Tuesday, July 26, 2011

Skin deep

In the Charles Dickens' novel Our Mutual Friend, we are introduced to the Veneerings, Hamilton and Anastasia:

"Mr and Mrs Veneering were bran-new people in a bran-new house in a bran-new quarter of London. Everything about the Veneerings was spick and span new. All their furniture was new, all their friends were new, all their servants were new, their plate was new, their carriage was new, their harness was new, their horses were new, their pictures were new, they themselves were new, they were as newly married as was lawfully compatible with their having a bran-new baby, and if they had set up a great-grandfather, he would have come home in matting from the Pantechnicon, without a scratch upon him, French polished to the crown of his head.
For, in the Veneering establishment, from the hall-chairs with the new coat of arms, to the grand pianoforte with the new action, and upstairs again to the new fire-escape, all things were in a state of high varnish and polish. And what was observable in the furniture, was observable in the Veneerings--the surface smelt a little too much of the workshop and was a trifle sticky."

Hamilton Veneering is further described elsewhere in the novel as "forty, wavy-haired, dark, tending to corpulence, sly, mysterious, filmy—a kind of sufficiently well-looking veiled-prophet, not prophesying". Mrs Veneering was "fair, aquiline-nosed and fingered, not so much light hair as she might have, gorgeous in raiment and jewels, enthusiastic, propitiatory, conscious that a corner of her husband’s veil is over herself."

Forever holding dinner parties in an attempt to win the 'right' sort of friends in the 'correct' sort of social circles, Veneering gets himself elected as the MP for to town of Pocket-Breaches. In the end, however, he makes a ‘resounding smash’ (i.e., he is financially ruined). The Veneerings consequently "retire to Calais, there to live on Mrs Veneering’s diamonds". Society then discovers that it had always despised and distrusted the Veneerings.

Indeed, Dicken's portrayal of the Veneering's led to the expression in the late 1800's, noted in E.C. Brewer's The Readers Handbook of Allusions, References, Plots and Stories, the "veneering of society": flashy, rich merchants, who delight to overpower their guests with the splendor of their furniture, the provisions of their tables, and the jewels of their wives and daughters. Social climbers, show offs, wannabees.

I want to talk about a more literal sort of veneer work in today's post: veneered furniture, which has been around a while and become a very common form of construction. Like the Veneerings, veneer historically has not had the best of reputations, and indeed one of the dictionary definitions of the word is:

"Superficially valuable or pleasing appearance."

Synonyms listed for veneer include: façade, front, show, mask, guise.

In a 2010 issue (October, #185) of Popular Woodworking, an author named Marc Adams wrote a piece called Veneer is the Future, Part I. I don't know this author personally, however I understand he operates a business as a woodworking school, and has been practicing veneering for many years. I, on the other hand, must speak about veneering from a distance, having only observed the practice, and the resultant products, both old and new, for many years and having thereby formed definite opinions about veneered work. So my opinions are not from the vantage point of a battle-scarred veteran of the veneer wars, but I hope they will be worth something all the same.

The part I article deals with the reasons which Adam feels justify the use of veneer, while part II (found in the following issue, #186) deals with the 'how' of veneering.  I suggest readers who have not had a chance to read the part I article do so by clicking the provided link before continuing on with my commentary. You see, while I respect the author's opinions, I have a diametrically-opposed view on veneer, and I would like to take the opportunity here, for whatever it is worth, to serve up a few counterpoints to the opinions brought forth in the above-cited articles.

Looking through Adam's part I article, after acknowledging the bad press veneer has had, he goes on to make a strong argument for its use today. One of the first reasons he gives for this is that,

"...technology has improved. Core materials have improved tremendously, including the introduction of MDF. Space-age glues and vacuum technology have simplified the pressing process".

