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• Thursday, November 30th, 2017

Record #146 holdfast

Some readers have asked about the blue ring in the top of my workbench. It is the collar for the Record Bench Holdfast #146 (Marples M146).

The #146 is an excellent tool. It holds more firmly than any other holdfast that I’ve tried, due to the grip of the notched stem in the collar, as well as the heavy threaded clamp screw. The maximum reach at its lowest height is 6 5/8″ to the center of the aggressively textured clamp pad, while the maximum holding height is about 10 1/4″.

The downside of the design is having a metal collar in your benchtop, which could present a hazard to sharp tools, even though it is slightly recessed below the bench surface. Despite this, I cannot recall ever crashing a tool edge into it. Still, you would not want to have many of these collars in your benchtop. The placement of my one collar has served well, particularly for chopping dovetails over the right front leg of the bench.

Record #146 holdfast collar

In the photos, you can see some of the several 3/4″ holes used for shop-made low bench stops, Veritas Bench Pups, Wonder Pups, and Bench Anchors. These holes also accommodate the two excellent Gramercy holdfasts that I also use, which greatly expand the range for holding down workpieces. With all of these options and more, this old Ulmia can hold just about anything I ask of it.

As far as I know, the #146 has long been out of production, as has the slightly smaller version, the #145. Old ones can surely be found from time to time on EBay and vintage tool websites, and they are likely to be in very serviceable condition because it is an almost indestructible tool. I bought mine new about 35 years ago.

Category: Tools and Shop  | Comments off
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• Tuesday, October 31st, 2017

Domino joints

The Domino sure makes joinery easy: fast layout, cutting parts directly to length, mortises in a flash, no fussy trimming of tenon shoulders, and no trips to the sharpening bench. This may come at a price, however, if you fall into the seductive trap of machine woodworking, which is letting the limitations of the machine govern too much of the aesthetic and structural design.

Let’s look at some possible frame or rail joints made by the Domino DF 500. The photo above shows the “tenon” half of the joint where the long grain of the Domino matches that of the frame member. The two on the left are fine by me. The third from the left is marginally acceptable. The one on the far right is awful.

A little arithmetic backs up what I think most of us would intuitively see as a waste of potential glue area in that last joint. The flat width of the Domino is 13.7mm, or 0.54″, irrespective of its thickness. With a tenon insertion of about 1″ (half the length of the 50mm Domino), we get a total effective glue area of about 1/2 square inch x 2 (for both sides of the tenon) = 1 square inch. I don’t count the rounded areas because they are not good glue surfaces.

At the other extreme, since the rail is 1 ⅞” wide, a slip joint or full tenon would give about 7 square inches of effective glue area! The demands of the design might not need all of that, but giving away 86% of the potential glue area is too much to sacrifice for convenience. I want my work to last.

How can we increase the glue area, at least somewhat, and retain the convenience and speed of the machine? As an example, in the photo below, on the right, the same 1 ⅞”-wide piece has two slightly overlapping Domino mortises. I simply trimmed the Dominos on their inner edges with a block plane to make them fit.

Domino joints

The piece on the left (the marginally acceptable one in the top photo), as another example, has two mortises that overlap a lot to make one wide mortise, wider than widest setting on the machine. It would be easier to make a loose tenon for this than to divide Dominos.

To get the Domino machine to chain together small mortises into a neat, continuous mortise that has no steps in the walls (photo below), the fence must be exactly parallel to the motion of the bit.

Domino joint

My Domino DF 500 – yes my $800 Domino – did not meet this level of accuracy. The machine cannot be adjusted for this, so I carefully shimmed the fence. That was complicated because the shims have to essentially create a new fence surface that is at a very slight angle to the original one.

I had sent sample mortised pieces to Festool but they told me it was within tolerance. Well, it was not within what I tolerate in my work. This is not a tool review, it is simply an account of my experience with the machine I bought.

Domino accuracy

The general point of all of this is to take charge of your woodworking machines, and not let them lull you into woodworking that you know is second-rate.

Category: Techniques  | 7 Comments
Author:
• Saturday, September 30th, 2017

wedged mortise and tenon

The usual directive is to flare the end grain mortise walls and wedge the tenons against those walls, as in the photo above. With the opposite configuration, which has the side grain mortise walls flared, there is reasonable concern that the wedges might exert pressure across the grain of the mortised board sufficient to split it.

However, there is another important way to consider this joint.

In the conventional configuration (photo above) with a well-fit joint, strength is created by the glue bond of the long grain-to-long grain interfaces, which are not wedged. In the long grain-to-end grain interfaces, which are deficient as glue surfaces, strength is created by the mechanical action of the wedges. Thus, all four interfaces contribute to the strength of the joint.

In the opposite configuration (as in the photo below), the wedges apply some “clamping” pressure for the long grain interfaces, but I would contend that is largely superfluous. At the same time, the long grain-to-end grain interfaces are mostly wasted as strength components.

Therefore, to maximize the strength of this type of joint, the conventional wedge configuration is better. In all cases, I think it is best to clamp across the joint and then insert the wedges.

