Sunday, January 30, 2011

Sunday ToolFoolery: Building An Improved Steam-Bending Box

Hot on the heels of its inaugural run, I thought I'd post the design of my improved steam-bending box.  I really wanted to "turn it up to 11" -- both to remove any doubt about whether I was getting the wood pliable enough for chair leg bending, but also with an eye to building a nice little high-transomed rowboat for our pond.

The first decision I made was to move from electric to propane power.  This came at a cost, as it forced me to move my bending outdoors (I've moved it to the shop for glam photos.)  The intensity and number of warnings on the instructions convinced me that stoking this thing up under cover -- even in the garage, was a death wish.  So out it went.

The only real "innovation" is the sliding box-within-a-box that allows it to go from three feet to six feet in length.

A short run of galvanized, 2" pipe attaches to a rubber doohickey that couples the 1 3/4" spout of the petrol can to the OD of the 2" pipe.  Needless to say, this is a new petrol can, and I was surprised at how robust it was under fire.  It holds two gallons of water.  Much to my surprise, this was not enough for the 2 1/2 hour burn.  Refilling it with boiling water was easy via a funnel.

Although I've been referring to it as the "Bayou Burner", the heat source is actually a Bayou Classic High Pressure Burner that I found on Amazon.  All of the fittings should be available at your local home center, and I don't see why you couldn't replace the steel with PVC.

When in full flight, it maintained a constant temperature of 200 degrees F and belched out a goodly amount of steam.

Feel free to shoot me any questions.  Thanks for reading!

Thursday, January 27, 2011

A Pair of Contemporary Chairs, A Mt. Lebanon Side Chair, and NDB (New Bird Day)

There's nothing like hoisting a big beautiful hunk of 8/4 oak onto the bandsaw to test the courage of your design convictions.  I love oak, the "monarch of timbers" -- it's tough, but responds to handtools, it's heavy, but its strength allows you to create graceful forms.  And it bends well -- unlike hard maple -- but I don't want to give away the end of this tale.

After laying out my final design for the contemporary chair on plywood, I cut the template, and using a flexible sanding stick, faired all the curves.  I then transferred this to my stock and cut to within 1/16" of the line.  Using a honking big piloted spiral router bit (that I bought during my brief foray into guitar building), I brought the shape to its near final form.  One mistake I made was not cutting the template a couple of inches over length on both ends to avoid grabbing end grain.  I did, however, cut the stock long and I was able to baby it through the process.

I thought about noodling through the joinery before I cut the components, but one thing I have learned about chairs is that the most accurate way to hit your mark is to start building and cut pieces to fit the developing form.  Using loose tenon joinery also helps with that approach.

The next step is to cut the mortices with my router and shop-made morticing jig -- a Frankenstein's monster if you ever saw one.  To get the angle from front to back of the seat, I used the bevel gauge to cut wedges and placed these under my plunge router.  Now, all I need to do is line up the legs in the jig, determine the distance of the mortice from either the outside or inside face of the stock (it doesn't matter which, as long as you are consistent), and take multiple passes with the router to a depth of 1 1/4".  If this sounds swift and easy, it was not.  I woke up several nights puzzling through the joinery and I was on my toes the whole time.

After cutting the side rail mortices I inserted little tenons to ensure that the angles were correct and look at the way things were progressing.  Right away, I noticed that my original dimensions seemed too massive and I adjusted accordingly.  My next step is to cut the side rails, scribe the actual angle that they meet the front and back legs, and compare that to my original "Master Angle".  I will then fit (what should be) the front and back rails at the correct 90 degree angles.  Ahhh. . . the joys of a prototype.

Now that the correct parts have arrived, it is time to give the new steambox its inaugural run.  The "Bayou Burner" did everything that it promised and really put out the BTU's.

The temperature stayed consistent at 200 degrees F and the steam just poured out the front and back.

My steam-bending experience is exclusively with oak, and I was up for a surprise bending this hard maple.  I gave the back slats 45 minutes, and secured them in their form.  Not bad, but I would have thought it would be more pliable.