He's absolutely right, though I'm not so sure that plywood, a common substrate upon which veneer is glued, has improved. While plywood is indeed a wonder material in many respects, with some outstanding qualities (I use it to make storage boxes for my portable power tools), today's plywoods are getting cheaper and lower in quality than they used to be, with fewer laminae, from what I have observed. 'Good' plywood, when you can obtain it, is certainly not cheap. And MDF , essentially ground up sawdust bound together in a sheet with adhesives, is a very flat and uniform material - ideal, I would say, for making woodworking jigs. But not furniture. It has poor strength and if is gets damp, a disaster unfolds.
Here's the thing-  when you get down to what veneered furniture actually IS, you are faced with the essential point that it IS just a decorated plywood box. Or, quite commonly, it IS a decorated particle board box. In either case, all you have are decorated boxes fastened together with glue, staples, dowels, and/or compressed fiber biscuits. The veneer itself is akin to paint on the surface, and indeed, most people who do veneer work, or design veneered pieces,  more or less treat the veneer as if it were paint, giving no regard to a logical - natural, I mean - orientation of wood grain. So veneer is imitating wood in the most superficial manner, and veneering as such represents a bit of a diversion away from working in harmony and understanding of a natural material and into the charade which is characteristic of the interior decorating mindset. It's all about the surface of things, and subject to fashion changes. More on those fashion changes in the next post. Also, the diversion away from how wood naturally works means a move to control and predictability - both of which suit industrial production very well. More to come on that point too.

Adams notes that 'correctly balanced' veneered plywood panels is "far stronger than solid wood of the same thickness." This is true, but only in a limited sense, and depends upon how one defines strength.  Solid wood is anisotropic, having different degrees of strength relative to the direction of load in respect to the run of the grain.

In a piece of plywood, each laminae has the grain running crosswise to the layer above and below it. In order to keep the plywood stable, there are typically an uneven number of layer of layers, so that the outermost layers both have grain running the same direction. In short, a little less than half of the layers in a sheet of ply are running crosswise to the layer one sees on the faces. This means that plywood is stiffer in resistance to bending in one direction than another. And when compared to a piece of solid wood of the same species (typically, that is, a softwood) as found in the plywood sheet, one can see that all of the grain in the stick of wood will be running the same direction. If one measures strength then by resistance to bending, a rather important matter in most furniture construction, then solid wood is a better and stronger choice. In short, plywood is not often a good choice to resist bending because the plies with cross grain contribute almost nothing to resist the bending load that a shelf, say, must withstand. Plywood bookshelves are ubiquitous these days, and over time they tend to sag - possibly this is due to creep in the adhesive. Certainly, plywood is not an ideal choice for that application, but it is cheap.

Plywood is very strong in other respects compared to solid wood, like shear parallel or perpendicular to 'grain' direction of loading, but I would say that those issues are generally minor concerns in furniture. Resistance to bending is much more important.

There's an online calculator (<-- link) available for determining the sag of various shelving materials, and I invite you to take a gander. Comparing apples to apples, I input data for a 3/4" Fir Plywood shelf, 36" long and 10" wide, with either a balanced load or an unbalanced load, and compared the resulting deflection to solid 3/4" Douglas Fir (coastal) - the plywood deflection was 50% greater than the solid wood. A common way to stiffen up a plywood shelf? Adding a solid wood edging.

More to the point though is that if I wanted to build a stiffer shelf, in plywood I am left with laminating more plywood layers together, to build up, say, a 1.5" thick shelf from two 3/4" sheets, or constructing a torsion box arrangement using thinner plywood; both are solutions which result in a thick wooden shelf and that takes away from the available storage space in the unit and suffers an aesthetic penalty in many instances. Of course, I could also apply metal angle iron reinforcement and so forth as well, but that is a proof positive that plywood is insufficient to the task. In solid wood, if I need stiffer shelves I simply move to a species which is inherently stiffer, like Oak, Maple, Goncalo Alves, Purpleheart, etc..

Sag is of course an issue with solid wood as well. I have an inexpensive bookcase (on loan from my mother in law) in my living room about 36" wide made of 3/4" Pine, and the shelves sag slightly from the books. Pine shelves and a 36" span do not combine especially well - if it were 18" or 24" wide, then things would probably be fine. When I made myself a bookcase, 30" wide, I made the shelves out of cherry and there is zero sag when loaded with books. With plywood you don't have that option of changing materials (though there are pricey 'aircraft' plywoods which are stiffer), as the interior constituents of plywood are often not especially different from one another. You can get more layers or fewer, but all of the layers are still generally a softwood - or worse. One cannot readily obtain, say, 3/4" plywood in which any/all the interior laminae are composed of a stiffer wood, like Maple or Oak. When you buy 'oak' or 'maple' plywood, the only place the oak or maple is found is on the wafer thin exterior faces. It's really a softwood ply.

