furniture making

Indispensable Gragg Chair Tool – 1/8″ Mortising Chisel

Making a Gragg chair requires chopping 17 mortises for their respective tenon partners.  No big deal.  Except these mortises are only 1/8″ wide.  For that task you obviously have to possess a 1/8″ mortising chisel.  You could get by with something 5/32″, but probably not 3/16″  The stock is just not beefy enough to try that.

I have three chisels in my arsenal for this process.  The first is one that came for a box of tools I got at a flea market, it is a 1/8″ long chisel with a turned bulb handle.  A second is from a no account 1/4″ Stanley chisel that I ground down to 1/8″ wide, and the third an my “go to” chisel is one I made from a derelict plow plane iron.  All three are delightfully short in their overall length, a definite advantage when working inside the quirky confines of of the Gragg chair.

The mortises in question are for the rungs and fitting the seat slat tenons into the underside of the crest rail.

I’m not sure if the 1/8″ mortise chisel is THE most important tool in the project, but I do know that Gragg himself did not use the mortise-and-tenon method for attaching the rungs – he just drilled full-size holes and punched the rungs through – and every Gragg chair I have seen is broken at this point.  This is definitely one case where an acolyte can improve on the methods of the master.  I once asked some engineers to analyze my approach with Gragg’s, and they told me the 1/8″ M-n-T construction was ultimately 4x to 5x less likely to fracture than the original.

 

Indispensable Gragg Chair Tool — Rasps

 

The Gragg chair is more like a sculptural assemblage of curvy parts in space and at several points in shaping the chair components there is only one tool type to suffice for the task, namely the rasp.  Or in my case, a few rasps and similar tools like floats.

I generally include four tools in this category; an Ariou cabinetmaker’s 10″ rasp (or its analog a Nicholson #50 patternmaker’s rasp),

a Shinto rasp, and a pair of fine Iwasaki floats, both flat and half-round.  In procedural order the processes requiring them are as follows.  Sorry about there being no picture but I could not find one in my compewder.  They’re there, I just cannot find them.

First is the touch up of the diminutive tenons for the rungs when the side units are assembled.  This is necessary only when the tenons are cut too full and need to be nibbled down to fit the mortises.  Generally I accomplish this task with either the Shinto rasp, if there a a fair bit to remove, or the flat Iwasaki float or small Ariou rasp if just a little.

Once the assembly of the cross elements begins I tend to concentrate on the front seat rail, letting the rear seat rail and the crest rail dimensions be established with tacking strips.  For the front seat rail the rasp is critical for two distinct steps.  First the curved surface of the end lap joints must be shaped to fit the underside of the serpentine leg element.  Though most of this step is accomplished with a saw and  chisel, the final fitting is fastest with the Shinto rasp.

Then, once the stock is fitted and affixed in place I remove the most of the square shoulders of the excess with a block plane but the configuration of space and the element means that the heavy lifting for roughing the shape (and the embedded half-blind dovetailed seat slats) falls to the rasp.

Fitting the crest rail to the tops of the serpentine pieces is a mix of saw and Shinto rasp, but the actual sculpting of the crest rail shape is accomplished through a combination of spokeshaves and the Ariou rasp, followed up with the pair of Iawsakis to get a surface ready to paint.

The final place for rasp work is both a “mere detail” and an elegant hallmark of a Gragg chair, the rounded glue block underneath the front of the curved arm and the meta-volute at the bottom terminus of the arm.  With the Ariou rasp I can usually cut these shapes into the square-ish stock in about 5-10 minutes.

Indispensable Gragg Chair Tools – Detail Saws

While not necessarily unique to making Gragg chairs a variety of detail saws are certainly part of several processes in the making of one.

Probably the most peculiar of these is cutting the curved dadoes in the rear seat rail to accept the bentwood seat/back slat elements.  While I know that making the curved bottom configuration of the dado can be achieved in multiple ways perhaps my favorite is to use a Japanese veneer saw, which with its deeply curved cutting edge is very well suited for the task.  One problem I have encountered recently is that I cannot seem to find  source for the saw, so I will probably attempt to make some myself.

One option I have tried is to employ a Japanese mortising saw, with some success.  The problem with this saw is the exceedingly long neck which causes some flopping around of the head.  I’ll probably order another saw and move the handle up next to the head.

Without having the saw in the tool kit it is possible to cut the margins of the dado with a small Japanese detail saw and then excavate the curved bottom of the groove with a bevel-down bench chisel.  Actually I find myself reaching for the Irwin and Shark saws far more often than I first expected.  Clearly, this Irwin has had a tough life in my carpentry kit, I need to re-cut teeth on it.