The back legs cooked for two plus hours and were more of a challenge.  I expected that, like oak, the legs would come out of the hot-box just a-steaming -- but they were made of sterner stuff.  Jump in if you know the answer, but it seems that maple, much less porous than oak, really doesn't want to take in any of the water.  I wrenched them into their form with some difficulty.  I am expecting some serious spring back.

Strictly from an ecological point of view I really didn't like working maple in this fashion.  Using all that energy to force the material to do something it didn't want to do seems a waste of time and resources.  It gives me new insight into the wisdom behind stock selection with Windsor chairs.

As the above picture illustrates, we got a bit of snow last night -- fifteen inches to be precise, and it brought our house to a standstill.  But, it's an ill wind that blows no good, (as they say) and the upside is that it allowed me to add a new bird to my life list.  A pair of Ring-Necked Ducks, a smallish diving bird, took refuge on our pond.  They will probably split after the snow melts, but they were a most welcome surprise.

Next, I'll install the rails on the contemporary chairs and (hopefully) complete the Mt Lebanon Side Chair.

Stay warm!

Friday, January 21, 2011

A Pair of Contemporary Chairs: Layout and Design

Never fear, you didn't miss any steps in the construction of the Mt. Lebanon Side Chair.  My efforts to improve my steam rig have backfired a bit, and caused a slight delay in the project.  After building an upgraded box, with options for expansion, and enlarging my fittings to an inside dimension of 1 1/2", and increasing water capacity by using a 2 gallon gas can, my first run was a bit of a damp squib.  It seems that the 1000 watt hotplate didn't have enough gumption to get the job done.  Maximum temp. in the box: 155 degress farenheit.  So, if Amazon cooperates, the mighty "Bayou Burner" should arrive today with 185,000 btu's of propane muscle that will allow me to power a small locomotive.

Meanwhile. . . I was approached about building a pair of upholstered chairs.  Modeled on the photo below, made of oak, and with a deadline.  So I thought I'd go over the way I lay out a project when I don't have a set of plans.

The first order of business is to say that I don't make direct copies of other people's work unless they put the plans out in the public domain.  I wouldn't, say, make a "Mira" chair and sell it -- not cool.  This piece is a fairly standard contemporary design, by an unknown manufacturer, and I'm using it only for inspiration.

I call this approach "furniture lofting" as it is inspired by my very limited knowledge of boat building.  By drawing the actual piece (templates, angles, and dimensions) I save myself heaps of frustration and define techniques and form a loose cut list.  I start with the most important element, the double curve of the back leg/post.

A couple of things are going on here at the same time.  First, I'm looking at the design -- how dramatic is the curve, what are acceptable chair dimensions, where can I anchor a known dimension to get the proportions right.  And second, I'm trying to nail down the technique.  In this case, will the profile be cut from stock, steam bent, or laminated.  Steam bending would be tough.  The stock in some points is more than 2 inches wide, and unless I felt lucky, I'd need to bend it first and then do the profiling.  Lamination makes a lot of sense, but again, I'd need to form it to the inside curve and then profile it -- running the risk of a bunch of lamination run-out along a very visible edge.  In this case, as the curves are not too dramatic and I have a lot of faith in the strength of oak, I think I will cut the profile from the stock.  The downside is that there will be some concern about short grain, but in this thick stock I believe it to be less of an issue.

Using a pair of splines, and starting with a 1 1/2" block glued to the plywood to mimic the width of the foot, I start to lay out the design.  I align the profile of the leg with the short edge of the plywood as the floor, and the long edge as the vertical axis.  This means that in order to simplify the joinery, I want a flat spot from 10" to 13" up the front face of the leg.  It is at this point that the side rail will meet the leg.  Adding six or so inches in height for the cushion and batting will net me a final seat height of around 19 inches.  I make this spot flat by glueing a 3 inch block.  The rest is by eye.  I first wanted a final height of 35 inches, then felt that 37 looked better.  I glued one more block, fiddled with some clamps, and was happy with the look.

I use a similar method to lay out the shorter front legs, but I raise the flat by 1/2 inch.  That will tilt the chair back slightly, without any compound joinery.

