This is a pile of parts for one Anarchist’s tool chest class.
One of the most difficult things of late has been sourcing my beloved sugar pine for tool chest classes. It’s “imported” from the West Coast – and with lumber companies struggling to fill demand and the still-high cost of shipping, it has been impossible to get. I’ve heard time and again from my local supplier that “we expect some next week,” but no joy. So I had to find another solution.
I looked for Eastern white pine (another good tool chest choice that’s usually easier to get around here than sugar pine), but all I could find was #2 (at best), and usually too thick (I like a full 7/8″ for the “Anarchist’s Tool Chest” builds). Another decent option is poplar – but it’s harder to cut and chop, so it takes longer for students to work their way through the 52 dovetails that go into this chest (if you go the poplar route, 3/4″ is thick enough – no need for the additional weight). I’ll use poplar for the ATC class if that’s all I can get – but I don’t like to (though it is typically an economical choice). I want my students to have nothing but success, and that’s easier to achieve with a softer wood that has a better “mash factor” – by which I mean you can get away with squeezing a few joints together that really shouldn’t go together because they’re slightly tight, or the cuts aren’t quite straight. Everyone needs a little forgiveness now and then, and poplar has less of it to give.
So, on the recommendation of Jameel Abraham of Benchcrafted, I got in touch with the Amana Furniture and Clock Shop. (Amana Colonies is in Amana, Iowa – it’s where Benchcrafted holds Handworks which, by the by, is now scheduled for September 2023.) Amana cuts and kiln dries linden from the property for use in the shop’s own projects, and Jameel thought there might be some to spare some for tool chest kits. He put me in touch with Chris Ward, sales and manufacturing manager, who worked with his team to make a sample kit for me to try out earlier this year.
I was sold, and I ordered 13 more kits – seven for the class that concluded yesterday, and six for my February ATC class (to save money on shipping). I can’t make the kits for less than Amana charges (and right now I can’t even get material) – and they have better facilities and industrial-sized equipment for making the multiple large panels for many chests all at once. Plus they have more than one person to do it! And to be frank, they can produce better large panels than can I, because they have a panel clamp system and a wide-belt sander to level the seams if need be. I have K-bodies and handplanes (which work just fine – but not quickly when there are 28 panels to glue up and flatten). I did the final squaring and sizing in our shop…because I’m anal retentive. But perhaps for my next order, I’ll have their team do that, too; my back is not getting any younger.
The prepared wood arrived in crates – I’m glad it was a sunny day.
But I wasn’t completely convinced on the linden (which is also known as basswood and American lime) until we started cutting the joints. With experience now in a class setting, I actually think it is in some ways better than pine – there are no sap pockets or streaks, so saws don’t get gummy and therefore cut more smoothly for longer (no need to stop and clean them), and it’s a little less fragile on the corners. That makes sense, given that it’s slightly harder on the Janka scale (sugar pine is 380; linden is 410) – but not so much more dense that it weighs significantly more. (I meant to weigh one of the finished linden chest for comparison…but I forgot. But I did help lift four of the six into various vehicles, and I’ve lifted dozens of pine ATCs into cars and trucks over the years, and I noticed little weight difference. I’d guess maybe 5-10 additional pounds.) It also takes paint nicely – much like pine and poplar. I tested General Finishes “milk paint” on an offcut, and was pleased to find that two coats will likely be sufficient (at least in dark blue).
This is two coats of (hastily applied) Twilight (yes, blue).
My only complaint is that linden has little odor; I missed the scent of the pine. When seven people are working hard, well, a bit of natural pine air freshener is a bonus (I’ll hang a pine air freshener under every bench for the next class!). And the students did work very hard – everyone left with a chest just about ready for final cleanup (finish planing/sanding) – and they all looked great.
The author has spent his entire life as a professional woodworker and has dedicated himself to researching the technical details of wood in great depth, this material being the woodworker’s most important resource. The result is this book, in which Richard explores every aspect of the tree and its wood, from how it grows to how it is then cut, dried and delivered to your workshop.
