Author:
• Sunday, January 31st, 2016

wood finishes

Good job! You developed a compelling design, skillfully employed sound construction techniques, and lavished care on your baby – I mean woodworking project. And of course, you applied a finish that made her look fabulous when she – uh, it – left the shop.

Well, it’s not over because it’s a jungle out there. Consider especially that pretty finish in which you sent your furniture/accessory oeuvre out into the world.

Think about the likely use and possible abuse of the piece. Sure, a wall cabinet for art objects will not suffer as will a dining table, but will that hall table display family photos or have keys and wet umbrellas tossed onto it? Will later owners of the piece value it as much as the original owner?

A key issue is that the durability and reparability of a wood finish are generally inversely related. For example, oil-varnish mix is not very durable but is easy to repair, while a tough polyurethane film finish is more difficult to repair.

I think in many cases it comes down to which is more tolerable: dented, scarred wood or a dented, scarred thick film finish. Ultimately, water, abrasion, and ultraviolet light can break down any finish, resulting in something like the table top below. When dirt and grime get into the grain of the wood, restoration gets even more difficult.

deteriorated finish

One approach, which is gaining appeal with me in some cases, is to take it easy and apply a few coats of oil-varnish mix. I like Rockler’s Sam Maloof poly-oil because of its high solids content and amber color that is not too dark like some oil or varnish products such as Waterlox. It leaves a low-key sheen that allows one to “take pleasure in the wood surface,” as the late, great Sam said.

The car key abrasions probably will look better – and maybe even add character – in a wood surface finished with oil-varnish mix that can be easily touched up by anyone, than in the layers of a heavy film finish that will probably never be repaired by anyone.

There are always trade-offs. The point is to think it through the long term when choosing a finish.

walnut finish

Category: Techniques  | 3 Comments
Author:
• Saturday, January 30th, 2016

Corradi rasps

These Corradi rasps are the ones I reach for most often. Several years ago, I wrote on choosing and using rasps, highlighting the excellence of hand-cut rasps, specifically the Auriou brand, based on the feel and feedback they provide.

In this regard, for a 10″ cabinet rasp in the finest grain, I still prefer the Auriou #13. However, I’ve come to prefer the Corradi rasps in the coarse and medium ranges. Furthermore, I don’t think there is a big difference between the finest Corradi #10 and its close equivalent, the Auriou #13. Practically, I tend to save the Auriou for the most sensitive work, much like a carefully tuned smoothing plane.

The Corradi rasps have uniform, densely packed, machine-cut teeth with a surface hardness of Rc 65-66, which the manufacturer claims is harder than the best hand-cut rasps at Rc 59-60. In my experience, which is not controlled testing, the Corradi rasps have indeed maintained their sharpness better than the Aurious.

The swirl pattern of the teeth produces a very smooth cutting action, though again, just slightly lacking the superb feedback of the Auriou in the finest grain models. In the medium and coarse grains, I prefer the consistent smoothness of the Corradis. I do, however, wish the Corradi cabinet rasps were shaped to a point like the Aurious.

Heresy, some may say, but I’m only telling you what the wood and my hands have told me. These comments, unsolicited and uncompensated, are only meant to help readers make their own choices.

Corradi 5, 8, 10 grain

My set of Corradi 10″ half-round cabinet rasps consists of the “Gold” #10 and #8, and the Cabinet #5, from right to left in the photo above. This set is an excellent value at a current total price of $134. By comparison, a single 10″ half-round Auriou #9 costs from $110 – $135, and the finer grains cost still more.

For reference, in 10″ rasps, I estimate the Corradi #10 about the equivalent of the Auriou #13, though the latter is probably a trace finer. Either allows a very easy transition to scraping or sanding.

At the coarse end, the Corradi #5 is about equivalent to an old Nicholson #49 (below, at left and right, respectively), but broader and better. (The Auriou #9 approximates a Nicholson #50.) Looking at the photo above, it seems like a fairly large jump from the Corradi #5 to the #8 but in practice the transition works well.

Corradi 5 grain vs Nicholson #49

The three 10″ half-round Corradis – #5, 8, and 10 – plus an inexpensive Shinto double-sided “saw” rasp and a cheap Surform Shaver, with the modification described in an earlier post, form a versatile basic set. I wish Corradi made “ironing” rasps in the form I described in a recent post.

Aside from cabinet rasps, I like the Corradi Gold 6″ #10 flat (“hand”) rasp with one safe edge for smaller scale work such as rounding over tenons. The 4″ Auriou half-round #14 remains the finest rasp in my drawer.

