Author Archive

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
Author:
• Monday, August 31st, 2020
DIY tools

I do not like to use my high-end edge tools for rough and tumble DIY projects where a sharp edge has a good chance of meeting up with a nail. Similarly, precision hand tools such as a Starrett square have no business sliding about in mystery debris.  

So, even though my classy hand tools are fully capable of handling rough jobs, I prefer to use my set of utility tools for most repair work on the Magic House. (“Magic,” you know, because it makes my time and money disappear.)

There are a couple of ways for a serious woodworker to accumulate these DIY tools.

You might buy them specifically for such work. Good examples are above. The little Rali block plane has replaceable blades. It does not seem to be available any more but most any cheap pocket/block plane will do. That cheapo square is actually decently made and pretty accurate. The DeWalt tape is also the one that comes with me on wood buying trips.  

Sometimes, especially early on in learning woodworking, we try to save a few bucks by buying a tool that seems good enough, but later proves to be a poor call for fine work. That is how this old Stanley chisel has survived all these years. It easily sharpens to a decent edge that I don’t mind abusing for DIY work. I replaced the round rasp with a hand-cut version but the cheap one is just fine for enlarging a rough hole in plywood. The screwdriver makes a great paint mixer and general hacking/prying tool. 

more DIY tools

Maybe you did not recognize the value of quality tools, or maybe you just did not know how deeply you were going into woodworking. Either way, an upgrade does not always mean waste. 

The take home point: Do not buy tools for their own sake. A tool has a purpose. Match the tool to the job – the one at hand or even the one to which you aspire.

Category: Tools and Shop  | 4 Comments
Author:
• Friday, July 31st, 2020
case hardened wood test

Other posts here have addressed the issues of case hardening, its effect on resawing, and the problem of excessive case hardening. But here’s a new twist.

To review, slight case hardening is to be expected in kiln-dried hardwoods. Here’s a simplified explanation of what happens in the kiln. Think of the board in cross section. The outer shell loses moisture first, making it want to shrink but it is restrained by the still moist and swollen core. The shell is thus in tension and the core in compression. The shell eventually sets in size, so later when the core loses moisture and wants to shrink, it is in tension while the shell is in compression. This is case hardening

The kiln operator modifies the humidity near the end of the process to remove most of the case hardening but is careful not to go too far and create reverse case hardening, which is not practically correctable. Therefore, there is a bit of remaining case hardening in most kiln dried hardwood boards. It is not normally a problem. 

Excessive case hardening, usually from inadequate air drying before going to the kiln or rushing the wood through the kiln, is a problem. This manifests most notably if the board is resawn. Both halves will cup inward toward the sawn surface and may bow inward a bit along the length. We can predict this with a test fork

It is important to appreciate that this is not a matter of a remaining moisture content gradient across the thickness of the board! It is a physical stress caused by the drying process that releases when it can, which is typically right away or very soon after resawing or removing substantial thickness from one side of the board. 

But how long can it take for the release of tension and consequent distortion of the board to fully manifest? From everything I have experienced (and read), it is mostly almost immediate, or in some cases it can trickle on for a day or so.

But this case is different.

I recently resawed some 8/4 quartersawn sapele. The boards were straight and true with nice, even straight grain. There was absolutely no moisture gradient across the thickness of the boards, as proven with pin meter readings at various depths across the end grain of fresh crosscuts well into the length of the board.

Test forks looked great – little or no inward bend of the tines – so I did the resaw. But after a couple of days, I was shocked to see the tines hooked inward. (The photo above is how they ended up.) The boards themselves distorted over several days. They showed both the classic effects of case hardening, and more disturbingly, some twist. I hate twist. 

The wood seemed to settle down after a couple of weeks, so I dressed the resawn boards but then even several weeks later I could still find a small but significant amount of new distortion, primarily twist! Again, the grain of the boards was nice and straight. Furthermore, they contained no evidence of reaction wood, or other aberrations. The resawn wood was stored stickered and at a steady 50-55% relative humidity.

Why did it take so long for the distortion to fully manifest? I don’t know. Some online research and talking with experienced log millers, though hardly exhaustive, yielded no answers. 

Here’s my little theory. For the mechanical release of tension (that creates the distortion) to occur, I assume the wood fibers have to slide against each other. Perhaps that sliding is just “stickier” and slower to occur in sapele than in most woods. Perhaps related, I note that sapele is among the highest measured woods in shear strength (at 12% moisture content) listed by the U.S. Forest Products Laboratory. (Wood technologists and scientists, please comment!)

In any case, it happened. Wood stresses can be stressful. So, there it is, one more caution to take with wood.

Category: Wood  | 4 Comments
Author:
• Wednesday, July 08th, 2020
router table miter slot

Devoted readers (thank you!) know that I like to keep my router table simple but very capable

The router table is truly a key tool in the small shop but there is a wide range of complexity and cost involved. I admit to being intermittently tempted by router lifts, tracks and slots in the table and fence, bit changes and height adjustments from above the table, and micro adjustability of almost everything.

