In nearly all of my woodworking projects, there are curves that can make or break the design. These are almost always curves without a constant radius, so I am relying on what looks “right” to my eye. I really sweat this aspect of the design process.

Acu Arc flexible curves are my favorite tools for laying out curves. French curves in regular and Woodhaven’s giant sizes are also helpful for sections of curves.

I do not like flexible rules or laths for laying out curves because it is awkward or impossible to control the contour in mid-curve. The curve is determined by the endpoints and at least one intermediary point and is then subject to the material properties of the layout device which may not produce the desired contour. I rarely use trammel points or a compass.

To design curves in a project, I start by gathering ideas and drawing in my sketchbook. I refine the promising sketches with scale drawings, repeatedly erasing and redrawing. To produce a full size mock-up, the results get transferred onto wood by measuring the key points and laying out a smooth curve using the Acu Arc. Sometimes I go from sketches to drawing directly on the wood. The mock-up is refined with spokeshaves, planes, and especially rasps.

I spend a lot of time looking at the mock up, leaving it, and returning to see how it strikes me at repeat visits. The bottom line: when it looks right and feels right, it is right, and that is a happy woodworking moment!

I transfer the key dimensions of the mock-up and drawing to make a template in quarter-inch MDF, using the Acu Arc again to refine the final layout. MDF works better than plywood, solid wood, or cardboard since it holds a clean edge and there is no grain to distract my eye or tools. The edges of the template should be square if it will be used on both faces for legs or as a template for router work.

Looking down the curve, as shown in the photo below, is a remarkably sensitive way to see bumps and lumps that must be eliminated to “fair the curve.” Running one’s hand along the curve, like a sleigh ride over the hills, is also a very good way to sense smooth transitions and detect lumps and bumps which must be removed.

The Acu Arc has a natural tendency to produce a curve without bumps as you shape it to your wishes. Then you can hold it on the wood, and trace only a nearby section of the curve with a pencil, hold it further along, trace more, and so forth, proceeding incrementally. It is stiff enough to hold its shape when it is carefully lifted and turned over to form the mirror image curve on the adjacent face, as is usually done for making legs. It is made of translucent colorless plastic but I would prefer opaque plastic that would show the curve better against the background of the wood.

The AcuArc is available from Highland Hardware in 24″, 48″, and 72″ lengths, and from Lee Valley in 18″ and 36″ lengths. (The top picture in the online LV catalog shows the pencil too far from the hold-down hand – the Acu Arc will move.)

I label the templates, save them, and sometimes reuse parts of them in other projects. In due time, a style develops, and, who knows, maybe someone will notice.

First, the bad news. Pearwood (genus Pyrus) is difficult to dry without distortion and the lumber often contains large splits, knots, and other defects. It is expensive and hard to find, especially in large pieces that are not loaded with defects.

But oh, the good news! Pear has a dreamy fine-grained, silky-looking texture with understated but exciting color. The best I can do in words is to call the color a muted pink/salmon, sometimes a pinkish brown. Almost all commercially available pearwood that I have come across has been steamed during processing to enhance the color and reduce stresses in drying.

The domestic pear that I have bought locally has tended to be fairly uniform in color with little or no curl figure, and a density not much greater than cherry or walnut. The top photo below shows a pair of pink-salmon boards from the same tree. Note the subtle shimmer curl in the front board. The lower photo shows a board from another tree which has interesting purplish red streaks.

All of the wood shown in this post is from my shop. It has been surfaced only by the thickness planer with the exception of the door panel in the photo at the end of the post. The photo color is very close to real and close as I can get. Some pieces are portions of boards purchased over 15 years ago. Please keep in mind that I am writing these posts based on my personal experience with the wood, and, since pear is particularly variable, others woodworkers will surely have different experiences. Pear is one of those woods that, if I see some excellent stock in person, I’ll buy it even if I do not have any immediate plans to use it. I know its time will come.

I have a pile of German pear that is much denser, has deeper color, and more streaks and figure than the boards above. I resawed all of it and it took a long time, at least several weeks as I recall, to settle out of its tendency to distort. Three examples from that lot, pictured below, show a range of color, streaks, and curl. Beautiful! Once at peace, all the pear that I have used has been well-behaved and quite stable. I have not been able to find shrinkage data.

Pear is not problematic to saw or glue. Its beautiful fine texture demands a hand-planed finish. The blade must be at peak sharpness with a carefully cambered edge because any blade defect will show up prominently on the wood surface. I needed a bevel-up smoother with a high attack angle for the German pear. Likewise, in cutting joints, pear reveals any and all boo-boos.