What did I learn.  First, I  have a template that looks good - in actual size.  Second, without even fiddling about, I determine that eight inch wide, 8/4 stock, will accomodate back leg pattern with space for the front leg.  If it were any wider, I'd be kicking in a price multiplier at my supplier.  As it stands, I can get a handle on my stock needs and begin calculating board feet.  For every two legs (approx. 3 feet x 2" x 8/12 wide) I'll need 4 board feet. 

I lay out the seat joinery by drawing an actual-sized overhead view.  Four 2" by 2" block stand in for the legs and I start with my final front and rear dimensions.  Like most seats, it will be slightly wider at the front than at the back.  I settle on 24 inches at the back, and 27 inches at the front.  I also decide on 27 inches for the final length of the combined seat posts and side rails.  Drawing these dimensions on my board, and taking advantage of the right angles that exist, I can quickly place the posts. I draw centerlines on the posts and connect the lines of the trapezoid.  The front and rear rails are easy -- 23 and 20 inches with right angle joinery.  The side rails are different -- but it doesn't matter, I'll be making a template from the drawing, and in this case, making a mock-up before I go live.  I do take one measure with the bevel gauge to get the Master Angle.  This angle, and its supplement, will determine how the side rails meet the posts.

I'm choosing to go with loose tenon joinery on this project, and that means that the net and gross dimensions of all parts are the same.  The bevel will determine the angle I place the posts in the jig later.

And that's where I'll pick up next week!

Thanks for reading.

Sunday, January 16, 2011

Sunday Toolfoolery - A Shop Made Steady Rest, A Center Marker and Some Bending Jigs

Without a doubt, I've been spending more time making jigs than making furniture in the last few weeks.  It wouldn't bother me so much, but my track record with these shop aids, especially when I start freelancing on their design, is decidedly poor.  When one doesn't work, I usually just strip off its parts and move on, trying not to think about the time I wasted.  But when I spend a good solid week on nothing but jigs, I'd like them to pan out in the long run.

The Steady Rest
One that has already proved useful is my shop-made steady rest.  I'm willing to entertain the idea that this is unnecessary, that a real turner just wards off chatter with good technique and a calloused palm, but I like the stability it gives me on these long shaker chair legs.

It starts with an approximately 4" hole cut in a piece that runs perpendicular to your lathe bed.  The center of this hole is exactly the height of your lathe centers.  This is easily determined by standing the board on end and squeezing it between the head and tail stock.  This is secured in place by attaching it at a 90 degree angle to a board that rides on the lathe bed.  It is held square with a rail. 

In order to hold your work steady, this rest must contact a perfectly round spot at several points around the circumference.  This is done via four sliding bars with wheels on the end -- well, not exactly wheels, but skateboard bearings.   So along with my order for some aluminum rail, and some other jiggy screws and handles, came a little red package that looks surprisingly like contraband. (The complete plans for this come from Fine Woodworking, Issue 143.)

The Center Marker
Designed to mark the centerline of your turned piece, this is necessary to keep the axis of the back rungs and the back slats aligned.  It is basically an L-Shaped piece of wood with a hole drilled for a pencil.  Like drilling the hole for the steady rest, the hole for the pencil lines up with your head and tail stock centers.  Once you have finished turning, you just slide it down the bed to mark your center line.

The Back Slat Bending Jig
This is taken directly from Kerry Pierce's Authentic Shaker Furniture Furniture plans -- with one modification.  I attached oak slats on the sides so that it will stay aligned when bending a group of slats.  Now I just pop the steamed slats in all it once, put the jig in my front vice, and crank it down tight.

The Leg Bending Jig
I fiddled with Pierce's idea more than I should have to develop my version.  His plans are very simple -- the legs slide into a hole on the bottom, wrap around the form, and are drawn together with a big hose clamp at the top.  I wanted to have the flexibility to do thinner and shorter legs, so on my version I secure the leg to the forms with C-clamps.  If I want to make a children's chair I can start the bottom of the leg higher up the form to make the leg begin its bend at, say, 15 inches instead of 19 inches.  Time will tell if this is an improvement or a nuisance.

