Archive for the Category ◊ Techniques ◊

Author:
• Wednesday, September 30th, 2020
joinery

Disclaimer: Or what they do tell you but you might not notice.

Perfection is not the fundamental quality or even the goal of good joinery. Instructional promises of “perfect” joints, and especially “perfect every time,” are missing the point.

The skillful craftsperson is always is working within a sensitively understood range of tolerance. Understanding that range, and what lies beyond each end of it, are the keys to excellent work. You practice and refine your skills to develop that understanding and feel. You do not practice with an eye on perfection. The pursuit of “perfect every time” is naive and counterproductive because it misses the point. 

This is generally true in any field. The mason knows the idea is to make a good wall despite the imperfections inherent in every brick. The violinist continually makes tiny variances in the intonation of notes depending on the musical circumstances. I think if you ask a pitcher what is the perfect curve ball, he would say the one that ends up in the catcher’s mitt after the batter swings. 

And yet woodworking joinery seems to often be taught, and woodworking machinery promoted, as if the idea is to make, if you could, a 9000-micron tenon to fit into a 9000-micron mortise. And when you inevitably fail, you are supposed to keep practicing with that perfection as your target. 

I suggest instead that you practice to learn how much deviation to tolerate from flat, straight, square, on the line, etc. Learn how fit can vary and still function and look great. This is not to license sloppy work! Your work can and should be excellent. But learn when and how variance matters. Learn tricks to make small deviations cancel through the building process. Understand the concept of one-sided tolerance. (Please see this post.)

Appreciate too, that wood is compressible and this varies with the species so you must adjust your tolerances. Consider that the ideal (I don’t mean perfect) tenon fit where you gently and evenly swoosh, not force, the tenon into the mortise, and then it stays when you hold the assembly upside down. That involves slight wood compression, and you have to work with that. 

There’s another thing “they don’t tell you.” It is fine to practice making an individual joint such as a mortise and tenon but you have not mastered the joint until you can make it in context such as eight of them working together in a table. The same is true for case joints like dovetails. So, by all means, practice, but practice intelligently, and don’t forget that you have to also practice by making things.

Do not get distracted by perfection. Aim for excellence

Category: Techniques  | Tags:  | 7 Comments
Author:
• Monday, September 28th, 2020
understanding wood

Disclaimer: Or what they do tell you but you might not notice.

Unless you get really good at understanding wood, you cannot be a really good woodworker.

A chef without a deep appreciation for the ingredients will always be at a loss for making outstanding food. You’re a woodworker. You make useful, beautiful things. Wood is your medium. It offers the infinite variability of the biological world, which gives it profound potential in your hands. 

Read the books. Start with Understanding Wood, by the late Bruce Hoadley, and Wood, by Eric Meier. Use the Wood Handbook produced by the U.S. Forest Products Laboratory for reference. Here are some resources.

Observe wood “in the wild” in furniture everywhere. Develop a discriminating eye and taste. See how wood ages. To develop a healthy obsession would not be overdoing it. 

Most of all, get lots of different wood in your shop and mess around with it. See how different species and different boards react to planing, joinery, being four-squared, finishing, and so forth. Understand grain and figure, and how to make the best structural and aesthetic use of them. Be aware of the options in manufactured boards – that’s wood too. 

But Rob”, you say, “Chill out, I just want to make nice bookcases and house stuff in plain old pine that I pick up at the home center. I don’t need curly maple.” OK, great, good work, but which boards do you select? All flatsawn, or should you search through the stack for some rift or quartered stock? What is the moisture content of the wood in the store, and what will happen later? Why is the pine you bought this time acting differently from the stuff you bought last time at the same store?

Bottom line: you must know wood and know it really well. 

The next time you look at a project article in one of the magazines, the wood will probably get passing mention at most. Most woodworking publications, unless specifically on the topic of wood, discuss little about it. But if you want to build something and make it good, think carefully about the wood. Use your knowledge, search widely if necessary, buy carefully, and think it through

A corollary of this imperative is that what works structurally and aesthetically in one wood may not work in another. The wood selection should be integrated into the design and construction plan. The hands-on techniques employed will differ depending on the wood. Except for the design itself, wood selection is the most important stage of a project. 

One more thing: wood can and will disappoint you – sometimes, but more than you might expect. Maybe it turns out to have weird defects, it dresses too thin, or it just doesn’t look like you thought it would next to that other wood, and on and on. 

Don’t just buy more, learn more.