Finishing pear is a study in “less-is-more.” Oil or varnish, in my opinion, kills the wood giving it a greasy look. No finish or just some wax would work. To get more protection, I prefer a water-base poly-acrylic which imparts as little change in color as possible and preserves the lively look of the wood.

Enjoy and good luck with pearwood if you decide to use it in your work.

Over the coming weeks and months I would like to write some posts about my favorite woods from a personal, hands-on perspective. The internet woodworking world has an abundance of discussion about tools, ironically to the relative neglect of the magnificent gifts of nature on which we use them.

First up is big-leaf maple, Acer macrophyllum. The natural range of this species is the North American west coast from California to British Columbia. Synonyms include Oregon maple, Californian maple, and Pacific maple. To distinguish, “hard maple” is usually Acer saccharum (sugar maple) and “soft maple” is usually A. rubrum (red maple) or A. saccharinum (silver maple).

For this East coast woodworker, the magic of the internet is the source for big-leaf maple. The first place I turn to is Northwest Timber, run by Lewis Judy, the source for the wood pictured in this post. Their wood is properly processed and cared for, and I can confidently expect that what I see is what I will get.

I can’t wait to get this panel into a project:

Why source big-leaf from 3000 miles away when I can easily find hard and soft maple locally? Well, for starters, I like its looks – and it has lots of different looks. Curly big-leaf is my favorite. I prefer it with an inviting soft, ropy curl, with wavy annual ring lines, as distinct from the tight, regimented fiddleback curl seen in the “best” hard maple boards, which seem somewhat aloof to me. I also like the warm golden-tan color of big-leaf which is enhanced with a wiping varnish finish – I usually prefer gel varnish. It also never seems to have the gray tinge that often plagues soft maples.

Oh, but there are so many more faces to big leaf! Unfigured, it still looks good, often with just a little wiggle to the annual ring lines to give it subtle character. Quilted figure can be mild to knockout, and some may like the extreme bubbly-looking “popcorn” figure. Big-leaf heartwood, “redheart,” can have a beautiful variety of subtle colorations. Like other maples, it produces a variety of interesting spalted appearances.

Big-leaf maple is softer and easier to work than sugar maple, about the same as soft maple in that regard. Still, it is plenty strong and dense enough for tables or any other furniture. It saws easily by hand and generally without burning on the table saw. Planing, not withstanding heavily figured boards, and gluing are not problematic. Heavily curly boards can be properly sanded to produce a final surface which, under wiping varnish, is indistinguishable from hand-planed. (Really, it’s OK, I tested.)

Forest Products Laboratory data show the density and hardness of big-leaf are similar to those of soft maple and significantly less than hard maple. Its volumetric shrinkage and tangential/radial ratio are more favorable than those of soft and hard maples. This is definitely appreciable and significant in the shop in comparison to hard maple. All in all, big-leaf maple is a friendly wood to work.

And a lot of fun to choose!

[My endorsement of NW Timber is unsolicited and unpaid. I just like their wood.]

Gimlets can be handy tools especially when you need to bore a small hole and the usual drilling tools cannot fit in a tight space. I usually find myself using them if I’m in a jam, meaning that I need to drill a hole that I should have made at an earlier stage in construction. I find gimlets useful in small diameters, from 5/64″ to 5/32″, and mostly use them to pre-bore for screws.

The problem is that gimlets do not work very well – they tend to split the wood. I am referring to the commonly available gimlet with a screw point followed by drill flutes further up the shaft. Lee Valley, Highland Hardware, Garrett Wade, and others sell what appears to be the same set of seven for about $14-$15.

For the record and to distinguish, there are other, fussier-looking, more expensive types of gimlets that more resemble a tapered drill bit, some meant to be used in a brace, that are less widely available and not dealt with here. There is also a Japanese gimlet, the kiri, that resembles a miniature sharply angled spade bit on a tapered dowel handle that is rotated between the palms to bore a hole. Still another tool altogether is the very useful brad awl or bird cage awl.

The design of the common gimlet, pictured above, causes the screw threads to feed aggressively into the wood and squeeze past the wood fibers while doing little, if any, actual severing of the fibers. It’s not really much improvement over just pounding a round nail into the wood.

However, consider the design of auger point screws, shown below, such as the type used for pocket-screwed joints. These break some wood fibers as they are driven and so reduce splitting. They do not, however, appreciably clear chips from the hole because the screw threads are not designed to do that. What if the gimlet screw point was altered to mimic an auger screw point so it could cut fibers, and pass the chips onto the drill flutes so they could be cleared?