Now, realistically, splitting is not likely in the opposite configuration with judicious wedging, especially if the joint is not too near the edge of the board. And the multiple mortise and tenon joint is probably more than strong enough in either configuration for its typical applications. Still, it is a labor intensive joint and one therefore tends to minimize the number of tenons, so it pays to get the most strength from each one.

The whole point here is to think about what is actually going on in the design of the joint, and make rational choices.

You can find step-by-step instruction on making this joint in my article, Making Multiple Through-Mortise-and-Tenon Joints, in the August 2008 issue (#170) of Popular Woodworking magazine. By the way, an important aspect of my method is to not use a fully housed tenon board as is often advised.

We should not be too definitive about these matters because each piece has different requirements for strength and appearance, and other factors inevitably influence both. Interestingly, in the same issue of PW, Bob Lang uses dual M&Ts to join shelves to the sides of a bookcase, using an approach very different from mine. Yet, I’d bet his bookcase is still going strong.

[Photo of the “opposite” configuration courtesy of Mark Ketelsen.]

Category: Techniques  | 2 Comments
Author:
• Saturday, September 30th, 2017

Supercut bandsaw blade

Readers of this blog know of my fondness for the bandsaw. More than almost any other tool in the shop, a fine quality bandsaw allows you to upgrade your range of designs and unlock the wonders of wood.

With that in mind, here is my favorite bandsaw blade – the one that is almost always on my 16″ Minimax: the Supercut Premium Gold 1/2″, 3 tpi. The band is .025″ and the alternate set, aggressive hook teeth produce a kerf of about .044″, or slightly less than 3/64″.

Here’s the big deal about this blade: the teeth are carbide impregnated, which keeps them sharp vastly longer than those of conventional carbon or silicon steel blades. I have used this blade for years, feeding it thousands of feet of everything from dense exotic species to knotty construction lumber, and it remains quite serviceably sharp. Only that it is no longer as crazy sharp as it used to be, has me now wanting to replace it at the very reasonable price of about $31 for 143″.

Now, a 1/2″ blade may not suit much of your work, but it’s just what I need for the gradual curves characteristic of my work. Its nominal minimum circle diameter is 3 5/8″. What’s more, this blade resaws fast and true all the way up to the 12″ capacity of my saw – no blade changing needed. Virtually every project I make involves these two processes.

The hook teeth with this amount of set should not be expected to produce a surface ready for gluing laminates or thick veneer, but with a well-tuned bandsaw, the surfaces do not require a lot of clean up. I’ll go to other options if I really need an excellent surface directly off the saw.

All of the manufacturing details are excellent, including the weld, and especially the outstanding sharpness. Supercut Premium Gold blades also come in 1/4″ 6 tpi hook and 3/8″ 4 tpi hook.

The blades are made by a family-owned company in northern Idaho, the kind of small business I like to support. Supercut also makes an extensive line of other bandsaw blades and accessories. They will provide personal attention to your order on the phone.

As usual here, this review is unsolicited and uncompensated. I just really want you to use excellent tools made by good companies so you can make great stuff!

Category: Product reviews  | 6 Comments
Author:
• Wednesday, September 13th, 2017

woodworking skills

How would you reply if someone asked you, “Are you a good woodworker?” I think most of us seriously involved in the craft eventually ask ourselves this question. So, what might comprise a test of fundamental furniture making skills?

Here is what I suggest as a basic skill set for making furniture and accessories. It obviously does not encompass all of woodworking, nor does it include specialized techniques. As such it does not include skills, some of which you will eventually want to add, such as carving, turning, wood bending techniques, resawing, veneering, and finishing. And, of course, everyone will be able to cite exceptions and omissions.

The “test” recognizes that good work can be accomplished with both hand tools and machines, but also that principles of hand tool woodworking form a solid basis for learning and understanding the craft.

1 Wood:

  • Assess several boards of wood regarding grain orientation, defects, seasoning, and fitness for various uses.
  • Demonstrate an in-depth understanding of a few favorite species.

2 Stock preparation:

  • Using only hand tools, foursquare a rough 4/4 board, say 6-8″ wide by 18-24″ long to 3/4″ thick. The product should be sized to a snug fit between standards in length and width (fit by shooting).
  • Smooth the surface to an excellent appearance without applied finish.
  • Do another board with the aid of machinery.

3 Joinery: Make the following joints, demonstrating knowledge and skill in the critical aspects of joint design, strength, and appearance. You can use hand tools and machines, as long as the method does not reduce the quality of the outcome.

  • Use edge-to-edge joints to make a three-board panel, 12-18″ wide and 24-30″ long.
  • Make a three-shouldered blind mortise-and-tenon post-and-rail joint.
  • Make a through-dovetail joint with at least four tails.
  • Make a frame mortise-and-tenon joint of your choice.

4 Additional skills:

  • The tools for the test will be provided in good working condition but the “instructor” will randomly throw in a tool that will require minor tune up, so you will have to know how to assess all of them.
  • Starting with the factory grind, sharpen a 2″ plane blade according to its application (e.g. in a smoothing plane), a 1/2″ bench chisel, and a card scraper.
  • Layout, cut, fair, and smooth a reversing curve in 8/4 stock, 18-30″ long.