So, yea, get your tools, your shop, your designs, your joinery skills, and even your super-sharp edges, but it cannot be overemphasized: don’t forget to get really good with the wood, and always continue discovering more about it.

Author:
• Sunday, September 27th, 2020
woodworking insights

Disclaimer: Or what they do tell you but you might not notice.

Learning in any field takes place on at least two levels. First, there are the overt knowledge and skills that necessarily dominate the instructional material and the student’s efforts. Yet, there are always the unwritten, perhaps even unsaid, insights without which we never feel truly in command of the field. This is “Oh, now I get the idea . . .” — on the road to mastery. 

With all due respect for the many wonderful woodworking teachers out there, it is difficult to transmit these key points in the environment of most formal instruction, especially written. In fact, these essentials may more often be “discovered” by the student in the quiet reflections of “putting it all together.”

These are the sorts of things that despite all your training, you realize six months into the job. Or that the instructor casually mentions in conversation after class when he sees what an eager student you are. Or that dawn on you during a long nighttime drive back home. These are synthesis ideas.

There is a simple continuing theme of this weblog: I greatly enjoy woodworking and find it meaningful. I want to help you do the same, particularly by discussing matters from a viewpoint that is typically neglected in most woodworking publications. With that in mind, I offer this series of posts to present what I think are pivotal nuggets in the various aspects of woodworking. I hope they help you leap ahead to better woodworking or at least reinforce your woodworking mindset. 

Hey, I’m not so foolish as to think I know it all, so please do comment to share your insights on each of the topics as we go through them. The first topic will be, of course, wood. 

Author:
• Saturday, June 27th, 2020
long-grain shooting board

My new jig for long-grain shooting accommodates workpieces up to 36″, a big increase from the old jig’s capacity of 24″. I was motivated by a few occasions when I had to use the somewhat awkward setup of clamping a long workpiece to a support board and running the plane on the benchtop. 

I have found that shooting a three-foot long piece is really not a problem with a good setup. And the big jig imposes no disadvantages for shooting much shorter pieces. 

My 10/31/19 post is a discussion of long-grain shooting. 

Construction is simple from 3/4″ MDF: The workpiece platform is 6″ wide on top of the base, which is 9″ wide, to make a 3″-wide plane runway that is covered with thick PSA UHMW plastic. I like the Lie-Nielsen #9 but any bench plane would work.

The workpiece is controlled from the front by the end stop, and from the side with clamped scraps. I find no need for an elaborate, screw-mounted permanent lateral clamp board because while it would offer some convenience, it would also limit the functional range of the jig. Top (downward) control is supplied by your hand. 

long-grain shooting board

When shooting a narrow workpiece, such as a door stile, which might temporarily have a convex or concave non-working edge, there is the danger of the workpiece flexing against the straight edge of the lateral control board. The solution, shown above, is to use two separate lateral control boards, each butted against a section of the (non-straight or suspect) non-working edge of the workpiece. 

The cleat at the right end of the jig is an afterthought (you know what I mean: “Doh!”) that allows the jig to be clamped with dogs with a conveniently minimal opening of the tail vise, which is then tightened. 

It works beautifully.

Category: Jigs and Fixtures, Techniques  | Tags:  | 8 Comments
Author:
• Sunday, May 31st, 2020
setting hand plane cutting depth
Click on the photo to see a larger version.

It is not surprising that setting the depth of cut in a hand plane can be difficult to learn. After all, we are dealing with differences of as little as a thou or two with a smoothing plane, and even a heavy cut with a jack plane should have a balanced, efficient setting. 

Ultimately, the best gauge of the proper blade projection is the performance of the plane. You sense the bite of the blade, observe the shavings, and make adjustments.

Nonetheless, you want a good initial setting before the plane is brought to the workpiece to avoid lots of trial and error adjustments after starting to plane. Both the left-right balance and the overall depth of cut must be set. These initial adjustments can be made in two ways: visual and tactile.

To see the blade projection, sight down from the front of the sole at a very low angle with a lamp positioned in front of your forehead. The light will be diffusely reflected from the sole (metal or wood) but not from the protruding blade, which thus appears black. Subtly shift your viewing angle to see the thin black strip of the blade. (As a further optional visual aid, note that light will probably also be reflected from a neatly filed tiny wall at the back of the throat at the extreme sides of the mouth where the curve of the blade camber reveals it.)

The photo at top shows a moderately cambered jack plane blade projection. Click on it to see a larger version.