Rasps are often underestimated but high quality versions, skillfully employed, are capable of sensitive, refined work.

Category: Tools and Shop  | 2 Comments
Author:
• Monday, January 25th, 2016

reference constructions

When designing and making a particular joint or subassembly, an actual sample of it is a great aid to spatial thinking. I keep a bunch of these brain helpers in the shop, including various mortise and tenon configurations, sliding dovetails, a section of a web frame, some curved legs, and, of course, a drawer or two. Most are unglued to permit study.

In the design phase of a project, when considering proportions, thicknesses, and surface relationships, the models help in a way that drawings cannot. Later, they are useful when strategizing construction methods. They are particularly helpful if it’s been a while since I last incorporated such an assembly into a piece.

A reference model does not have to be very neat or even complete. Most likely it will be one section of an assembly or the critical parts that are just enough to direct your thinking. I often write notes and dimensions on the reference models, especially if there’s something that I’m not likely to notice later. Basically, give yourself all the help you can; woodworking is hard enough already.

Accumulate the models from practice joints, experiments, or extras from a past project. It’s amazing how some in my shop of have aged and then jog my memory when needed. “Oh, that’s how that frame went together,” or whatever, in some project from the past. A piece that you completed long ago may be unavailable to you now but even if it is, you can’t disassemble it.

Since virtually all of my woodwork is one-of-a-kind, the reference models serve as brain assistants, not formulas. I benefit from my former efforts but I’m still thinking things through as they pertain to the project at hand. I really enjoy that combination!

If accumulating reference constructions is not a woodworking habit of yours, consider giving it a try. I think you’ll find it pays off.

Author:
• Thursday, December 31st, 2015

square to check dovetails

When making dovetail joints, it is important that the tails, which you’ve cut first (of course, right?), have their sides square to the reference (inside) face of the board.

In practice, depending on the compressibility of the wood species being worked, it may be acceptable or even helpful for the inside width of the tail to be a hair narrower than the outside face. This creates a slight wedge effect that helps ensure tightly meeting surfaces at the outside face of the completed joint.

There should never be the opposite arrangement where the entering width of the tail is wider than the outside face of the tail. That would directly, by the geometry of it, leave gaps on the show face of the joint, making it weaker and less attractive. It would also indirectly create these gaps by corrupting the marking out of the pins from the inside-face edges of the tails.

Thus, as with many aspects of woodworking, this is a one-sided tolerance issue, and we want to avoid compounding small errors.

So, is it really necessary to check the sawn surfaces of the tails before proceeding to mark and saw the pins?

With good sawing skills, frequent repetition, and an easy-going wood, you may need little or no checking. Realistically however, it is not easy to make all the saw cuts right on, and checking takes very little time and effort. And while you or a demonstrator may be heroic in pine, what about oak, shedua, or hard maple? Also, it’s a lot easier to dovetail a 3/8″-thick, 3″-wide drawer side than a 3/4″-thick 12″ carcase side.

I suggest be realistic and reasonably careful in your work without being timid or plodding.

dovetail square

Here is the little square I use to check the sawn sides of the tails as well as the adjustments I make by paring them. I made this tool about 30 years ago.

The beam, made of pre-ban Brazilian rosewood (Dalbergia nigra), is about 4 1/4″ long x 3/4″ x 1/2″. The 1/16″-thick brass blade is 11/64″ wide, which can fit between almost any pair of tails that I make. At almost 1 3/4″, it is unnecessarily long – maybe I envisioned sometime making giant dovetails. The square is accurate to less than 0.001″ on both sides, a tolerance not too difficult to achieve in this size tool with patient filing and scraping.

The T shape allows the beam to register on the face of the wood on both sides of the measurement point. This makes it fast and convenient to use. It also averages out any trace of cupping that might have creeped into the board since it was four-squared.

There are two excellent manufactured tools for this task. One is the little (in size but not in price) Starrett 14D square, shown below, which has a blade 5/32″-wide over most of its length that is cut down to a mere 3/32″ wide over the remainder.

small squares

A lot less expensive is Sterling Toolworks’ Dovetailing Rule. This blade fits in a 6″ combination square stock (Starrett and others) and has a section just under 3/32″ wide to fit between virtually any pair of tails. Chris Kuehn, founder of Sterling, has produced a practical, commercially available solution.

Author:
• Friday, December 18th, 2015

woodworking tools

It has been a while since I expanded this wish list, so here goes.