By the way, I want to make a strong recommendation for the book in the opening photo.  I seem to have become a collector of Kerry Pierce books and this one is my favorite.  Chairmaking Simplified is readily available, packed with information about chair construction (and jigs!), and the sections on splint, rush, and cane seat weaving are invaluable.

Now, if the parts for my improved steam-bending rig come soon, I'll feature some bending on Thursday.

Thanks for reading!

Thursday, January 13, 2011

Building A Mt. Lebanon Side Chair: Turning and Thinking

I've never built a post-and-rung chair before, and I'm amazed at how slowly I progress when I'm trying to simultaneously work wood, make jigs, plan the next step, and visualize the final product.  Maybe this is just a fancy way to say that I'm way behind schedule on this project.

However, there may be more to it than that.  Each of us has our own way of working, and even when we are following a set of plans or copying someone else's jigs, we are constantly asking "Does this work for me?" Or, "Is this like something I've completed (successfully) in the past?" I'm constantly wondering "If I'm going to do this 20 more times, is this the best method?"

The turning of the long back posts is one example.  I can fit the 43" long maple blank on my lathe, but  something this long and thin presents a number of issues.  I normally think cutting a blank into an octagon (as opposed to starting square) is a bit of a faff, but in this case, it seems wise.  Anything that avoids placing too much stress on the blank is a good thing -- plus, you can place your palm on the spinning octagon in a way that you cannot on a square.  "Should I use a steady rest?"   Designed to hold long spindles in place, it requires that you start by creating a perfectly round portion in the middle of the spindle.  (The answer for me was, "Yes" and I'll outline my shop made version on Sunday.)

Turning at the lathe is sure to bring out your idiosyncrasies.  I like to move from my right to my left, turn at as high a speed as possible, and sand as little as possible.  "How can I do that with this piece?"  The steady rest was a big help, and I roughed the cylinder at 1300, defined the taper from the seat top mark (19 3/4") to the post top at 1500, and sanded at 1800.  The taper went from 1 7/16" to 1" at the top.  I tapered using the same method I use when tapering a table leg with a hand plane -- I start 1" from the top and take a thin pass, then 2", then 3", until I'm taking a pass along the entire taper.  I repeat until I've achieved the dimensions I need.

The most important part of this piece, at least visually, is the finial atop this back leg.  It punctuates the chair and defines it among the many Shaker chair-building communities.  Again, on a detail like this I think, "What are the steps that will, if executed correctly, result in that form?"  I'm not thinking, "How do I copy that?"  For me that distinction is important and hard to explain.

I believe that forms like this come about because an artisan has a method of work that is unique to him or her.  They go through a series of steps -- move the gouge here, cut this cove, taper down to the cove. I think that it is this process, as opposed to simply thinking of a design and doing whatever it takes to get there, that defines the look and proportions of what I call "vernacular" furniture -- furniture worked by hand to be placed in a working environment.  Reproductions always carry the weight of a pre-conceived form, but I still think that your best results come from copying the methods, not copying just what you see.  It is in some ways, a digital rather than an analog reproduction.

Drilling the 5/8" holes for the rungs is the next step for these posts.  While still in the lathe, draw a centerline down the entire length of the leg (I'll talk about this jig on Sunday as well.)  This line is not critical to center the rung holes, since the jig will do this, but it is critical to put the rung holes and the back slat holes in the same axis (more about this later.)  When setting up the jig you set the tip of the Forstner bit one-half of the diameter of the post from the fence. You place the leg in the Front Rung Mortise Jig, align the center line with the Forstner bit tip, and secure the leg with a screw at the end of the sliding platform.  Drill to a depth of 15/16" -- which is 1/16" more than the 7/8" tenon that will be turned on the rungs.

The front posts are much easier, as they are shorter, and proceed in a similar fashion.  When working with plans, I always create story sticks.  Each set of rungs are placed at different dimensions and it would be easy to get confused.  Clear your head, make your marks, and double check your work before you move to the drill press.  When turning the front posts, I found it helpful to turn one a few inches longer, drill one of your rung holes in this extra length, and then trim the leg to the correct dimension.  You can use this drilled off-cut to check the fit of the rung tenons in the next step.