Adjust the blade for lateral balance with the lever, Norris style adjuster, or hammer, depending on the type of plane. Usually, this is easier to observe and manage with a substantial overall blade projection, which you can then back off to a shallow cutting depth. For a smoothing plane, I make this depth almost nothing and then increase it as needed when I start planing. For jack plane work, I usually go directly to a more aggressive cutting depth. 

For tactile confirmation of the visual adjustment or instead of it, use a small block of wood about 5/32″ thick as shown here. I learned this method from David Charlesworth. I prefer to use the edge, not the corner, of the block to pull shavings from each side and then from the center of the blade. 

testing plane blade depth

As with the visual method, get the lateral balance correct first, then go for a good overall depth of cut. The difference with the tactile method, however, is that it is easier to start with a minimal depth of cut to make the lateral adjustment. The assessment is made by feeling the pull of the cutting edge as it takes a shaving from the little block of wood.

Below is an example of the result. Note that this is to illustrate the principle. In practice, I do not usually bother to turn the plane over to look at the tiny shavings. The assessment is done by feel. You can see that this blade has a nice small camber but the lateral adjustment is not correct. The cutting edge pulled almost nothing on the left side in the photo. 

testing plane blade projection

For smoothing plane work, I’m more likely to use the tactile method because it directly gauges precise small adjustments that may be hard to see. For jack plane work with a moderately cambered blade, I’m more likely to use the visual method because the more prominent blade silhouette makes an adequate adjustment fast and easy.

For planes with a straight-edged blade, such as a rabbet block plane, the same methods apply but you are trying to get an even blade projection across the full width of the mouth.

Category: Techniques  | 8 Comments
Author:
• Friday, April 24th, 2020
dovetail markout

In writings from the 1970s and 80s, Charles Hayward, Ernest Scott and others discuss using shallow saw kerfs to mark the tail layout onto the endgrain of the pin board. The idea is to drag the saw through the tail kerfs, which act as guides. There is no instruction to laterally displace the tail board to compensate for the width of the kerf, and so the intention is to saw to one side of the mark.

I find it difficult to start the cut by following such a mark. Moreover, if the start of the cut is imperfect, it is too easy to become disoriented by the hacked up endgrain surface. I do not like or use this method. 

A better method is to use shallow kerfs to guide the placement and engage the saw as you start to saw the pins. Of course, you must laterally displace the pin board to compensate for the kerf thickness. Otherwise, the sockets will be too wide by the amount of two kerf widths. 

I do not know who first came up with this method. I first saw it on Kevin Drake’s website. More recently, dovetail master Rob Cosman, who mentions that he learned it from The Encyclopedia of Furniture Making by Ernest Joyce, has taught it. I suspect that like most woodworking methods, it has been around longer than we realize. 

In the demonstration photo above, the tail board is shifted one kerf width to the left to prepare for making marks through the kerfs on the right side of the tails. This puts the kerf marks in the waste wood of the sockets on the pin board.

Below, the tail board is shifted to the right for making the marks through the kerfs on the left side of the tails.

dovetail mark out

To gauge the shift, I used a shim that is a tight fit in a kerf made by my dovetail saw. You can regulate the tightness of the joint and/or allow for a margin for error by adjusting the thickness of the shim. Making a slightly thicker shim (say .002″ or a piece of Scotch tape) will make the sockets slightly undersized. This may be good for softer, more compressible woods. 

Make the kerf marks before sawing or chopping out the waste between the tails. This gives you a tighter guide. Note that you have to saw the tails square or at least to a one-sided tolerance.  

You will need a specialized tool to make the kerf marks. With a Western saw, it is impossible to make them on the push stroke, and slow going on the pull stroke unless the wood is quite soft. Japanese saws do not work well for this because the teeth do not extend to the toe of the blade. 

Kevin Drake’s system uses a hawk bill scraper, which acts as a saw with a single big tooth, while Rob Cosman sells a nifty marking tool that is essentially a tiny pull-stroke saw with the same kerf width as his dovetail saw. Note that Drake’s system uses a special dovetail saw with no teeth at all at the toe to aid in registering the saw in the kerf mark. 

Unlike when using a scriber or knife, it is easy to inadvertently shift the tail board when making these pronounced marks in the pin board endgrain. A dovetail alignment board of the sort used by David Barron is one way to minimize this. This tool is a great aid to dovetailing no matter the transfer method you use.  

