaving, sharpening, bending, seat carving and turning, as well as general chair info. So get going to the beautiful southern Catskills in New York, see you there.

Tuesday, October 23, 2007

The Last Red Oak



I went to my sawyer for a log last Saturday. I was taken by this view as I came over the hill in an area known as the Beechwoods.
Much to my dismay, my sawyer had just sawn the last of his white oak logs and only had red oak to offer me. Knowing that I had a student coming Monday gave me little choice. So I chose a relatively small red oak, given that more white oaks would soon be available.

I don't normally use red oak. It has a texture and lightness that I don't care for, preferring the density of white oak. Also, the only dramatic breaks in bending and spindles that I've personally seen have been in red oak. It's a shame really, because large, clear red oaks are always easy to find in my region.
But, beggars ...



Here is Bruce Bidwell cracking the log. Everything went smoothly, although it was a little more hornery than usual. I realize while we were splitting out our pieces that there is a great difference in the way that this red oak splits. It was much more difficult to control the splits than I am used to with white oak, it didn't have the fibrous quality.
Once we got the wood to the shave horse, I also found the red oak to be less fun to shave. Normally, with white oak, my drawknife slips between the fibers and follows them easily. With the red oak, I found that I had to pay much more attention to the visual clues to confirm whether I was with the fiber line. But we shaved it, and Bruce has a fine set of spindles to show for it.

Bending wood with a student is always a fun time for me. After all the hard work that they put in, learning to split and shave along the fibers, they get to see the results as the wood becomes fluid.
I think you know where this is going.
The trouble started immediately. As I pulled the piece, expecting it to flow around the top of the curve, I heard the cracking. A cross fiber shearing, not the subtly lifting of errant fibers, but a full on break.
There was nothing to be done.

Every log is different, and I've had some fine luck with bending red oak. Perhaps it's too easy to accept when a prejudice seems confirmed, and I'm sure I won't be able to resist another try (steamer problems?), but for now, I won't be buying any more red oak.

Luckily, I remembered that I had sunk a bolt of white oak in my pond last summer for just such emergencies. And tomorrow we start again.

Thursday, October 18, 2007

Drawing

I like to draw my new designs before making any sort of a mock up or prototype. Below is a drawing of a chair that I designed in 2001. I start with a basic idea for the design and then draw a stick chair version of all of the simple parts, such as the leg angles etc... By projecting the front, side and top view, I can plot points and see exactly what the results will yield.



I normally start with the shape and size of the seat that I am interested in and then down to the legs. By using the tables devised by Dave Sawyer in Drew Langsners book, I can easily get the resultant and sighting angles for my pattern.

Learning to do this kind of projected drawing is not as tough as it may look. You start by arranging the page (graph paper is essential) so that the top view will fit directly above the front view and so that the side view will fit directly to the right of the front view. The key is the 45 degree line that acts to link the top and the side view. For example, draw a vertical line from the front of the seat in the side view all the way to the diagonal line. Then draw a hortizontal line from that point on the diagonal across to the top view. This will show where the front of the seat is when viewed from above.

Often, in designing, I switch back and forth from view to view as I arrive at what looks best. Obviously, the top view will be very important as you proceed to make a seat pattern, but I find that it is best arrived at by working the other views first.

After my stick chair drawing is complete, I'll often draw in some of the aesthetic details that will give the chair much of its character. This can inpire me even more to want see the chair in wood. While drawing is a good start and a great way to save a lot of fiddling around, more often than not, the actual chair calls for more than a few refinements.

To learn how to do this kind of projection, I suggest starting with a simple object, such as a brick, and work your way toward more the complex. Once you get your head into it, you'll start thinking in 3 views!

Tuesday, October 16, 2007

Home Again



Here is a picture of Chairnotes covergirl Sue Scott (left) with our friends Clint and Molly Paugh during our trip this weekend to Kansas City. They showed us a wonderful time as well as the best BBQ I've ever had (LC's).