1. Is it too much to ask for Lee, Lie, or some other great maker to come up with a modern compass plane? To use this tool effectively, think of the compass plane as a light jack plane, not a smoother, for curves. As with other hand planes, I have little doubt that modern manufacturing, informed by history, will outdo vintage models.

2. Speaking of tools for curves, a curved rasp, flat across its width, would be nice. Start with the idea of the “curved ironing rasps” made by Auriou (pictured above) and Liogier but make one about 6-7″ long, 1 1/2″ wide, with a knob on the leading end and a near-vertical handle at the rear. And Santa, if you’re listening, I want the radius of the curve to be smaller toward the rear and larger toward the front. Medium and fine grain, thanks.

None of the following currently available tools quite fits the bill: flexible floats, the very coarse Liogier Beast, and the Surform shaver. The latter is decent when modified, but it’s rather short.

3. The Pony brand 22″ hard-tooth saw with three-bevel, Japanese-like teeth is a wonderfully useful stock breakdown tool and a great value at about $16. It crosscuts like a demon but does not rip very well. A 26″ rip tooth version would be a very useful bargain.

Pony hand saw

4. I still haven’t given up on advocating a higher bed angle for bevel-up bench planes. About 22.5° would be good. This is a large topic that has been addressed earlier on this site but here are some highlights. [I should add here that this is mostly applicable to bevel-up smoothing planes.]

Compared to a 22.5° bed, the 12° bed angle in Lee and Lie bevel-up models may have a slight advantage in reducing the downward deflection of the blade edge but I think this is made largely moot by the excellent support of the blade close to its edge that is provided by the bevel-up design.

The 12° bed creates problems with sharpening. For example, to get a 55° attack angle, the blade must be sharpened to a 42.5° secondary bevel. That makes it significantly more difficult to produce and retain a good edge.

Even if you don’t agree with my contention that such a blade creates a fatter wedge that is more difficult to drive through the wood, and that the only thing the woods “sees” is the attack angle, then why not use a 22.5° bed and make edge creation and retention easier?

5. To mark pins from tails, in some situations, I prefer to use a chip carving knife like this, modified to eliminate the secondary bevel. I learned this idea from Chris Becksvoort.

However, it is not easy to flatten both sides of the blade to meet at the edge in a single bevel because the angle gets quite small, making the edge fragile. It would be nice to have a manufactured version. The sides of a blade 5/16″ wide and 1/8″ thick at the back would meet in a single bevel at 25°.

6. I wish the pads on my earmuffs did not squeeze the temples of my glasses against my skull. It’s uncomfortable. And I hate earplugs.

7. When jointing and planing to get flat stock, the thickness of some boards seems to disappear faster than cash in my wallet. I don’t need a board stretcher, I need a board inflator.

Hope is a good thing.

Category: Tools and Shop  | 8 Comments
Author:
• Thursday, December 03rd, 2015

furniture books

One of the best ways to develop your design skills is to look thoughtfully at lots of furniture, including unfamiliar work. Books and collections that organize work in historical and stylistic context are especially helpful learning tools. Here are two books that are both worthwhile but differ greatly in approach.

Furniture by Judith Miller (Dorling Kindersley Publishing) covers furniture design from ancient Egypt to contemporary. [Note: At Amazon, the larger format 2005 American edition is now much more expensive than the slightly smaller format 2010 UK edition.]

Done in the beautiful and orderly style typical of DK Publishing, the more than 500 pages will supply you with plenty of browsing hours. It is organized primarily by time period, for example 1760-1800, then by country and style, for example late 18th century Scandinavian. I like best the several sections within each time period that are devoted to specific furniture types, which allow you to study, for example, tables in the Art Deco period of 1919-1940.

Even though anything I design and make is unlikely to directly emulate more than a few, if any, of the pieces in this book, there are lots of stimulating ideas, motifs to borrow, and much to learn just from studying a wide variety of good design.

That’s the good part of the book. Now for the bad and the ugly. It is painful enough just to look at much of the furniture in the “Postmodern and Contemporary – 1970 Onward” chapter, but it is exacerbated by reading the highbrow credibility given by the author to some of this crap.

There is no Maloof rocker or Krenov cabinet to found here, though we are informed that Castle, Maloof, and Frid “worked in a highly contrived Postmodern style.” Further, the author states, “Using a laborious, painstaking method to produce off-hand, jokey objects was self-consciously ironic.”