The front rungs are turned to a dimension of 15/16" and the rear to 7/8".  On each of these rungs you will turn a 7/8" long by 5/8" wide tenon.  The rung itself will taper from the center to each end leaving a 1/16" shoulder at the tenon.  I turned to maximum dimension, then formed the tenons, then put in the taper.  The taper is visual, you are not turning to a specific fit.

Turning the tenons, is a different matter.  Hard maple leaves you very little room to maneuver, and as you are not tapering this tenon and placing it in a reamed mortise (like in a Windsor Chair) there is no room for error.  Use your calipers, set on the 5/8" bit itself, and turn to this dimension.  I don't find this to be fool-proof, so I tip-toed up to the fit, checking it on the rung hole mortise I drilled on the off cut.  It was slow and tedious and I will be changing this method.  Options include one of those Sorby Sizing tools (which seems fiddly), Peter Galbert's Calipers (which I've used, and like very much) or the old open-ended wrench while using the parting tool one-handed trick.  All of these would benefit from the use of a flat-edged, slightly wider, parting tool (ordered today.)

Once the tenons were turned, I enjoyed that squeaky hard-maple-on-hard-maple sound of a good, tight fit.

Next, I'll be making the steam bending jigs, cutting and shaping the back slats, and maybe even doing a bit of bending.  Thanks for reading!

Friday, January 7, 2011

Building A Mt. Lebanon Shaker Chair - Jigs and History

Once this Shaker thing gets a hold on you, it's hard to shake off its allure.  While doing the research for the tables, I started to be drawn into the complicated web of Shaker chairs.  I suppose that it is because, like Stanley planes or English silver, there are a set of markers on each piece that allow you to identify their date, community, and even the individual makers.  Understanding this brings order, and (sometimes) order is a good thing.

When embarking on a project like this I often end up referring to two sources -- one directive and instructional, the other more qualitative and expansive.  In this case I found two excellent sources of information that fit the bill.  The first, I must say, is a masterpiece.  The Shaker Chair, by Charles R. Muller and Timothy D. Rieman pulls together a vast amount of information about Shaker chairs -- from standard rockers to makeshift wheelchairs -- and the communities who made them.  In its profiles of individual craftsman like Freegift Wells and Robert M. Wagan, it tells the story of the chair's path from utilitarian furniture to iconic symbol of American design.  And if that wasn't enough, it comes with a big fold-out wall diagram that compares styles across time and among communities.  I haven't been this excited about a poster since the one of Farrah Fawcett-Majors that hung in my high school bedroom.

Kerry Pierce's book, Authentic Shaker Furniture is a very good, straight-forward how-to book.  Loaded with photos and a great deal of descriptive text, he is honest about his strengths and weaknesses as a craftsman.  He gets the most of of a modestly-equipped workshop -- and I mean that as a compliment.  I think a beginning woodworker could take a project from start to finish under his tutelage.

In my opinion, chairmaking is one of those specialized woodcrafts like boatmaking or woodturning that can require a whole different mindset.  No piece of furniture is expected to be as strong or as graceful as a chair, and successful pieces use geometry and physics to their advantage.  This chair will more or less follow Pierce's dimensions for a a #6 side chair from the Mt. Lebanon community of New York State.  Within that genre, it is modeled on a chair that would have been built by the grandaddy himself, Robert M. Wagan.  Wagan, quite literally, turned that community into a chair-making factory, and many of the pieces that survive today come directly from his influence.

Chairmaking also lends itself well to the use of jigs. . . and because Kerry Pierce never met a jig he didn't like (see his book, Quick and Easy Jigs and Fixtures ) I'm starting with two of his most popular contraptions.  Just a word about chairs in general (from someone who is not a chair specialist.)  Chairs are all about materials and angles.  Select the right stock and they will last; noodle through the correct angle and they will come together like a dream.  In my limited Windsor chair making experience, I always measured and drilled by hand, setting legs and spindles with my Fray brace and a bevel gauge. In this case, I'm building two jigs that will help me drill the holes for what is, by category, a post and rung project.  If I don't explain it well today, hang in there until next week as I will show them in use.

