Tuesday, February 19, 2008
Glitch
I have suffered a modem meltdown and will soon be back online with new posts. Thanks for checking in and understanding the delay in email responses as well! Boy, if I could just carve the thing until it works!
Sunday, February 10, 2008
Potholes
My friend Rich came by the shop the other day and gave me grief for making the jointing in my last post look too easy (I think it was unrolling the shaving!). And he's absolutely right. One of the things that has always frustrated me about woodworking instruction in video and magazine form is that it is limited (for obvious reasons) to showing the correct way to do a task with a lot of basic assumptions taken for granted. It's like a road map that is showing you the correct route, but fails to mention that the bridge is out, the road changes to dirt sometimes and the journey is longer than you think!
I must admit, jointing an edge for gluing took me years to master. But it didn't have to. After much trial and error I came to realize that there are just a few major potholes along the way to avoid, and a couple of essentials for success. Once these are addressed, I can hand the task over to a novice and get great results.
The first major obstacle is of course sharpening the tool properly. In this case, it doesn't just mean getting a sharp edge, but a straight one as well. This can challenge even the most experienced sharpener. The photo above shows a plane iron and a chisel. Of course the plane iron is the tool for the job, but it is a terrible way to learn to sharpen. People trying to sharpen plane irons first are in for a nasty experience (hence all those jigs out there!). The bevel is too thin to easily balance on the stone while moving. Trying to develop the sensitivity and technique with this tool is just too much. So opting for the chisel, with it's much thicker bevel and narrower width is just the tonic. Master the chisel, and the plane iron will follow.
Below is a photo of a sharpening stone. You can see the black areas left behind after a few strokes on the drywall sanding screen. I have read about people using cinderblocks to flatten their stones, but this scares me to death! I find that the drywall screen is the perfect size and the piece of plate glass is easy enough to find.
Of course, the dark areas are the low spots and I keep rubbing the stone until it is one clean color like the image below.
So I've already done two of the most important parts of jointing and I haven't even gone near the wood. By choosing to practice with an thicker tool on a dead flat stone, I've laid the groundwork for success. I am working on a short video to show the proper strokes and grinding technique.
I must admit, jointing an edge for gluing took me years to master. But it didn't have to. After much trial and error I came to realize that there are just a few major potholes along the way to avoid, and a couple of essentials for success. Once these are addressed, I can hand the task over to a novice and get great results.
The first major obstacle is of course sharpening the tool properly. In this case, it doesn't just mean getting a sharp edge, but a straight one as well. This can challenge even the most experienced sharpener. The photo above shows a plane iron and a chisel. Of course the plane iron is the tool for the job, but it is a terrible way to learn to sharpen. People trying to sharpen plane irons first are in for a nasty experience (hence all those jigs out there!). The bevel is too thin to easily balance on the stone while moving. Trying to develop the sensitivity and technique with this tool is just too much. So opting for the chisel, with it's much thicker bevel and narrower width is just the tonic. Master the chisel, and the plane iron will follow.
Below is a photo of a sharpening stone. You can see the black areas left behind after a few strokes on the drywall sanding screen. I have read about people using cinderblocks to flatten their stones, but this scares me to death! I find that the drywall screen is the perfect size and the piece of plate glass is easy enough to find.
Of course, the dark areas are the low spots and I keep rubbing the stone until it is one clean color like the image below.
So I've already done two of the most important parts of jointing and I haven't even gone near the wood. By choosing to practice with an thicker tool on a dead flat stone, I've laid the groundwork for success. I am working on a short video to show the proper strokes and grinding technique.
Tuesday, February 5, 2008
Jointing for Seats
In an earlier post, I describe the technique that I use for aligning the grain when jointing for a seat blank. Of course, it's nice to avoid having to use anything but a single plank, but in this day of increasing scarcity, making invisible, solid joints is a good skill to have. Here is the way that I orient the grain so that the grain looks fluid on the carved surface.
Most of the difficulty in getting a perfect joint is going to be eliminated at the sharpening station (you're not suprised, are you?!). After much trial and error, I learned that the key to easy and true jointing is a dead flat plane iron. I carefully flatten my stones, which is the key to getting a flat edge, on drywall sanding screen and plate glass. Then I grind the edge carefully until I can hold a flat tool against it and see no light pass through, as show below (there is a window directly behind the blade).