I made this alteration to the points on my set of gimlets. I found that the edge of a Japanese feather saw file (hatsuke-yasuri) did the job quickly and well, even on the 5/64″ gimlet, and better than a diamond paddle or a triangular Western saw file. I cut two slots on each gimlet, 180̊ apart.

The 75 mm “full cut” Japanese file that I used:

Does it work? Yes, fairly well and certainly a big improvement over the unaltered gimlets! The modified screw point cuts some fibers, makes boring easier, and produces some chips, although the chips don’t get cleared very well by the drill flutes. To compensate, I simply periodically pull out the gimlet to clear chips. Splitting is virtually eliminated. 

This simple modification turns a frustrating tool into a life-saver in a bind. In fact, I’ve gone from almost having given up on these tools to valuing them enough to make a nice little holder for them which attaches to the inside of a door of my hand tool cabinet.

Addendum: (10/21/10)

By “fairly well” I mean that gimlets still have their drawbacks. They are, after all, very simple tools that are substitutes for more mechanically sophisticated tools that are preferable – like a drill. So, in the context of a gimlet, I think I can say that this modification makes them work, here goes, “well!”

It helps to use the Japanese file to create a clean slot with an approximately 90° attacking edge, as pictured. This edge meets the wood aggressively and breaks the fibers. A sloppy “V” groove would have, in effect, a relaxed “rake” angle to meet the wood and thus be less effective.

Following up on the problem posed in the previous post, here is how I managed this board. Most important, I proceeded step by step, watching the wood. The procedure below may seem complicated, but it really is simply a matter of understanding wood and using good sense.

Before doing anything else, it pays to perform the casehardening test. This will require cutting an inch of length off the end of the board and sawing out the core of the offcut to create a long “U” shape. Please refer to the method described in an earlier post. This board, like most thick stock, had some casehardening stress in it.

Starting with rough stock nearly 1 ½” thick and about 9″ wide, the final thickness at the center of the 25″ length will be just under 11/16″ and, at the outer ends, just under 1 3/16″, for a curve depth of ½”.

The diagram is only roughly to scale. It really is intended to give a qualitative sense of how the board was managed. The numbers in the diagram refer to the steps discussed below.

1. I investigated the board by skimming the faces on the jointer just enough to decide if the board will look nice and to choose the show face which will be the curved face on the outside of the cabinet.

2. The opposite (inside) face was hit-or-miss jointed enough to establish flatness. This leaves some rough areas remaining, but enough of the face is smooth and flat to serve as a reference for marking out the curve. At this point, there is less than 1 3/8″ of thickness remaining. I also did a light pass through the thickness planer (with the flat side down, of course) to get a better look at the show side and to estimate how much thickness would be surviving.

3. I sawed the curve with the bandsaw. The layout line was drawn almost up to the surface of the board at the ends. (I had left an inch or so of extra length at each end.) I sawed away from the line, guided by a second line drawn less than 1/16″ away from the original line. This allows for clean up later.

Because substantial thickness was now removed from one side of the board, it promptly distorted so the flat side wasn’t flat anymore.

4. I then removed wood from the inside face which neutralized some of the distortion and re-established the flatness of this face. I did this mostly by hand planing which gave me a chance to keep an eye on things as I went along.

I then cleaned up and refined the curved face, rechecking the flat face as I went along and making minor corrections as needed. At this stage only small quantities of wood were being removed so only minimal correction was required.

The board now sits on stickers as it awaits its role in the construction of the cabinet.

Despite all of this forethought and care, it still helps to have some luck with wood, but it’s not so wicked after all.

It’s really not fair that I say that about wood. After all, I am forever cognizant of one of the first few sentences of Bruce Hoadley’s Understanding Wood : “Wood evolved as a functional tissue of plants and not as a material designed to satisfy the needs of woodworkers.” We cannot cut down the tree, cook the wood, and expect it to do just what we want.

Understanding is indeed the key to a successful relationship with wood as we work with what it is, rather than what we might wish it to be. One of the prime reasons a project can fall short of expectations is the failure to anticipate insidious changes in the wood.

For the top board of a cherry wall cabinet, I wanted a lengthwise curve in its thickness to produce an appealing motif borrowed from the Japanese torii gate. Starting with rough stock nearly 1 ½” thick and about 9″ wide, the final thickness at the center of the 25″ length will be just under 11/16″ and, at the outer ends, just under 1 3/16″, for a curve depth of ½”.