Richard explores many of the things that can go right or wrong in the delicate process of felling trees, converting them into boards, and drying those boards ready to make fine furniture and other wooden structures. He helps you identify problems you might be having with your lumber and – when possible – the ways to fix the problem or avoid it in the future.
“Cut & Dried” is a massive text that covers the big picture (is forestry good?) and the tiniest details (what is that fungus attacking my stock?). And Richard offers precise descriptions throughout that demanding woodworkers need to know in order to do demanding work.
In order to design successful structures we furniture makers and other woodworkers need to develop some understanding of wood’s strength. It is common knowledge amongst experienced woodworkers that some woods are stronger than others; we quickly learn both European oak or American white oak are stronger than balsa wood, or ash is a better material for hammer shafts than European red pine, i.e., Scots pine. But the question to pose is, “What determines the strength of wood?” The answer lies in the material’s ability to resist stress, and the strain or deformation resulting from the stress along with the material’s ability, or inability, to recover its original form when, or if, the stress is removed. Both stress and strain are definable and measurable.
Stress, more precisely described as unit force, is the amount of force acting on a defined area; strength is the ability of a material to resist unit force. Stronger materials resist unit force better. It’s relatively easy to work out the unit force a bookshelf must resist. To do so, weigh the books carried by a shelf to establish the load (L) and calculate the shelf’s surface area (A). The numbers for the following sample calculations came from a convenient load of books on a shelf in my home.
• 42 books weighed on domestic scales = 32 kg (or 71 lbs). Shelf dimensions: 870 mm x 295 mm = 0.26 M² (or 34.25″ x 11.61″ = 2.76 ft²). • To calculate the unit force (UF) applied to the shelf, divide the load (L) by the area (A) thus: L / A: therefore 32 kg / 0.26 sq m = 123.01 kg per sq m UF. • Working in pounds and feet calculate: L / A: therefore 71 lb / 2.76 sq ft = 25.72 lb per sq ft UF. This can be converted to pounds per square inch (PSI) thus: 25.72 / 144 sq in = 0.18 PSI.
Engineers and scientists seek greater accuracy than the methodology used here of weighing with bathroom scales and rounding results to two decimal places, but the methodology and values used illustrate the principle. Additional calculations using the source data shows the shelf carries approximately 11.04 kg per 300 mm length, or approximately 24.69 lb per foot length. My experience is these numbers are typical; for many years I have used 25 lb per foot length or 11 kg per 300 mm length as standard bookshelf loading. There are exceptions furniture makers have to design for, but those exceptions are generally readily spotted, e.g., a request to create shelving for a collection of large-format art books immediately triggers a reaction that the shelving should be stronger. For example, you might use 18 mm thick solid oak instead of 18 mm thick oak veneered MDF, or extra reinforcement is necessary, or the shelf span should be shortened, or a combination of all three measures may the right solution.
It is possible, where necessary, to calculate the load beams are likely to experience in use, then to design for and build in enough strength for the intended load, plus an additional safety margin. Situations where woodworkers are most likely to recognise the necessity for such calculations are in the building or construction industry, e.g., safe loading of wooden floors and roof truss design. Indeed, there are calculations, formulae and standard load tables used by structural engineers to account for the load-bearing requirements of such structures.
Posts, such as music stands, easels, benches and table legs, chair legs, parasols and umbrellas, cabinet sides etc., all experience loads or stress. In many cases each individual leg in a chair is more than strong enough to carry the weight of a person; the design challenge for a one-legged pedestal chair is finding a way of supporting the pedestal so it doesn’t fall over when applying a downward load and, further, making it strong enough to cope with any torsional (twisting or rotational stress) and horizontal forces a pedestal chair leg must endure.