Then I carefully hone the edge. As you can see below, the mirror finish should give an undistorted reflection right up to the edge. We haven't gone anywhere near the wood, and already the important part is over!
I've made a video of the technique that I use. The problem with most jointing, like honing, is the tendency to create a convex shape. With a plane iron, we use a hollow grind to give stability and to fight this natural tendency. I use the same principle for jointing the edge of a board. By creating a very slight hollow in the middle of the board, the plane will ride on the high spots and only cut on either end. When the plane takes a full length shaving of even thickness, I know to stop, and the board is truly flat.
It is of course vital that the pressure on the plane is always over the board. If you put pressure on the part that overhangs in the beginning or end of the stroke, you can round the edge.
If the process doesn't work the first time, simply take a couple of shavings from the middle of the board and try again. Honestly, without a properly flattened plane iron, I cannot do this, so if you have trouble, look to the blade. Below is the unclamped joint. It should sit snugly with nothing but gravity. Good luck!
Most of the difficulty in getting a perfect joint is going to be eliminated at the sharpening station (you're not suprised, are you?!). After much trial and error, I learned that the key to easy and true jointing is a dead flat plane iron. I carefully flatten my stones, which is the key to getting a flat edge, on drywall sanding screen and plate glass. Then I grind the edge carefully until I can hold a flat tool against it and see no light pass through, as show below (there is a window directly behind the blade).
Then I carefully hone the edge. As you can see below, the mirror finish should give an undistorted reflection right up to the edge. We haven't gone anywhere near the wood, and already the important part is over!
I've made a video of the technique that I use. The problem with most jointing, like honing, is the tendency to create a convex shape. With a plane iron, we use a hollow grind to give stability and to fight this natural tendency. I use the same principle for jointing the edge of a board. By creating a very slight hollow in the middle of the board, the plane will ride on the high spots and only cut on either end. When the plane takes a full length shaving of even thickness, I know to stop, and the board is truly flat.
It is of course vital that the pressure on the plane is always over the board. If you put pressure on the part that overhangs in the beginning or end of the stroke, you can round the edge.
If the process doesn't work the first time, simply take a couple of shavings from the middle of the board and try again. Honestly, without a properly flattened plane iron, I cannot do this, so if you have trouble, look to the blade. Below is the unclamped joint. It should sit snugly with nothing but gravity. Good luck!
A Problem Tool
I received a question about the angle of my inshave handles recently. I thought that the difficulty that the inquirer had was a result of technique, but after some recent discussions, I realize that I was incorrect. Apparently, the inshave being sold by Highland is different than the one that I use. It seems that the handles of the Highland tool when measured off of the bench (as seen in the photo of my correct inshave) are too upright for seat carving. Simply put, they get in the way.
My handles are at about 120 degrees off the bench. I spoke with Doug Roper in California today and he said that he spoke with Highland about the problem and that they agreed to take the tool back. I hope that the problem hasn't affected too many folks, and I am going to look into finding a supplier with the correct tool geometry.
My handles are at about 120 degrees off the bench. I spoke with Doug Roper in California today and he said that he spoke with Highland about the problem and that they agreed to take the tool back. I hope that the problem hasn't affected too many folks, and I am going to look into finding a supplier with the correct tool geometry.
A Somber Return
Here is the Chair Notes cover girl on her whirlwind Florida vacation. We managed to sneak off for a few days and soak up some warmth.
And this is what we came back to! Oh, well, at least syrup season will be coming soon!
I've been using a feature of the blog lately that I want to emphasize for those who haven't noticed. There is a key word search feature that allows you to look for topics of interest. I have enough posts now that I can't even remember where everything is, so the search function has become a favorite when I am in need of previously posted info. Try it out!
And this is what we came back to! Oh, well, at least syrup season will be coming soon!
I've been using a feature of the blog lately that I want to emphasize for those who haven't noticed. There is a key word search feature that allows you to look for topics of interest. I have enough posts now that I can't even remember where everything is, so the search function has become a favorite when I am in need of previously posted info. Try it out!