Yet, my simple set up continues to do everything required. It consists of an MDF top and fence on a 2×4 base, dust collection, and the Bosch 1617EVS held in a dedicated base attached underneath the table. Moreover, the flatness accuracy of the top equals the best tables reviewed in Fine Woodworking magazine #237, and it substantially exceeds most of them. Some of those rigs cost more than ten Bens. 

But what about routing a rabbet or profile on the end of a narrow stick, or, more challenging, a dado in the middle of, say, a 4″-wide rail? I again admit to being tempted by an impressive cast iron tabletop with a miter gauge slot. 

router end grain on router table

For routing on the end of the stick, the workpiece alone gives too little registration against the fence. Therefore, I have usually used a squared piece of plywood or MDF, about 10″ x 12″, to register the workpiece against the fence and prevent tearout at the trailing edge. (See photo just above.)

However, sometimes it is handy to use a miter gauge, especially for a short dado. This also allows me to register the left end of the workpiece against the miter gauge stop for a repeatable task.

Well, there just is not enough depth in a 3/4″ MDF top for a metal-lined track for a miter gauge. (Unlike for a T-track, which is more shallow.) Thicker MDF is an another option but that would mean a new table top that would require a recess to mount the router base. A bare slot in the 3/4″ MDF is also problematic in that it would wear quickly. I could line the slot with UHMW tape but it would be hard to get the width just right to avoid having to adjust my miter gauge bar every time I brought it over from the table saw. 

So, as usual, I turn to the late Pat Warner’s writings for a solution. On page 99 of his The Router Book, there is a simple way of making a temporary “slot” in your MDF router table top. My version uses nominal 1/2″ MDF with adhesive UHMW tape on inside edges. (See the photo at the top.) The outer board is screwed down in the near right corner to give more clearance for the miter gauge head, and elsewhere the boards are clamped.

This allows me to use my table saw miter gauge – the wonderful Incra 1000HD and its adjustable end stop. Note that I do not need to adjust the width of the bar. Instead, I retain the setting that works for the table saw, and then for the router table, simply set the two MDF boards snugly against the bar for a wobble-free fit. A backer board prevents tearout at the trailing end of the workpiece. The router table fence is not functional for the cut itself but is close by for dust collection if possible.

It looks like I just saved several hundred dollars yet again. 

Mmmm, that walnut looks nice.

Author:
• Sunday, June 28th, 2020
DeWalt cordless sander

The DeWalt DCW210 is a cordless 5″ random orbit sander that is powered by the company’s 20-volt lithium-ion battery system.

Smitten with DeWalt’s 20V Max series of tools, it is a bit like dealing with Apple stuff. I know I’m being played but the products are just darned good. 

Handling is excellent. Weight, vibration level, and control are comfortable. With a top grip, the only option, the sander tends to meet the work squarely with no tendency to tip or gouge. At least with a smallish 2.0 amp-hour battery, balance is excellent. The rubberized area enhances the feel, and the on-off switch is easily accessible from the grip position. 

This is a finishing sander, not a stock removal hog. In that context, it has plenty of power. It is similar to my Bosch ROS20VS, if not more aggressive. The DCW210 has a standard 8-hole base with hook-and-loop disc attachment, and runs with a 3/32″ diameter orbit. The brushless motor is very efficient, so I read. It has a variable speed dial, also accessible from the grip position, but I rarely use that option on a sander. 

You’re going to love this as I do: the motor brake stops the motion immediately when you hit the power switch. Hallelujah!

Dust collection with the onboard bag is surprisingly good but of course, no match for sanding with a vacuum hose. (I vacuumed up the tool nice for the photo.) The bag’s good-sized plastic collar and locking system makes it easy to use one hand to detach and attach with a nice positive click. A spring that lines the bag can be compressed and popped to “shake out” stubborn dust. I find it is more useful for allowing a vacuum hose to thoroughly clean out the bag without it being sucked into the hose. 

The outlet diameter will not fit standard shop vac hoses but this does not matter to me because using a cordless sander with a hose would pretty much negate the advantages of having no power cord. So I will use this sander without tails of any sort.

I cannot offer data on how long the battery charge will last. After a while of sanding, I check the charge-level indicator on the battery and replace it if it is low. With just two extra lightweight 2.0 Ah batteries on hand and using the DCB113 charger, I could keep working indefinitely. You can also buy higher capacity batteries but I guess at some point the weight would get uncomfortable. Anyway, this is a finish sander suited for relatively light work. Note that DeWalt charger models vary considerably in their charge time.

I will still use my bigger Bosch 3725DVS (3/16″ diameter orbit) with its cord and a vac hose for heavier work but the DeWalt DCW210 is now my go-to tool for finish sanding. 