A simple approach would be to joint and thickness the rough board to a bit more than 1 3/16″, then cut and smooth the curve on one face. Done, right? Wrong. Removing a substantial thickness from one side of a kiln-dried board is almost sure to distort it, transforming the opposite flat face that was previously true into a potato chip that will wreak havoc with subsequent attempts at joinery.

We know from resawing wood that most boards retain some internal stress from casehardening. This usually causes the halves of a resawn board to cup toward the inner face. This is not always the case but there is a test for it. This is not a problem of moisture exchange. (Though that could also be present as another issue.) The stresses present in the dried wood cause it to occur even in a board with uniform moisture content through its full thickness. The distortion happens immediately after the board is resawn.

The photos below show the offcut within minutes after sawing. The outside face was flat before sawing. With that face placed on the table saw top, it can be seen that the piece has curved toward the inner (sawn) face in both along its length and across its width.

I’ve left out some steps which I will show in the next post. With this board, I did not have much extra thickness to work with after getting past the rough sawn surfaces, so I needed to anticipate what the wood had in store and have a good plan going in. I will detail the solution in the next post, though I think most readers will be one step ahead of it.

Before using this unimposing little plane I was doubtful that it could get much work done but having put it to work in the shop I am convinced that it really performs. It brings an effective combination of toughness and control to curved work and hollowing.

The plane has a bevel-up A2 blade bedded at 20̊ and a 3 1/2″ long double convex sole with a shallow 27″ radius along its length and a steeper 3″ radius across its width. The blade is secured with a simple cap and thumbscrew mechanism and is adjusted by hand or by tapping with a small hammer. Nothing complicated with this tool, it goes right to work.

The “squirrel tail” handle is the key to controlling the plane. The dome of the tail nestles in the lower part of the palm of the hand while the fingers surround the plane’s body with the index finger settling on the round depression at the front of the tool. This allows one to adjust and balance hand pressure toward the front or back of the tool as needed in order to engage the blade to cut on a curved surface. I find this makes it easier and more natural to control than other convex sole tools such as a spokeshave.

The mouth opening is quite wide which, along with the curved blade, and lightweight handiness of the plane, allow quick back and forth strokes, much like the action of a scrub or jack plane. I find this tool is best used as a sort of mini jack plane for hollowing. The photo below shows an example.

I bandsawed a shallow lengthwise curve into a 27″ long piece of plump 5/4 9″ wide cherry which will be used as the top of a wall cabinet. I used the convex sole plane to efficiently remove the bandsaw marks and refine the curve. The plane felt like an extension of my hand allowing me to work intuitively as I formed the curve to my liking. The shallow scallops that remained were easily removed first with a curved Surform rasp followed by an Auriou curved “ironing rasp,” hand scraper, and sandpaper.

[I will mention that removing a substantial portion of wood from one side of a board like this is likely to create problems as the internal stresses in the board become unbalanced. I plan to discuss in a future post how I anticipated and worked around this sneaky problem.]

While I’m very happy with the L-N convex sole plane and recommend it, I would consider some design changes if I could have my preferences. It is a bit undersized for medium scale work, although an increase in size might sacrifice some of its handiness. A slightly larger radius across the width of the sole would suit more of my work. Perhaps a choice of sizes and soles could be made. Finally, knurling or a coarse surface on the widest parts of the sides would allow a better finger tip grip. I guess I can add that myself.

This tool review is unsolicited and uncompensated.

Thank you, Heartwood blog readers

I started this blog two years ago believing that woodworkers have a lot to gain from sharing information and ideas in this format. That belief has been reinforced, the readership has grown far beyond anything I anticipated, and there has been much gracious and encouraging feedback. This is not a farewell, just a juncture at which to say, “Thank you,” dear readers.

Of course, you have a wealth of choices in the internet woodworking world, so I am very appreciative of the time you spend here in this little corner of it. I hope the Heartwood blog has advanced your woodworking and spurred your enjoyment of it.

I will continue to present thoughtful, useful content. The topics arise from the sawdust and shavings of my shop, devoid of hype and armchair pretenses. The writing will continue to be largely technical though often laced with reflections and sentiments that accompany my woodworking.

If you are even slightly inclined, do leave comments on the posts, please. Other readers and I would like to hear from you. I must continue to hold all comments for approval because even though the Akismet program filters out many thousands of spam comments, some do find their way through.

So far I’ve posted about 45,000 words and 200 photographs, enough to fill a nonfiction book. This is a labor of love and I can only say that I hope to continue to be able to devote the time.

For now, thanks for reading and happy woodworking!

Rob