Administer relief to yourself from such nonsense by picking up Craft Furniture by Dennis Blankemeyer (Schiffer Publishing, 2003). The author does an outstanding job of placing this work in the context of our daily lives and, more broadly, in our spiritual lives. He also gives fitting tribute to craftsmanship.

After sections on Esherick, Krenov, Maloof, and Nakashima, he presents the work and background of 25 contemporary craftspeople. There is so much beautiful, honest woodwork here; I think readers are sure to find it inspirational.

I suspect this book has not gotten the attention that it deserves. It is available in only hardcover from Amazon and Barnes and Noble.

Resolving the different vantage points of these two authors is a matter for another day. I’d rather get back to the shop.

Category: Resources  | 4 Comments
Author:
• Sunday, November 29th, 2015

wood information resources

A good woodworker must know a lot about wood. Unlike glass, clay, and metal, wood is a product of biology and so, wonderfully, comes to us in incredible variety. No project is likely to be successful unless the properties of the species and even the particular boards at hand are taken into account.

To that end, here is a compendium of the best resources, in this writer’s view, for woodworkers to increase their practical knowledge of wood.

Top two books

An easy choice for the premier book is the venerable Understanding Wood by R. Bruce Hoadley. First published in 1980 and revised in 2000, this is the book every woodworker needs to understand wood anatomy, strength, dimensional changes related to moisture content, drying wood, and much more.

For information on specific species along with color photographs, plus a concise exposition of basic wood concepts, the newly published Wood! by Eric Meier is the best choice available. It has major entries for about 250 species plus about 100 more covered in tables and lists. This book rises above several other similar attempts in that it is truly directed at the hands-on woodworker.

Not to be forgotten

In the same vein but with greater depth are 22 incomparable articles written by the late Jon Arno for Fine Woodworking magazine. Covered are: ashes, basswood, beech, birches, catalpa, cherry (two articles), chestnut, hickory and pecan, ipe, mahogany, maples, oaks, orchard woods, pine, poplars, sassafras, sweetgum, sycamore, and walnut, plus articles on health risks associated with wood and wood identification. Go to the Fine Woodworking website and search Jon Arno. You can get full access to everything in the site (and download PDFs of articles) for reasonable fees.

Four more books

The Wood Handbook (sometimes titled in print as the Encyclopedia of Wood), published by the US Forest Products Laboratory, has a wealth of technical information on all wood matters. Best used as a reference, there is no reason not to have this book: it is available as a free download from the FPL site. It is also available in print.

With the Grain: A Craftsman’s Guide to Understanding Wood, by Christian Becksvoort, published in a low-key but appealing style by the Lost Art Press, is a very good, very readable option to get just about all the basic information in concise form from a great woodworker who really knows wood. Highly recommended.

Wood: Identification & Use, by Terry Porter, is a beautiful, very worthwhile collection of photos and information on more than 200 species with an additional 200 briefly listed. Though I find it more attractively produced than Wood!, it lacks the latter’s outstanding practical utility.

Getting the Most From Your Wood Buying Bucks, from American Woodworker, is less broad in scope but is included here for its excellent practical articles.

Online

Forest Products Laboratory’s Tech Sheets (see lower right of linked page) give detailed information on many domestic and exotic species.

The Wood Database, by the author of Wood!, should be bookmarked by all woodworkers. Go there and you’ll see what I mean; it’s invaluable.

For true-to-life photos of wood, numbering approximately one zillion, Hobbit House has no equal. This is a great reference to see the different looks within a single species of wood.

A series of monographs on domestic species by Purdue University professor Daniel L. Cassens is available as free downloads (page down the linked page to the species list). These articles also have the flavor of being written by a guy with sawdust in his pockets.

Two more things

With all this knowledge of wood, one of the most useful ways to put it to use in the shop is with Lee Valley’s Wood Movement Reference Guide. This handy wheel chart allows you to easily compute wood movement for different species through a specified range of humidity. Well worth the $9.95, I use it all the time.

When you’re looking for wood (and when are you not, if you love the stuff like I do), the Wood Finder site can widen your world of sources.

Some much wood, so little time . . .

Category: Resources  | Leave a Comment
Author:
• Sunday, November 29th, 2015

power tool safety

Here is a palpable way to look at power tool safety.

This occurred to me as I was holding in my hand the DeWalt DWP611 compact router. It is so easy to wield this little machine with one hand – it’s easier to grip than a youth-size football – that I sensed a bit of over-confidence sneaking in as I was preparing to put it to the wood.

This little beast, however, has a tail that plugs into an electrical outlet, so it can generate 1.25 HP. Question: are you more powerful than a horse?