5 Basic constructions: All of the above skills are academic if you cannot integrate them to produce the fundamental constructions of woodworking. Again, you can use hand tools and machines, as long as the method does not reduce the quality of the outcome.

  • Build a dovetailed box/carcase in solid wood ­– just the four sides will do.
  • Build a post and rail frame – a “table” with straight legs and no top will do.
  • Build a frame-and-panel door.

These are just raw basic constructions but the results must be neat, flat, true, and square. You must demonstrate the ability to control tolerances. Within reason, the size of the constructions is up to you but the precision will be scrutinized commensurate with the size. (Hint: smaller is not necessarily easier.)

A few more things:

  • The test is timed only if you make money from woodworking; otherwise, within reason, it’s not.
  • You have to be able to design what you want to build, or at least be able to follow plans.
  • You can do the test in your mind if you want, but don’t cheat!
  • You automatically fail if you don’t enjoy every bit of it.

You’ve arrived.

Category: Techniques  | 3 Comments
Author:
• Tuesday, August 29th, 2017

Pat Warner

The passing of Pat Warner, July 28, 2017, should not go without tribute. His contributions to the techniques of woodworking is among the finest of our time based on his unsurpassed knowledge of the use of one of our most versatile woodworking tools, the router. He was truly an expert’s expert.

Especially remarkable were his profound insights into the precision tolerances involved in tooling and work processes, as well as his ability to manage them in the shop. His hands-on inventiveness produced an impressive array of precision tools and jigs. His writings, full of intelligence and clarity, include four books, numerous articles, and the resources on his website.

I never met the man but his generosity and kindness were evident in the assistance he provided to me by phone. There was no doubt I was taking in the advice of a rare master craftsman. For countless woodworkers, our approach to not only the use of the router, but to small-shop machine woodworking in general, owes greatly to Pat Warner.

Category: Ideas  | 7 Comments
Author:
• Friday, August 25th, 2017

mortise jig wedge clamps

In two earlier posts, I presented a router mortise jig. As writing is a good occasion to rethink matters, I have upgraded the clamping system on the jig. What’s more, this general design for a wedge clamp system can be applied to other shop jigs and fixtures to increase their holding range.

The mechanical advantage produced by the humble wedge is a wonderful earthly thing. I used larger blocks that rotate on an off-center pivot to accommodate a much greater range of workpiece width. The plywood base of the jig is also wider than the original to allow for this, and thicker at 3/4″ for greater strength. The blocks and wedges are 5/8″ thick.

Each block is 2 1/2″ square. The center of the pivot hole is 1/2″ from one edge, and 1″, 1 1/2″, and 2″ from the three other edges. Thus, there are four different rotational positions to create a large range of clamping width capacity.

Below, the block is in position to clamp the widest workpieces.

wedge clamps

The wedge is 8 ¼” long with a 1:7 slope. This produces slightly more than 1/2″ range of clamping width, which spans the difference from one block position to the next.

Below, the block is in position for the second-to-narrowest clamping capacity.

wedge clamps

A 1/4-20 x 1 1/2″ hex bolt, unthreaded in the 5/8″ nearest its head, enters from the bottom of the base with the head recessed in a counterbore. It is secured above the block with a nylon-insert lock nut, which is tightened to allow free but firm rotation of the block.

The wedge clamps work so well that they may obviate the need for the toggle clamps. The wedge system particularly makes the jig better for mortising frame members. Because these are narrower than leg blanks, they are best clamped in a pair to increase the seating width for the base of the router jig.

Author:
• Wednesday, August 23rd, 2017

DeWalt XL trigger clamp

Of all the squeezy clamps that I have tried out in a store or used in the shop, this is the first one that I can reach for with confidence.

The tightening handle is big and comfortable, making it pleasant to apply the rated 600 pounds of force. The bar is a sturdy I beam. The release trigger is readily accessible and has a nice curve onto which I can hook my finger, making it easy to release the clamp pressure. And my fingers do not get bumped in the process. Most of the other clamps of this type that I have tried out have an annoyingly uncomfortable release.

What I like most are the large rectangular pads, which are almost like those of a parallel bar clamp. The throat depth is about 3 3/4″. The pad material is just right – soft enough to protect the work but not squishy. The fixed jaw can be easily reversed to use the clamp as a spreader.

Squeezy clamps are wonderfully handy for bench work, but have a tendency to shift the workpiece alignment when used for assembly. This is inevitable if you squeeze down the force in one fell swoop.

I suggest the following technique to avoid workpiece shifting. Gradually pump in the jaw contact while maintaining the workpiece alignment with the other hand, readjusting it if necessary. As you take up the toe-in of the jaws (which is mostly in the moveable jaw) and build just a little bit of pressure, the clamp itself will stabilize. This is the key moment because then, and only then, can you bull down the force and the workpiece will remain stable. I usually find it best to hold the fixed jaw against the workpiece and advance the moveable jaw into contact.

You can find them at the orange palace and elsewhere.

This review is unsolicited and uncompensated.