This review is unsolicited and uncompensated. I just want to help you choose good tools. 

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:  | 6 Comments
Author:
• Friday, June 26th, 2020
woodworking dust collection

For the 500th post since the inception of this weblog in 2008, I would like to present the Grand Unified Theory of Woodworking. Concocted while emptying my dust collector, this offers deep insight to woodworkers and non-woodworkers alike as to what really goes on in the shop. 

And so: You start with a tree. Then, to produce a masterpiece you merely remove the exactly correct tiny pieces of wood (as shown in the dustbin pictured above) while retaining the exactly correct wood in the workpieces, which you then simply join together. Done. 

I present this ridiculous notion only to make a couple of points, which are hardly original but bear repeating.

The people who see and use what we make almost never understand the effort, time, skill, and expense required to make high-end woodwork. Perhaps this is only due to the nature of the craft – wood seems so accessible to work. More likely, it is partly or even largely the fault of woodworkers (like me). Most of the things we use in our modern world are made in huge numbers by computer-controlled machinery. In some cases, the consumer’s hands may be the first to ever hold the product. I think woodworkers should affably convey an understanding of what goes into our work to those who encounter it. 

Second, we woodworkers are similarly apt to forget that making excellent stuff is really difficult. Not to be whiny, but it is healthy to acknowledge that we are always dealing with some degree of workmanship of risk from which even the gadgetry of modern woodworking does not shield us. As a mostly subtractive process, woodworking can be unforgiving (again, see dustbin). For me at least, I have to remember to go easy on myself, trust my hard-won capabilities, and be always open to improving my skills.

It’s simple, really.

Category: Ideas  | 10 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  | 6 Comments
Author:
• Saturday, May 30th, 2020
wood moisture widget

Wood moves. We all know that. This simple gadget makes the hygroscopic movement of wood readily apparent. It reminds me of what is going on with the wood in my shop, and it’s fun to observe. 

The device is simply an offcut from a glued-up flatsawn red oak panel. The strip is mounted on a piece of plywood, which, of course, will not undergo hygroscopic change in its length. The oak is secured with a screw near one end, while a scale on the plywood with 1/16″ gradations straddles the free end. The strip is freely supported by a tiny brad about two-thirds the length from the fixed end in case the unit is hung horizontally, but I usually hang it vertically on a nail. 

At 8.6% movement across the grain (green to oven dry), tangential to the annual rings, red oak is in the midrange among wood species. The 15″ length of the strip plus the abundance of end grain exposure produce substantial and relatively rapid dimensional change.  

A change in relative humidity (RH) from 35% to 85% (at 70°) is calculated to produce about a 1/2″ change in the length of this strip. I try to keep my shop between 40% – 60% RH year round but even this range will produce about 5/32″ of movement. It is interesting to see what happens when I place the device in another room in the house for a day or two, especially during seasonal extremes.

This type of device can be upgraded by attaching an indicator needle to the end of the strip via pivots that convert its linear movement to an arc movement of the tip of the needle. That’s more bother than I want, and the movement of the strip itself is enough to be easily observed directly without conversion.

I consider the regular humidity meter on the wall to be essential shop equipment but this gadget is a nifty way to stay directly aware of wood movement.

Category: Wood  | One Comment
Author:
• Thursday, May 07th, 2020
workbench height

In a 2011 post, I argued for an empirical approach to determining your best workbench height instead of relying on any formula. The many variables in body characteristics, woodworking styles, and tools necessitate practical testing.

Consider the tasks you do at the bench, such as planing, sawing, and chiseling, and the portion of time and effort you are likely to devote to each category. Then find a workbench, Workmate, or a sturdy table to try the work at different heights created by clamping layers of boards or plywood to the table. Find what feels best all-around. 

Maybe your ideal bench height will change over time as mine has. Recently, after assessing how I was working, and then testing just as I recommend to others, I raised my bench almost two inches to 37″. I feel more comfortable overall, particularly being able to stay closer to a neutral head posture. I can reduce the bend in my neck, which reduces stress on the lower cervical vertebral joints. 

On the other hand, I can feel that the higher bench height transfers more of the work of certain tasks such as heavy planing to my upper back and arms. Fortunately, I’ve maintained good upper body strength, especially in the upper back and shoulders, so I don’t seem to miss the reduced drive from the ground. In fact, firming my upper back as I work actually further removes stress from my neck.

I used long #14 screws to attach a glued stack of Baltic Birch plywood to the base of the bench, replacing the previous riser blocks. 3M Safety-Walk slip resistant tape applied to the bottom along with filler blocks between the bench and the back wall do a great job of keeping the bench stable in all directions.

Assess your stress” and work habits to make your shop time more efficient and pleasant.

Category: Tools and Shop  | 9 Comments