Thursday, April 29, 2010

Seeing the Light

I can't be the only one out there to discover, too late, a little spot of glue that I missed during cleanup. When painting a chair it shows up as a spot where the paint won't stick but even worse, when working cherry it shows up as a light spot months later as the rest of the piece darkens.

I was reading the book on hide glue that I got from Tools for Working Wood and the author mentions that the glue glows under a UV light. So I went on Amazon and got a UV flashlight, and there it is.


This is the chair that my current student is working on. We don't bother to clean the glue off of the top of the seat because it will be scraped later, so it provided a perfect test case.


Apparently, the best range of nanometer is 365 for detecting a large range of light waves that fluoresce, but the 385 nm light that I got for $12 works fine.
Next I spent a minute with some warm water cleaning the surface around the joint, and sure enough, no glow.


How cool is that!
I also wanted to mention that Greg Pennington has brought my posts on handling drawknives to a new level by bending the tangs to change his knife from a bevel down to a bevel up user. Check it out. Well done Greg.

I've been spending more time on hide glue and the chair joints lately, trying to better understand some things that have been passing for assumptions. I'll be posting more on the results as they come in.

Monday, April 26, 2010

Getting a Handle On It Part 3 etc...

This is the final entry about rehandling drawknives, but first, I'd like to show a few recent events here around the homestead. Before he left for Alabama, Seth turned some new mauls from my hickory log. I couldn't resist setting a new one amongst the mauls that I've been beating on for the last few years. I don't think of myself as nostalgic, but I can't bring myself to burn the old ones after their service.


Here is Bill Burslem with a chair that he made with me a few weeks back. Bill is a retired doctor who spends his time making stuff and volunteering in Ethiopia and the Gulf Coast. It's a pleasure to work with someone so accomplished and generous.


Below is our little goat Maggie who is very pregnant and has us on the edge of our seats. It's no exaggeration to say that I check on her every few hours (she's happy to see me at 3 a.m.).
She's quite a trooper carrying all that extra weight on her little frame, we think it might be twins!


Back to the drawknife. After the peening to remove the cap, the end of the tang is work hardened and would be difficult to repeen. So I anneal it with a torch (a gas stovetop would also work). Get the end cherry hot and let it cool slowly, certainly don't quench it, which would harden it.


Next is driving the handle on. If you've sized the holes right, you should be concerned about it splitting. I use a board with a hole in it to pound it into position.


Use the end cap to check if the tang is sticking out enough.


And finally peen over the softened end to hold the cap and handle in place.

Here is the finished handle. I replaced the other one and am happy to have this old tool back in service. All that's left is to peel the protective tape (it's there to protect me, not the blade!) and get back to work.


I've got lots of new stuff happening in the shop that I'm excited to share, from fluorescent glue to diamond paste, so check back soon.

Sunday, April 25, 2010

Getting a Handle On It Part 2


There are many different shapes of handles on drawknives and personal preference and comfort will dictate the shape for you. In remaking this tool, I decided to use the previous handles as a guide. If I'd chosen to make a different shape, there are only a few dimensions that I'd need to keep, the diameters at both ends and the length.


Above is the pattern I used. I wasn't fetishistic about getting it perfect, close works fine for me. One tricky part of the turning is the cap end. Below, you can see how the original was turned. Not only does the round cap "flow" with the rest of the handle, but it sits flush to the wood on a small shoulder.


I cut the blank to final length before starting, which allows me to check that the ferrule and cap fit correctly. Most important is that the ferrule is tight, otherwise as I drive the handle into position, it can split and send me back to the lathe!


If I didn't have a small drive center, I'd flip the piece in the lathe so that I could work the cap end safely.


Here's the finished handle. I oiled it on the lathe. My choice of the curly maple was based in it sitting next to the lathe, any hardwood will most likely do.


Drilling out the core might prove to be the greatest challenge, not because it's so tough to achieve (the lathe makes it easy and accurate) but because of you have to transform the shanks size and taper into a stepped hole. This part sent me back to the lathe a few times before I got it right. I suppose that having the hole too small is preferred. For one, it will be super tight and two, if it splits during assembly at least it's easy to remove to start over!


I use a Jacobs Chuck to drill the core. I found it easiest to start with the large end.


Once the large end is drilled, I flip the handle in the lathe and replace my normal cup center on the tail stock with this handle hollow center that Nick Cook made for me (perhaps another post coming soon). It can still be done with the regular center, but the large hole makes it a tad bit awkward.


Next I'll show how I knock the handle on the drawknife.