While we were waiting for a table at Sunday brunch, we ambled around a flea market where we came across a man selling old wooden patterns from New Orleans. Patternmaking has always fascinated me and I think of it as one of the highest forms of woodworking. These patterns (shapes) are the beginning in the old casting process. So whatever shape you needed to make an engine part etc... was first created in wood by a patternmaker. The piece below is of a gear that, as far as I can tell, changed the direction of a linear drive. It is also interesting because it only needed to turn a segment of the circle. I enjoy imagining the machine that it fit in.




So often, when I look at the discussions surrounding handtools on the internet forums, they focus on handplanes and the flattening or surfacing of wood. There is a limit to my interest in this, although, I too was fascinated by the notion that a blade can actually shear the wood so cleanly. I would love to see the conversation take a turn towards the type of work involved in creating patterns. The awareness of the fibers, the fluid use of handtools and the mastery of shape is something that I aspire to. Now I just have to decide whether to hang my new pattern in the shop or in the house!

Friday, October 12, 2007

White Knuckling

I spend a lot of time with students trying to get them to stop with the "death grip". Most of the time, handtools require a light touch to feel the vibration of the cutting edge as it slices and holding too tightly simply deadens sensation and causes premature fatigue.

One exception to this is during sharpening. I am on my usual crusade to relegate sharpening jigs to horse and buggy status. The image below is an example of the pressure that I exert directly over the bevel of the tool as I pull it across the stone. It isn't necessary to be able to do this without the assistance of the other hand on the tool, but it correctly describes the distribution of the pressure. The hand on the handle should supply just enough help to make up for the weight of the handle. Try it.



I remember watching experienced sharpeners use all sorts of seemingly carefree hand positions and motions during sharpening. Good for them, but it only served to cloud the issue for me. For those weaning themselves off of the jigs, I suggest starting with your thickest blade with a complete hollow grind. This will give the most feedback as to when it is truly cubbed against the stone (your stone is dead flat, right?!). Once you feel this solidly, pull the tool back across the stone. At the end of the stroke, lighten up on the pressure and the tool will naturally lay back on the heel of the bevel. Pick the tool up and put it back on the stone furthest from you, repeat. Yes, I am advocating just pulling, with the tool held slightly askew for better stability. By just pulling you can better focus on keeping the correct pressure and you are moving closer to your own center of gravity. Also, the tendency of the tool will be to lay back harmlessly on the heel of the bevel versus the disastrous tipping onto the toe, which can dig into the stone and easily send you back to the grinder.

It is more important that the tool is in the correct position than how many strokes you take. Remember, one lousy stroke will misshape the point and undo all of your good strokes. Water stones etc... cut fast enough that with a hollow grind, it won't take but a few strokes done this way to be ready for the next stone. So bring your elbows in, and push the bevel into the stone until your knuckle turns white, if it doesn't feel awkward at first, your probably not doing it right!

Thursday, October 11, 2007

The Cobblers Children

The old saying "The cobblers children have no shoes" has fit the bill as far as my most recent chairs go. I have not had the time to make myself one of the cherry chairs with the bent spindles that I have been making for clients. People like to tease me about the amount of chairs that I must have, and it's true, I am tripping over them constantly. The only problem is that the chairs that I own are all of the early ones and I generally watch as my best work goes out the door. Well, finally my shifting of my business plan has afforded me the time to make myself a chair. I have gone from taking orders to taking names on a list that I can call when the time affords. This wonderful piece of business advice came from my friend Curtis (hey, when are you going to start taking your own advice?!)




I decided to use the last of my hickory log to create a dramatic contrast with the spindles. Hickory is one of my favorite woods for spindles. I hardy ever use it for bends, even though it often bends beautifully, because it tends to shrink dramatically and therefore check a lot. In most chairs, I find hickory too strong, leaving the back inflexible. I tend to use it in combbacks where the spindles offer the only support for the upper back or when it's strength is of benefit.
I wish that all spindles called for hickory. Once you get used to the lack of obvious clues (such as the rays in white oak), shaving with the fiber line is easy and no wood has the creamy texture of hickory. My sawyer calls me when he gets a great hickory, and luckily, fall is here and it's time to get a new one (they rot in summer!).
Now my only challenge is to hold onto my new chair, in the face of the mortgage, the insurance, and oh yeah, christmas is coming!

