Archive for ◊ September, 2020 ◊

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:  | 5 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:
• Wednesday, September 16th, 2020
1:4 French curves

These useful tools from Veritas are paired sets of French curves. The small and large members of each pair have the same curve pattern in a 1:4 ratio.

This allows you to draft on paper at the commonly used scale of 3 inches = 1 foot using the small curve of the pair and then transfer the drawn curve to the workpiece using the full size curve of the pair. Similarly, you can layout full size mock ups with the large curves, decide which one looks good, then use the corresponding small curve to incorporate the curved element into your design on paper.

Veritas French curves

The curves are made from 3mm-thick 3-ply birch. The largest one is 36″ long. The edges are not as smooth as plastic curves, so you might want to do some light touch up with sandpaper using a block to avoid rounding over. 

There are tiny holes at corresponding locations in each pair of curves that can be used as reference points to transfer a layout from one curve to the other in the pair. Numbering the holes, as shown here, helps keep track of the paired locations. 

1:4 French curves marked up

I often use long, very gradual curves in my designs, so I wish Veritas would also produce paired sets like these with very mild curves. I imagine this could be readily done with a CAD-CNC process. 

The key to using French curves is to mark the end points of a curve, then “fill in” the curve using at least one (usually two or more) additional reference point(s) to guide the placement of the template. Shift the reference points and use various segments of the French curve until the drawn curve looks the way you want. 

Consider using this wonderful rasp for truing curves in templates and workpieces. [If I made a buck from it, I might have called this a shameless plug.] 

By the way, why “French” curves? Beats me, but with a little online research, I learned that French curves are based on segments of the Euler spiral, named for the great eighteenth-century Swiss mathematician. The Veritas curves approximate a common Burmester set, named for German physicist-mathematician Ludwig Bermester (1840–1927). So, why aren’t these types of curves called “German curves?”

Category: Product reviews, Tools and Shop  | Tags:  | 2 Comments