Thursday, April 22, 2010

Getting a Handle On It

Here's a topic that I've been aching to write about. In past posts, I've talked about the factors that, for me, make a drawknife worthy of buying. A lack of pitting, a straight blade, good steel and lastly solid handles. Well, finally, my collection of drawknives with loose handles has pushed me to address this handle issue, and I'm quite happy to have done it, because now I can offer a new life to those misfit drawknives that I used to pass by.


The first step in replacing drawknife handles, beside a big gulp for fear of never getting it right, is to split off the old one. By splitting off the handle, the ferrule, tang and end cap are left in pristine condition.


It is one of those "can't turn back" moments, but let's face it, the knife was just sitting around any way. The anatomy of the old tang is interesting. As I've found them, they are rectangular tapers that transition into a round shank.


Looking at the split handle gives a clue as to how to remake it. There is a stepped hole drilled through the center. But before turning the handle, the end cap and ferrule must be removed. To do this, I pushed the endcap, which is held on the shaft via the peened end, up on the shaft and pounded the end out so that the cap could slide off. Later, I'll show how to anneal the end so that the shaft can be peened again to hold the end cap in place.


Above is the end of the shank after being pounded out. Besides being a relatively simple and fun project, I am anticipating the moment where I am standing in front of a tool dealer after hearing the price of a drawknife when I can say "yeah, but the handles are loose."
Next is making the new handle.

Monday, April 12, 2010

Scorp Rehab

Curved tools can be baffling when it comes to sharpening. The normal hurdles of keeping the blade flat on the bevel while stoning give way to a whole new array of techniques.

I thought that my recently acquired inshave would be a good place to start down this winding road.


The basic rules and goal of sharpening still apply, two polished planes meeting along a single invisible edge. The trouble comes in shaping the surfaces to get them evenly polished.
Some inshaves have a knife edge with no distinct bevel. I'll be honest, I've got no idea how to maintain the polish and geometry of these tools. I prefer to have a bevel on the outer edge of the tool that I can grind and hone. This not only gives me a chance to adjust the geometry, but assures me that I am reaching the actual edge during honing.

To cut properly, the bevel of the inshave must be ever so slightly rounded which allows the tool to enter and exit. Think of a spoon scooping out ice cream, the curve makes it happen.

I like to begin with the back of the blade. A hardware store carborundum burr helps knock out any high spots. I simply hone the surface with a diamond cone, or sandpaper on a dowel, until the high spots shine, then I abrade them with the burr, being careful not to grind too near the edge. What I end up with is like a very shallow hollow grind.


Once the grinding is done, I take some fine sandpaper wrapped around a dowel and chuck it in my drill to even out the surface and then finish off by loading the sandpaper with polishing rouge and going at it until it shines bright and even.



While I try to keep the surface flat, a little rounding will be ground out when I grind the bevel.



Grinding the bevel is easiest if the top edge of the tool lays nice and flat. I set the tool rest nearly flat and grind while holding the tool inverted. If the tool rest is too small or the tool doesn't lay flat, the inshave can be stuck to a plate with rare earth magnets to provide stability.


Once I have a proper grind, I hone the outer edge with small diamond paddles and finish with a leather strop. The leather strop rounds the edge just enough. A few strokes on the inside with a rouged dowel will finish the job.


Every tool, especially old ones, seem to have a sweet spot where the geometry and polish of the tool create optimal performance. I try not to drive myself nuts finding it on the first sharpening. A bit of use will tell me if the edge is too brittle to support the bevel angle or not quite right to work with the angle of the handles. Over time, repeated sharpenings will give me the opportunity to refine the job, and my awareness of the tools' abilities will foster a sense of value and familiarity that I'll feel whenever I reach for it.

Wednesday, April 7, 2010

An Ounce of Frustration

Making things is hard, and maybe it's supposed to be. Most of the time, I feel like it's my job to simplify, demystify and make possible even the most daunting tasks of chairmaking for my students. I take great joy in seeing the results of a good explanation or process. But a simple task has recently brought to mind the experience of learning.


Lately I've shown a couple of students the process of jointing edges for the gluing up of seat stock. I've posted here about the method that I use. It's pretty simple really. But watching students work to master it, I've realized that there is something missing. That something is the countless hours that I've spent learning everything from the feel of the handplane itself to the sharpening, wood technology and perhaps most importantly, the practice.

I keep thinking of musicians, and the process of mastering an instrument or music. No one would dare to think that just picking up a violin would make them ready for the stage, yet with the purchase of some tools, it's easy to mistake that one has acquired the skills that drive them.