Stressed parts, i.e., loaded parts, experience strain and strained parts deform; strain is defined as unit deformation. If you lightly tap the surface of a piece of 50 mm- (2″-) thick wood with a hammer the wood directly under the hammer head compresses, i.e., the thickness reduces and this illustrates unit deformation. After a very gentle tap with a hammer, the wood will regain its original shape and form showing the wood is elastic and it can recover if not unduly stressed. Without controlled laboratory conditions it is hard to measure the amount of compression but under a light load as just described let us assume, for the purpose of an example, the unit deformation is 0.2 mm (0.00787 inches).
Calculating the unit deformation caused by the impact of the hammer head requires the sum: Dimensional Change / Original Dimension
Using the figures given in the hammer-tapping example, i.e., original plank thickness = 50 mm and the amount of compression = 0.2 mm the calculation is: 0.2 mm / 50 mm = 0.004 millimetre per millimetre (mm/mm). The end result is expressed here as millimetre per millimetre, meaning 0.004 millimetre (unit deformation) per millimetre (of thickness), the same proportion as 0.2 / 50. In reality the expression “millimetre per millimetre” is not necessary from an engineer’s perspective because the proportion of deformation, i.e., 0.004 to the original thickness of the piece of wood is the key information. The same rule applies when you work in any other unit of measure as long as the same units are used on both sides of the equation, e.g., inches divided by inches, metres divided by metres, miles divided by miles etc. The following sum uses inches but note the end result is still 0.004.
After converting the metric measurements used in the previous paragraph to three decimal places in inches, the sum and the result are: 0.008 in / 2 in = 0.004 inches per inch (in/in). Dimensional change is 0.004 inch per inch. Returning now to hitting the wood with a hammer, tapping the surface of the wood harder and harder with the hammer will eventually lead to one of those blows leaving a noticeable and permanent dent in the wood. This rough and ready experiment demonstrates Hooke’s Law.
“Hooke’s Law states that the strain is proportional to the stress” (Kollman and Côté Jr., 1968, p 292). Further clarification of Hooke’s Law leads to saying in wood, in common with other materials, stress and strain are proportional up to a particular point. Specifically, that point is the proportional limit. Beyond the proportional limit of the material, increased stress leads to disproportionate strain, i.e., greater deformation, until the material reaches a stage where further stress leads to failure.
Another way of describing this phenomenon is, up to its proportional limit, a material exhibits elastic properties whereby applying a load causes it to deform, and on removing the load the material completely recovers. Beyond the proportional limit of a material, adding bigger loads causes the material to become plastic rather than elastic, and it cannot recover completely after removing the stress and eventually additional load causes the material to fail.
Figure 14.19. The elasticity of two types of wood, one stiff wood represented by blue lines, and a more flexible one represented by red lines. Generally, stiffer materials are stronger than more flexible ones. Up to the proportional limit, increasing stress (X axis) results in a proportionate increase in strain (Y axis) from which each of the two pieces of wood in this illustration can recover. The slope of the straight-line portion of the graph represents the modulus of elasticity. A steeper line indicates a higher modulus. Stresses above the proportional limit result in greater proportional strain, permanent deformation of the material and permanent set. For instance, a bookshelf loaded beyond its proportional limit takes on a permanent bend. Beyond the proportional limit, the greater the load, the greater is the permanent distortion until the point of failure. In most wood species the proportional limit is generally between 50 percent and 65 percent of load leading to complete failure.
Within the elastic range of a material (up to its proportional limit) the ratio between applied stress and the resultant strain is a constant with this ratio being the modulus of elasticity (MOE), also known as Young’s Modulus. “[It] is a measure of … stiffness or rigidity. For a beam, the modulus of elasticity is a measure of its resistance to deflection” (Forest Products Laboratory, 1955, p 68). Figures 14.18 and 14.19 illustrate the proportional nature of strain in response to added stress where incrementally greater loads act on the centre point of a shelf. This kind of load is a static load.
Figure 14.23. A stress/strain graph derived from readings taken during the experiment shown in figures 14.20, 14.21 and 14.22.