Another method, is to make a very shallow rabbet (1/32″ is enough) on the inside face of the tail board. This gives a dead-on, steady alignment of the tail board against the pin board. I really like this trick for dovetailing in general and use it especially for wider boards. I recall first learning it from an article by Rob Cosman in Popular Woodworking (April 2006), where he notes that he learned it from Ian Kirby. 

Remember, any method of marking out the pin board goes better if you are working on cleanly sliced endgrain, at least from the table saw or, better, from the shooting board.

So, there you have it: three posts on the critical step of transferring the tail layout to the pin board. I suggest experiment and choose what works for you! My go-to method is still the scriber. I cut my first dovetails 40 years ago but I still like to explore and refine different methods. I’ve only experimented with the kerf mark method, but I may adopt it for some circumstances. I like having options as various woods and constructions favor different methods.

Category: Techniques  | Tags:  | 2 Comments
Author:
• Monday, April 06th, 2020
V point marking knife

Continuing the topic of transferring the layout of the sawn tails to the endgrain of the pin board, the purpose of these posts is not to argue for the superiority of any one method but rather to array the options to help you choose what works best for you and the specific project at hand. I vary my method depending on the species of wood, the type of dovetail (e.g. through or half-blind), and the thickness of the wood. 

V-point knives seem to be popular for this task, especially thin models that can slip in between narrowly spaced tails, such as the beauty made by Blue Spruce. Without a doubt, many highly skilled woodworkers produce excellent results with these tools, but I find it difficult to see the knife line. 

I do not mean that it is difficult to see the fine knife line at first, but when I start sawing across the endgrain, I cannot visually keep track of that skinny line to confidently split it with the saw. Chalking the endgrain is not much help. The scriber makes a V-groove that I can track and split better while sawing, and furthermore allows me to better see how I’ve done afterwards. I also find that a V-knife sometimes catches the side grain of the tail, slicing off a hair of it and slightly dislocating the layout line, albeit in the safe direction. 

Ian Kirby, one of my all-time favorite woodworking teachers, has favored a pocket knife for this task. This is not my preference but again, it is another option to consider. The sheepfoot in your three-blade stockman or a Wharncliffe blade like in this lovely Kershaw would be good choices for this because it is easy to reach the tip all the way out to the base of the tail.

Kershaw knife

One knife that I sometimes use is my modification of a Pfeil #13 chip carving knife. I removed the edge and a bit of the width from all but the first 1/4″ of the blade. I also ground the sides to a nearly flat single bevel. (The Pfeil #3 knife would probably also work.) I find this modified tool very easily reaches to the base of the tail and follows the wall of the tail with very little tendency to slice into it. So, I like it better than a V knife but I still usually have the dilemma of following a pretty fine knife line. 

modified Pfeil #13

What about the roll of blue tape in the photo in the previous post? Mike Pekovich, Creative Director of Fine Woodworking magazine, and a very skilled and thoughtful craftsman, covers the endgrain of the pin board with blue tape. (FW #240) He then knifes the tail outlines into the tape, removes the tape over the waste wood, and saws just adjacent to the remaining pieces of tape, which represent the pins. Clever!

I experimented with Mike’s method. It surely has merit, and some will love it, but I am not comfortable with it. The pieces of remaining tape can move, especially if you knick them while engaging the saw, and when they do move, I’m lost. I also do not feel comfortable with a piece of tape determining the registration of the saw. But give it a try, you might like it. 

Next: using saw kerfs as layout.

Category: Techniques  | Tags:  | 4 Comments
Author:
• Tuesday, March 31st, 2020
dovetail transfer tools

A critical step in hand-cut dovetailing is accurately marking out the second piece – usually the pin board – from the completed first piece – usually the tailboard. 

Sure, to make a good dovetail joint, you have to be able to reliably saw to a line and chisel to a line. You also have to understand the mechanics of the joint to appreciate how to tweak the contact surfaces and where you have a bit of tolerance and where you don’t. But if the transfer step is inaccurate, it’s all a losing battle.

So, let’s look at several options

Keep in mind that all of this depends on several variables including pin width, the texture of the wood, and your personal eyesight, lighting, type of saw, and technique. An effective marking out in cherry using a ripcut dozuki may be difficult in red oak using a Western backsaw. 

chisel point drafting pencil

A plain old pencil seems too crude for the precision required in dovetailing and yet it can work well for some. All of the pencil mark is in the keeper wood, so you have to saw to one side of it without touching it at all. A very clean, consistent line gives the best chance for success. A 2mm drafting lead sharpened on 320-grit sandpaper to a chisel point (above) can produce an almost knife-quality line, especially with 2H lead on a diffuse-porous wood like cherry. That said, a pencil is not my preference. 