Moving over to the table saw, here’s another question. The tip speed of a 10″ blade at 3450 RPM is 103 MPH. Think about kickback. Are you faster than that?

There is no way the woodworker is strong or fast enough to beat an out-of-control power tool. Therefore, the operation to be performed must be fully controlled and fully predictable. There is no room for doubt or hoping. You must know what is going to happen before it happens.

It is difficult to over-emphasize: we ultimately must control our power tools with our brains. Knowledge, proper setup, patience, and alertness are absolute requirements.

Without them, we’re just not good enough.

Category: Techniques  | 5 Comments
Author:
• Wednesday, November 11th, 2015

Wood! book

Eric Meier, the creator of the superb online resource, The Wood Database, has a produced a new, wonderfully useful book for woodworkers: Wood!, subtitled “identifying and using hundreds of woods worldwide.”

If you are not already familiar with the Wood Database, I urge you to visit the site and bookmark it because you will return often, as I do. In fact, you may find it hard to leave this magnificent collection of practical information and data on hundreds of species of wood accompanied by high quality images of each.

It is not an armchair xylophile’s catalog but rather a go-to resource for people who not only love wood but also love cutting it into pieces and making stuff from it. In addition to the species information, there are many insightful articles that reflect Eric’s deep, hands-on understanding of wood.

Now to the book. Eric’s goal was to make a book that would serve the real needs of woodworkers. He has succeeded impressively. In its highly accessible combination of wood science with practical, reliable information and images for hundreds of wood species that is directly usable by woodworkers, I believe this book is unique.

The first five chapters concisely cover wood basics, wood and moisture, identifying wood, and softwood and hardwood anatomy. Whether as new material or for review and reference, this is core information that will make you a better woodworker. It is presented clearly and intelligently.

The heart of the book is information, data, and images of about 250 wood species, designed to help woodworkers knowledgeably work wood. Among the data included are hardness, strength, and shrinkage properties. The consistently derived density values are the most useful I have seen. Having worked more than 50 of the species listed, I can attest to the remarkable veracity of the author’s comments on the workability of these species.

There are also helpful tables on groups of similar woods, such the oaks, maples, and ashes. The species are wisely listed alphabetically by genus but the index effectively cross-references common names. As minor criticisms, many of the photos are a bit dark to my eye though they still give a good sense of the real appearance of the woods. The book is attractive and very easy to navigate but I would differ on some of the layout aesthetics.

Wood!, the book, is very similar to the Wood Database website, so you might wonder if it’s worth buying. Yes! It is very much worth it, in my opinion. You can joyfully browse the book as you conjure your next project in a way that roaming a website cannot match. Moreover, the book is just an outright joy that you’ll have trouble putting down. And I really like the dedication page.

[Disclaimer: This review is unsolicited and uncompensated, nor have I played any role in the production of the book or website.]

Category: Resources  | 4 Comments
Author:
• Saturday, October 10th, 2015

mortise and tenon

In building furniture, woodworkers wonder if the joints will be strong enough to withstand the many years of rigors to which they will be subjected.

As we parse the elements of joint design, figuring if a tenon is long enough, dovetails deep enough, and so forth, we rely upon hundreds of years of cumulative experience in furniture design and observation of how pieces have fared over the years. We also can benefit from some of the joint testing done by the magazines, data from the Forest Products Laboratory, and of course, a healthy dose of intuition.

However, there is a shortcoming in viewing joint design too narrowly.

Assuming competent joinery skills, answers to structural strength questions are more likely to come from broadening one’s view beyond the joint under consideration and looking at the whole structure of the piece. This will make the requirements for a particular joint more evident.

Here we must ask:

  • What is going on in the overall design of the piece that will transfer stress to that joint, and on the other hand, help it to resist stress?
  • How will normal use, and perhaps abuse, stress the joint?

table design

For example, this table has fairly narrow legs that allow only shallow mortise and tenon joints. Force applied to the lower part of a leg produces considerable moment at the joints. Racking in the horizontal plane could also be a problem.

However, looking beyond the leg joints shows they have plenty of help. The two cross stretchers are joined to the aprons with sliding dovetails, and there is a corner block behind each pair of leg joints.

table design

As another example, in a bookcase, the joints attaching the horizontal to the vertical members are subject to huge racking forces. Yet, a thin plywood back fastened to the back changes everything.

The point is that when designing furniture and wondering if a particular joint will be strong enough, let the big picture inform your engineering decisions.

Category: Techniques  | Leave a Comment