So what's my point? It's not that I believe that we should abandon the optimism and boldness that pushes us forward into the unknown, but that we shouldn't be so surprised to find it a strange and awkward place once we get there.

It's easy to measure success of a project by the final results, but perhaps focusing on the small lessons along the way is more appropriate. Watching students confront their frustration and get their foot in the door of a new skill stirs a lot of empathy in me. Sometimes I wish that I could spare them the trials, but then there would be no real chance of success at all.

Tuesday, April 6, 2010

Abundance

With the advent of spring, all sorts of things seem to be happening all at once. We recently went to the annual Woodworking Showcase hosted by the Northeastern Woodworker Association. I managed to get some work done while demonstrating my caliper to the attendees. For those interested, the next production run is in process and I hope to have more soon.


Although there are no tools that I lack for my profession, I still can't resist a rare and well made inshave. I bought this one from Don Flaws at the show. The angle of the handles and curve of the blade are just about perfect, now to convince a manufacturer!


In the next post, I'll show how I brought this tool back into working condition. I gather from the slightly inconsistent bend that this may have been made to order by a blacksmith rather than part of a production run of tools.


Here is the Chairnotes covergirl taking a well earned break on the local mushroom bench.


Before we left, I put a chair in the fuming tent for a client who wanted it extra dark. I couldn't resist this shot. The chair came out of the tent a strange sickly gray color, but after adding the oil and a few days, it became a rich chocolate brown.


And for those following the progress of the animals, here is our little pregnant Maggie (due any day now) learning the ropes of her new milking stand. I'm thrilled to be adding dairy to our food production, especially since the warm weather killed the sugaring season prematurely.

Sunday, April 4, 2010

E-Z Bake Kiln

After 10 years of hard continuous service, I felt that it was time to replace my old kiln with a new, thermostatically controlled model that could be loaded without being a contortionist.

The concept behind the kiln is the same as the old E-Z Bake ovens, without the undercooked cupcakes. By using 300-450 watts worth of light bulbs (sorry, no green bulbs here, we need the heat!), the box easily heats to 120-125 degrees before the thermostat kills the power. Below is Seth putting the box together. We simply made four L shaped legs from strips of plywood and joined them with a strip of wood along the top and about 16" off the floor. The bulbs are house in the space below the lower strip.


To isolate the lights from any combustables, we ran a baffle made from aluminum flashing that hangs directly over the bulbs as well as some aluminum screen to keep debris from the bulb area. The strips of wood support the wood being dried. We used 1" thick celotex insulation to infill the box.


The most common questions that I get about drying wood are, "Do you put it in green?" and "How long do you leave it in?". I avoid putting any green wood in the kiln until it has had at least a couple of days to air dry. If the pieces are larger than spindles, I try to go even longer. Basically, leave parts out of the kiln as long as you can stand it.

As far as the amount of time to leave the parts in, a very accurate way is to weigh the parts and to leave them in until they stop losing weight. This means that they have come to equilibrium with the air in the kiln and will dry no further.


Another factor in drying wood is air movement. This is essential to allow the moisture laden air to escape. Without air movement, the kiln would just be a sort of low power steam box. If I had wanted to get fancy, I could have use some sort of fan or space heater with a fan to get the air to move, but I just rely on hot air to rise and a number of holes in the top of the kiln for air to escape. I also use some holes in the top to set the legs in to dry their tenons, so by having a few extra I get all the air flow I need.

If I was trying to be more gentle in the way that I dry my parts, I'd run the fan with the temperature lower at first and then step it up later. But for me, the air drying does the trick. Besides simplicity, I also like to keep the temp up in the kiln so that I can "set" the wood in my bends at the same time that I am drying other parts.


Here you can see that I used steel "high hat" channel to mount the lights. I wanted to isolate them from contact with any flammables.

Below is the chicken incubator thermostat that controls the power. I have it mounted in the top inside of the kiln. It does a fine job and for cheap! Here is a link to a page on ebay where I bought one.


Here are couple of other kilns. While teaching at Kelly Mehler's School last month, we cranked up the heater in the bathroom and rigged up some racks. It worked just fine. Normally during summer months, the students just use their hot cars, pretty smart if you ask me.


Here is the kiln that Kelly has for smaller parts. It's the same concept, but without the insulation.


Drying green wood that has been split into small parts is a whole lot simpler than I could have imagined before doing it. If you imagine leaving a piece of bread out on the kitchen counter, and how long it would take to go stale and become rock hard, then you can get the timing of drying a spindle.