A rubber band is another item illustrating Hooke’s Law. The law, in the following description, is demonstrated visually rather than measured scientifically. If you hold a rubber band between your fingers and stretch it gently followed by releasing the stress, it will recover its original shape. Successively increasing the strain stretches the band further, and a common visual sign the band is approaching its recoverable limit is increased whitening of the stretched rubber. As the band has to cope with increasing stress it loses the ability to recover and return to its original shape, and further stretching eventually causes the band to break. The elastic band experienced a tension force that stretched it whereas the previous example, a plank of wood, experienced a compression force through being hit with a hammer head. In both cases the important point is the material experienced a stress (loading) resulting in strain. And in both cases the stress and strain are proportional up to a specific point; beyond that point increased stress leads to greater strain. Stress is a force that can act in more than one direction – stress may in fact occur in multiple directions at the same time, e.g., a part could simultaneously experience compression, tension, and shear stresses (see figure 14.24).
The strength of a material determines its ability to resist stress: an 18 mm- (3/4″-) thick oak book shelf 610 mm (24″) long is significantly stiffer than an MDF shelf of exactly the same dimensions. As a consequence, when both shelves are stressed by loading the same weight at their midpoint, the oak shelf exhibits less strain indicated by less deformation, i.e., it does not bend as much. In addition, the oak shelf is able to carry significantly more weight than the MDF shelf before it fails completely.
A simple static bending load experiment to demonstrate Hooke’s Law. Static bending occurs under a constant load or when a load gradually increases. The set-up is a rudimentary partially fixed end beam with a knot-free softwood fence paling (picket) screwed down at both ends to span between the two sawhorses. The distance between the bottom of the paling and the ground was measured and noted. Concrete blocks, each weighing approximately 10 kg, were loaded onto the paling, and the distance between the paling and the ground measured. This was followed by removing the blocks, and a note of the distance between the ground and the paling taken again. The sequence was: Add one block, measure, remove the block and measure again; next, load two blocks, measure, remove the blocks, measure again, etc. The paling recovered to its original condition up to the point where adding and subsequently removing 9 blocks (~90 kg); this was the “proportional limit” of the material. Loading additional blocks led to greater bending of the paling under the load, and ever greater permanent distortion (permanent set) of the paling after removing the load. Complete failure of the paling occurred with a load of 13 blocks (~130 kg). This experiment did not represent true scientific testing; it is evident, for example, the outermost feet of the sawhorses had lifted off the ground in the middle image, which compromises the accuracy of measurements gathered. However, the accompanying graph, figure 14.23 derived from the experiment, illustrates Hooke’s Law reasonably effectively.
We’re so hard-core at Lost Art Press that our first question to accountant candidates was “are you a woodworker?” OK – not really. But it turns out our accountant really does spend a fair amount of time in the shop! That’s his work shown above, and he wrote the below.
– Fitz
The first question is always “how long did it take to make that?” I pondered the question for a few moments and answered “well, I started this bowl in 1977.” While it didn’t actually take me 45 years to make the Rainbow Bowl (from recycled skateboard decks), it’s certainly the result of an early life passion for everything skateboarding.
In 1977 I was 13 years old and my family had recently moved to a new neighborhood where hundreds of homes were to be built in the next several years. Where others saw a burgeoning neighborhood, I saw an unlimited supply of scrap construction lumber perfect for making skateboard ramps and jumps. This might where my lifelong woodworking hobby found me. It could have started out by simply nailing a piece of plywood to a 2×4 to make a basic skateboard ramp. I don’t really know for sure where it started, but I’ve been making things from wood since as long as I can remember.
Fast forward 45 years and I have a house full of personally handcrafted treasures, from a large kitchen table, to a dining room buffet, to lamps to shelves full of what a friend calls “dustables,” and of course a growing number of turned bowls.