Starrett scriber

I’ve used a scriber more than anything else for this job, perhaps because that is what I used long ago while learning (first learning, that is). I prefer the type of point on the Starrett scriber (above), which ends in a small, straight conical taper. Unlike a gradual curved taper, I can clearly tell when the scriber is or is not up against the wall of the tail wood. 

Used properly, the scriber point hugs the wall of the tail wood as it bites into the endgrain of the pin board, without any chance of it cutting into the side grain of the tail as a knife might. Thus, the bottom of the tiny V groove created by the scribe point is exactly under the tail wood wall. 

This works best if the sawn (and possibly pared) surface of the tail is straight and clean. Otherwise, the scribed line will be not straight and therefore probably confusing to follow with the saw.  

I have found the scriber effective in ring porous woods like red oak as well as fine, diffuse-porous woods like pear. The downside is the scribed line is not quite as clean and fine as a knife line. 

Next: a look at different marking knives and more.

By the way, go here for my free 42-page Dovetail Instruction Guide that I wrote several years ago for Craftsy. It really gets down to the sawdust and shavings to lead you to success. 

Category: Techniques  | Tags:  | 2 Comments
Author:
• Sunday, February 23rd, 2020
levelling table legs

In theory, the bottom tips of all four legs of a table should be in the same plane so it can sit on a flat floor without wobbling. Remember, however, the words of Yogi Berra, “In theory, there is no difference between theory and practice. In practice, there is.”

Now, if you made uniform leg lengths and mortise-and-tenon positions, you should have a flat base after assembly that requires no adjustment but stealth gremlins almost always prevent such perfection. 

On the other hand, consider that rarely is a floor flat over the area on which the table stands, so making the four legs true is really just playing the odds. Furthermore, a table, especially a large one, may flex when you place it on the floor to produce an automatic correction. The same goes for chairs. Therefore, all of this is often of no concern at all – in practice. 

For a small table though, this issue may be a significant concern. The small area of floor on which it stands may indeed be flat, the table may not flex much, and it feels creepy when it wobbles a lot. So, let’s look at how to assess this. 

It is best to do this with the top attached in its final configuration, which contains any flex in the frame induced by the top piece.

The simplest method is to put the small table on a true flat surface such as the table saw. If such as surface is not available, you can turn the table upside down and use winding sticks on the tips of the legs. Note that this may introduce error if the frame of a larger table flexes a bit differently than when it is right side up. In any case, for a larger table, I do not go hunting for a very flat floor, which probably does not exist; I just do not worry about the whole matter.

For small tables, I do like to get it pretty close. You can take off the error from the one long leg, as determined by how the table pivots on the flat reference surface, but I prefer to take off half that amount from each of the two long legs.

OK, if you have done everything just right in the shop and now place the table on the floor where it will live, which is not likely to be flat, and it wobbles enough to be annoying, what do you do? Shim it. A layer or two or more of tape such as duct tape is just fine – in theory and in practice.

Category: Techniques  | 4 Comments
Author:
• Saturday, January 18th, 2020
cross-rail joint finished

Dry fit the joint with just two dowels. Using all five dowels makes it remarkably difficult to disassemble. However, check every one of the long grain holes to make sure it is full depth so you don’t get a surprise when finally closing the glued-up joint.

I find it less stressful to glue up in two stages. I apply glue in the holes, and then tap in the dowels in one of the tongued components. I limit the depth of the dowels with a registration block. When this subassembly has dried enough to keep the dowels stable, I complete the glue up by applying glue to the other set of holes, plus a little bit on the dadoed piece, and then push the whole thing together. 

This joint must be clamped from the ends. I have found it strongly tends to stay accurately square but, of course, I check it anyway, and adjust the clamps as needed.

When the glue is dried and conditioned, I plane flush the outer edges. If made accurately, which is very likely if the dowel jig was made accurately, this joint will turn out neat and strong, and it will stay that way.

Much of the work in making this joint is in making the dowel jig, which is reusable for a joint of the same or less width. The joint also works with large width rails because there is no conflict from dimensional change due to moisture cycling.

This has been a good joint to have in my repertoire. You might want to give it a try.

Category: Techniques  | Tags:  | 2 Comments