Wednesday, October 10, 2007

Parting Tool Grinding

Honestly, one of my favorite activities is trying out new parting tool grinds. (Maybe I need to get out more!) There are a whole slew of them and my favorite tends to be the one that I'm using at the moment. The most important factor in parting tool grinding is of course frequency. I grind all the time. At this point I don't bother to hone my parting tool, I simply grind it and knock the burr off by dropping the tip into a block of soft wood and then get back to work.



Above is a photo of my technique for grinding the lower facet of the bevel. By grinding it on its side, the facet will curve (slightly) from side to side. Below is the grind that I use on the top facet. It imparts the curve from the toe to the heel of the bevel. By have the facets curve in different directions and meet at the tip, a slight spur is formed at the corners. The spurs help ensure a clean cut.



It is crucial that the grinding be done square to the axis of the tool. The diamond shape can make this tough to see. I like to look at the relationship of the bevel to the square edges at the top and bottom of the tool. Below is a picture of the (relatively) square grind.


alt=""id="BLOGGER_PHOTO_ID_5119823658096405218" />

To function properly, the two bevels should meet and form a square line across the tip of the tool that seems to connect the widest part of the diamond. It is critical that the actual leading edge be square to the axis so that readings of the dimension of the workpiece not be thrown off by an angled surface. I don't have any absolutes as to the angle of the grind, I tend to freehand the top bevel on the wheel, and then get back to work. The lower bevel only gets ground when absolutely necessary because it takes a time consuming set up. Improving the performance of this tool may seem to be a waste of time, but I have come to see a smooth cut into the diameter of a fresh turning blank as gratifying as the final sweep with the skew.


Tuesday, October 9, 2007

The Lowly Parting Tool

I am going to focus a couple of posts on the care and proper use of the much maligned parting tool. Here is a turning tool that is most often abused, misused and treated as an necessity rather than a choice. The parting tool sets the diameters for all of the details in spindle turning but gets none of the glory of skewing a perfect surface or cutting a flowing cove. I have seen many turners grit their teeth while jamming a dull parting tool straight into the spinning piece, the vibration, noise , and yes, the smoke! confirms the lowly status of this tool.

I'll talk about the sharpening process later, now I'd like to pretend the tool is in top notch condition and focus on technique. Below, you see a 1/8" diamond parting tool (I am thrilled to find that Sorby still offers these). The diamond shape helps to ensure that the tool won't bind in the groove that it is cutting. The widest point of the tool is 1/8" which helps reduce vibration. As I've noted in earlier posts, vibration begets vibration, and by using the parting tool correctly, this initial rumbling can be avoided.




The key to cutting with the parting tool is to use a shearing cut as opposed to a scraping cut. This is best achieved by rubbing the bevel of the tool against the (fast) spinning work piece and slowly raising the back of the handle until the cutting edge makes contact. At this point a shaving will shoot along the top of the tool. Here is where many go wrong. Don't just continue lifting the handle. This will transition into a scraping cut as the diameter gets smaller. Instead, feed the tool into the cut by pushing forward. The result of this may be that the cutting edge lifts out of the wood and the tool will once again be rubbing on the bevel.
This is fine.
Once again raise the rear handle and engage the cutting edge. When done correctly, the rate of feeding the tool forward and the rate of raising the rear of the handle will keep the tool cutting high enough on the round to maintain a continuous shearing cut. Above is the correct position to hold the tool when cutting a large diameter. Below is the correct position when cutting a small diameter. Notice the different angle of the parting tool, but the relationship to the diameter is the same as far as the cutting edge is concerned. The skill is maintaining that correct angle as you cut from one diameter to the other.
It is definitely better to stop cutting by feeding the tool forward too much than to let the tool scrape. To make the whole process a bit tougher, wiggling a bit side to side as you cut will also help the kerf stay wide enough to reduce vibration.




Below is the scraping position, easy yes, but it will make it hard to love this tool. I have come to enjoy my parting tool now that I shear cut, grind often and give it that funny wiggle. Grinding is next.