As a woodworker, it wasn’t a secret to me that skateboard decks are made from high quality laminated maple hardwood ply, often with the layers dyed in random bright colors. And I’m most definitely not the first woodturner to use skateboard decks in their projects. YouTube has no shortage of videos with folks making all sorts of things out of skateboard wood. My first skateboard project was using old skate decks from a friend’s son to help her create a table and bowl. These were both gifted back to her son. I was pretty happy with how those projects turned out, so with the first pile of used skate decks I was able to acquire, I set my sights on making something unique and colorful.
One of the challenges in woodworking with skateboard decks is that, counter to what you might think, nowhere on the board is actually flat. The board’s ends curve up to serve up as kick tails and the center section is concave. This usually results in troubles gluing the layers together. While ripping a deck board into thinner strips, it occurred to me that regluing those thinner strips into a stack would be perfect working material for a segmented (or wedgies) style bowl. So that’s the direction I went, creating what is now known as the Rainbow Bowl. I filmed the video below that illustrates the process of making recycled old decks into a pretty cool decorative piece. I’m really proud of this piece, and as far as I can tell, it’s a unique take on using this very colorful raw material.
– Mike Sapper
P.S. Please visit my YouTube channel to leave questions/comments on this video – and subscribe to keep updated on future projects, which will include charity events and bowl giveaways.
It’s been a busy couple of weeks…so yeah – I’m being a bit lazy with this week’s post. Today, we’ll take a look at a tiny collection of, well, a couple of tiny things and a few teaching aids.
Starting from the front left, we have calipers inspired by those in the Studley’s tool cabinet – a commemorative tool from Lost Art Press upon the release of “Virtuoso: The Tool Cabinet and Workbench of Henry O. Studley” at Handworks in 2013. We sold only 50 – so if you have a set, you’re one of the lucky few.
Behind that is the far-too-nice-to-throw-away wee box that Chris’s “Unturned Pencil” came in (the maker would no doubt appreciate your noticing the Robertson screws).
Then it’s on to the IBEX violin plane that someone told Chris he couldn’t live without. Turns out he could – but it looks cute on the shelf. Not as cute, however, as the Bern Billsberry teensy coffin smoother (for which we unfortunately seem to have lost the wedge).
Behind the small planes we have a few cutaway views of joints. The round one is inherited from Jennie Alexander, and shows the interlocking rungs that are a hallmark of her chairs (you can learn all about them in “Make a Chair from a Tree“). The rectangular ones are to show students that drawboring a mortise-and-tenon joint really does work (so many skeptics about pre-industrial woodworking technology!).
Plus a few larger tools – a Wayne Anderson sliding bevel gauge (it’s a gorgeous tool – and worth a closer look).
And finally, we have a scrub plane made by John Wilson, of Shaker box supplies fame. I seem to have inadvertently, uh, permanently borrowed it circa early December 2017. Oops.
– Fitz
p.s. This is the sixth post in the Covington Mechanical Library tour. To see the earlier ones, click on “Categories” on the right rail, and drop down to “Mechanical Library.” Or click here.
The U.K.’s Classic Hand Tools (CHT) has organized an auction of David Charlesworth’s hand tools – 100 of the best tools he amassed and used in his storied and half-century woodworking and teaching career. The auction proceeds will benefit David’s wife, Pat.
The tools – each professionally photographed and properly described – are available for preview viewing now, and are arranged by tool type – planes, saws, chisels etc. CHT notes that more information about each tool, and a price guide, will be added as/if that information becomes available. Online bidding begins on November 24 and ends on December 1 at 4 p.m. GMT. These are tools that David actually used, and as such are in excellent condition and ready to put to work.
This is a “best offer” sale – the person who submits the highest bid in the closed auction will be the winner. CHT will ship the items at cost. For more on how to bid and how it works, take a look at any of the items on the CHT pages – at the bottom of each is a link for bidding information. Here again is the link for the main auction page.
– Fitz
p.s. You can read more about David in this post by Christopher Schwarz. Or by simply Googling him. He was a woodworking giant, and is greatly missed.