Now of course, while I can readily switch from a fir/pine bookshelf to a bookshelf made from a stiffer wood, there is often a price penalty to be incurred for that. But at least you know what you're getting. With the veneered plywood shelf, one could pay vastly greater sums for having East Indian Rosewood veneered shelves, but underneath it all, you still have the same fundamental reality - it's a plywood shelf. It's not going to perform significantly better than the fir-faced plywood shelf.

Adams asserts in his article, in a section entitled, Why Veneer Survives - and Thrives,  that veneers are,

"...as a material, green by design - it's durable, renewable, and sustainable."

I was somewhat astonished to read that, however I thought I would read on to see how he comes to this conclusion. Well, he doesn't really back those statements up, however I can surmise that a part of this boils down to the apparent economics - you get more yield of veneer from a given stick of wood, in terms of square footage that can be covered, than you do when sawing boards out of that same log. The argument for economy in other words. Economy of materials is 'efficient' and leads to a less expensive product while multiplying the profit ($$$) one can obtain from a given log. Perhaps that best explains why veneer thrives these days, the good old profit motive?

There's a slight problem though with the economy argument however, and a problem which directly affects the 'green' picture and the 'sustainability' of veneer. I'll look that matter in the next post.

Thanks for dropping by the Carpentry Way today.

Wednesday, July 20, 2011

Coffee Anyone? (17)

Post 17 in a series describing the design and construction of a coffee table, with previous installments to be found in the blog archive to the right of the page.

In the last post, I completed the work to join the table top frame members together. Next up, I had a few loose ends, joinery-wise, to attend to.  The draw bars which connect the legs to the table shelf frame needed to be fitted up. I sized them so that they were a mild interference fit in the leg mortises. With the bar driven in with the aid of a mallet, I used the hollow chisel mortiser to prepare the fixing pin mortises:


A short while later, all four legs were fitted with their draw bars and mortised for the pins:


The next item on the 'tick list' was to trim the draw bars to final length. I decided to modify a jig i made previously so as to allow the legs to be fixed identically and run through the table saw:


Here are the four legs after the table saw work is complete and the draw bars shortened:


I then fitted the leg and its draw bar up to the shelf frame pieces:


A clamp ensured that the joint was fully closed up:


Then I used a hollow chisel mortise bit to mark the draw bar:


 I separated the pieces, then set up a small kama-kebiki to mark the mortise lines on the draw bar, bringing the lines in 1/32" or so from the mark left by the hollow chisel bit in the previous step. This allows for a draw-bore effect:


Some mortising took place after that, using a small drill bit to punch out the hole, and then a chisel to clean up the mortise:


 The pin mortises have slightly less relish on them than I would prefer, however I believe they will be fine considering the hardness of the material and loading conditions on the joints being not especially high. To obtain the ideal amount of relish, I would have had to widen the shelf frame pieces by at least 1/16" (1mm). Next time.

Mortising work complete, I then drove the fixing pins, komi-sen, into position:


Pin after it has been driven in:


Next, I trimmed the pins flush with the surrounding surface and cleaned off using a pass with a paring chisel:


That pretty much wrapped up the joinery work, once all four legs were similarly complete.

I then commenced the finishing work, which involved a fair amount of chisel work on the leg 'stirrups':



Then it was a matter of more chiseling, then some scraping, filing, and sanding, over and over again, to complete the legs. I didn't take any photos.

It was at last time to apply oil, round 1:


Here's my drying rack:



My apologies for the blurry pictures - the studio photos I'll get done next week will hopefully make up for it.


And round 3 of oiling for the Wenge shelf panel:


I experimented with using the Whey based finish, but I decided I preferred the darkening imparted by the Tung oil to the bubinga, so I'm sticking with Waterlox for this project. Otherwise, the whey-based finishes were fine, no VOC's and easy to apply, rapid drying, etc., and the next project I do involving a lighter wood, like oak, say, I will likely go with them.