Front Rung Mortise Jig
OK, here is what I will not do.  I will not reproduce Pierce's jigs and pass off something that he worked hard to design for free.  For complete instructions, I encourage you to buy his book.  I will however, show you the jigs and tell you how they are used and clear up a couple of points of confusion.

This jig will allow you to drill the holes for the rungs that connect the back posts together into a "ladder" and the front posts together (also in a "ladder".)  This is a simple 90 degree hole drilled into the dead center of the post.  On this chair there are two back rungs and three front rungs.  The top rungs are also referred to as seat rungs as the seat material will be woven around these "stretchers".  The jig itself allows you to set a fixed distance from the fence to drill your hole, and then lets you slide the post along so that you can drill additional holes on the same axis.  It lies flat on your drill press table.

Side Rung Mortise Jig
If chairs were like boxes, you could take those completed "ladders" and drill another set of 90 degree holes and insert the side rungs -- but they are not.  Most chairs are wider in the front than they are in the back.  Another way of saying that is that the front rungs are slightly longer than the back rungs.  In order to accommodate this difference, the angles between the back rungs and the side rungs are slightly obtuse, and the angles between the front rungs and the side rungs are slightly acute.  This difference will always result in supplementary angles (92 and 88, etc.) 

This jig allows you to insert the entire "ladder", angle the jig a couple of degrees (with a wedge) off the 90 degree table, and drill holes.  Rotating the jig 180 degrees on the table allows you to the cut the supplementary angle on the opposite side.  Many plans will tell you this angle, and you can work backwards to create the appropriate wedges.  More on this later.

Next week, I promise to raise a tool in anger in order to start making a chair, but still have a couple of little jigs to help with the turning.  I'm not ashamed to admit that this is the first time that I've ever spent an entire week simply making jigs, and I do not wish to repeat this experience.

Thanks for reading!

Monday, January 3, 2011

Shaker Side Tables: Finally Finished

My two favorite ways to finish cherry always come under fire for being both finicky and not very durable. -- but I've never had any problems.  I use Tried and True oil, with its honey like consistency and non-toxic pedigree, when I want very little sheen.  When I want to dial in the desired amount of gloss, I go with boiled linseed oil and paste wax.  On my three Shaker tables I went with the latter.  All received just one coat of boiled linseed oil. On the two round-topped stands I applied two coats of wax, on the drawered stand I applied just one.  Some final thoughts:

Shaker Round Table

It is no surprise that this simple, elegant form is the most recognizable piece of Shaker furniture.  In my eyes, its success relies upon the profile of the pedestal and the graceful curves of the legs.  The top is secured with a support that travels across the grain to reduce cupping.  I've secured it with brass inserts and brass screws, leaving ample room in the support for wood movement.

Shaker Single Drawer Stand

I really like the utility of this little table.  the pedestal is the shortest of the three, and there is no apology for its straight-forward design.  The subtle snake-legs are a focal point and, for better or worse, the center board on the top displays some quarter-sawn figure.  The double-sided drawer rides on guides that affix to its side.  I used a bit of curly cherry for the drawer fronts, and the oil really makes them pop.

Imperfection #1

This is the only one of the three tables where I made radical alterations to the traditional Shaker design.  The maple butterfly keys span two largish checks, and the top is thicker than normal.  The tilt-top mechanism is of my own design, in the hope of reducing the bulk of a traditional "bird-cage" tilter.  When horizontal, the top rests on a turned button affixed to the pedestal.


I must say that I love working with cherry.  It is easily worked with hand tools, it is economical to buy, and the figure never disappoints.  Living here in Pennsylvania, it is quite plentiful, and my local hardwood suppliers always have interesting shorts and flitches that make great table tops and seats.

During the past couple of weeks I've been doing a good bit of research about Shaker chairs -- their design, manufacture, and evolution over the years and across the various communities.  As I start the new year, I will be making a pair of New Lebanon side chairs in maple.  The project will include lots of turning, steam-bending, and seat weaving. . .  and I'll begin making the jigs that will speed production in my next post.

Thanks for reading!