All for today, thanks for coming by.  --> on to post 18

Saturday, July 16, 2011

Coffee Anyone? (16)

Post 16 in a series, with previous installments archived to the right of the page. Other topics and other build threads can be accessed through the labels index, also at the right of the page.

Last time, I left off at the point at which the draw bars and their associated mortises had been prepared:


Next on my rapidly dwindling list of tasks to complete were the shachi sen, tapered wedging pins. I prepared some slightly oversize stock for the pins, chopped the pieces to length, and then used a simple jig in my router table with a dovetail bit to process the pins into a parallelogram shape:


Then it was a matter of fitting the pins one by one, to their trenches, shachi-mizo. Here, I've fitted two pins to one side and am reassembling the connection:


Back together:


In goes a third pin:


And a fourth:


Another view:


The pins are not fully fitted yet - my purpose here is to fit them sufficiently so that the joint could be tightened up and I could work on completing the shaping of the re-entrant corners, which had been left with extra material on them during the CNC stage to prevent tear-out by the cutter.

It just so happens that another woodworker in the building bought a used oscillating spindle sander a couple of weeks back. He cleaned it up and re-painted it, in what I must say was perfect timing in regards to my project needs. That sander looked like a good way to deal with shaping these re-entrant corners, a detail I frequently incorporate. In the past I've used a combination of rasps, files, gouges, scrapers and dragging a piece of sandpaper around a metal pipe to work these areas.

Let's have a go with the oscillating spindle sander, a Grizzly product:


Another view:


 I gotta admit, that worked really well. No tear out, and a decently smooth finish. A minor amount of scraping and it will be done:


Here's a look at the topside


Jeez, have I slipped over to the dark side? I now need to get one of those spindle sanders - definitely the best tool for that particular job. Come to think of it, it was an oscillating spindle sander that I witnessed in use shaping bracket blocks at Kongo Gumi, a temple building construction firm I visited in Ōsaka years back. Now I feel a little better.

In time, I had all four corners done, and assembled the entire frame as a unit:


Flipped over, here's a view of what the completed table top frame will look like, sans finish of course:

One other minor task on the list was ticked next - fitting the T-nuts inside the legs, to which will be attached the levelers:


All for today, thanks for coming by. Your comments are always greatly welcomed. --> on to post 17

Wednesday, July 13, 2011

Coffee Anyone? (15)

Station 15 on the climb. If you're new here or haven't visited in a while, I'm in the late stages of a project to make a glass-topped coffee table with a joined bubinga frame and shelf. Previous posts in this thread, along with postings and threads on a variety of other topics can be found in the "Blog Archive" on the right side of the main page.

Last post ended with a cliffhanger of sorts, well, a different sort of hanger really, as I was mid-way through fitting a draw bar. The draw bar connects the main table top frame members together at their re-entrant corners:


The center of the bar is cut away with opposed rebates, a bridle joint if you like, to fit onto the twin tenons atop the leg. The gaps on the ends of the draw bar in the mortises are there deliberately, allowing room for some elastic compression as the joint gets mechanically drawn tight with the wedge pins, shachi-sen.

The tenons had been largely defined through the CNC stage of the work, however I needed to do some additional trimming:


And the same process with the front side:


Now I could try the fit, though some trimming is still to be done on those tenons in another location:


The last couple of millimeters required a little hammer and block assist:


Down:


Then I fitted the assembly of draw bar and leg to one of the frame members:


Then I fit the other side frame member to the assembly, independently, and finally was able to slide the whole shebang together:



The joint drew up decently:


A view from the front:


And a view looking up slightly from the front:


 Next, a view of the inside corner of the frame with the leg attached:


And for good measure, a side angle view of the connection:


 The joint isn't complete yet, mind you. I need to deal with the shachi-sen, which will lock the joint together tight. First task was the layout and knifing:


The other side:


Then I disassemble the works and complete the layout on the frames and the draw bar:


Time for an episode of Sawing for Teens:


And then some paring:


 The completed draw bar:


Then on to the trench cutting on the inside walls of the frame member end mortises, first sides:


 Then abutments:


The completed mortise:


Next post in this thread will have some pictures of the completed joint going together. Hope to see you then.  --> on to post 16