 

Elsewhere on the chair there is the need to cut the shoulders of the half blind dovetails on both the front and rear seat rails,

and the tenons on the ends of the back slats to insert their tops into the underside of the crest rail, and to cut the tenons on the ends of the rungs.  For these tasks pretty much any fine back saw will work, I go back and forth between my custom specced Bad Axe (now in their inventory), my treasured old Sears backsaw I bought new in about 1970, and my Japanese dovetail saw.  My habit is to cut the half blind dovetails with the Japanese dovetail saw and all the teeny tenons with the Bad Axe.

Next time – rasps.

Indispensable Gragg Chair Tool #3

One of the more challenging aspects of building a Gragg chair is the need to chop 17 half-blind dovetails for the ends of the seat slats, eleven on the front seat rail and six on the rear seat rail.  Unlike cutting half-blind dovetails in drawers or casework, the workpiece cannot be oriented to be most easy for the workman; these dovetails have to be cut after the chair frame is already assembled due to the fact as I have state before, making a Gragg chair is more akin to composing a sculpture in three dimensions than any other furniture-making exercise I have encountered.  Because of this there is no opportunity to adjust the orientation of the workpiece to the tool and the maker, requiring some contorted tool work.

In my development of techniques for replicating Gragg’s work, reverse engineering as he left no account of his own processes, I found the need for a task-specific dovetailing chisel is requisite.  I’ve tried working with fishtailed gouges, skew chisels, and probably a host of other tools lost in the fog of memory, but have settled on making my own tool which has now been in use for the past several chairs with excellent results.  The key is to make the business end of the tool match precisely the pocket being excavated.

In general there are two primary approaches to the problem, one much more expensive that the other.  The expensiver option is to take a 1/2″ curved fishtail gouge and regrind the tip configuration to match the angles of the pocket being excavated.  This yields an excellent tool for the task.  (Unfortunately, I think this tool fell into a crevice behind the workbench in the video studio and cannot be reclaimed unless I remove the siding on the exterior barn wall, an option I am loathe to even contemplate).

In my case, and probably in yours too, the problem was solved inexpensively by recycling a no-account cheep bench chisel from my scrap tool box.  Yes, alas (?), I keep an inventory of scrap tools along with scrap metal along with scrap ivory along with scrap tortoiseshell along with scrap wood…  Sometimes I think all our shops should just be call “the scrap yard.”  Part of me understands my late father-in-law’s mindset (and my late father’s as well) that it is difficult to dispose of materials that do indeed have utility.  Anyway, I took this old cheap Stanley bench chisel, probably available for a quarter at any tool swap or flea market, and ground away all the material I did not need for the final configuration.  This was an exquisitely efficient expenditure of time as this one tool reduced my time for cutting the half-blind dovetails in, well, half.

Door Days

One of the foci for shop projects for this winter will be a series of projects addressing the “door” needs around the place.

This will begin with the completion of fashioning the doors for Mrs. Barn’s small clothes cabinet I built a couple years ago.  I’ve had the vintage chestnut lumber picked out ever since the cabinet was made, but somehow that task never percolated to the top of the pile.

I’ve also got another eight doors to make for the book cases in the balcony library.  Again, I’ve had all the stock prepared awaiting assembly, and now is the time for that to happen.  I’ve not observed any mouse damage to the books yet, but given enough time it would occur.

Finally, I need to replace the double-plastic-sheet doors to the workshop.  They do a surprisingly good job but the time has come for real doors with real insulated glass.

Once all of these jobs get done I will turn my attention to the door(s) into the machine shop/foundry.  These doors were damaged long ago during a fierce wind and will be replaced by  a configuration still to be determined.  At the moment I am leaning toward a single door with a removable glazed wall alongside it.

Stay tuned.

More Woodpile Treasure

A while back a local friend brought me a pile of wood from his firewood pile.  Not until he cut and split it did he realize that it was a load of quilted cherry.  Quick as a bunny he brought it over, and I have been waiting for the best time to saw it up into usable boards.  Unfortunately that time has not yet come, but my eyes glance over to the pile every time I go down to the first floor of the barn to feed the stove.

Even when viewing it along the cleavage line from splitting it is clear there is something pretty special inside.  A few minutes with a scrub plane and fore plane, followed by a dousing of shellac, confirms the initial optimism.  Given the firewood-size of the pieces, this one was about eight inches wide, I’m thinking of some particularly figured panels or small-ish boxes.

Spectacular, and I am betting that if you have a firewood pile there is plenty of woodworking and woodturning treasure in there too.

Workbench Wednesday – Hoisting 1, Building 2

In addition to bending all the necessary parts for next August’s Build A Gragg Chair workshop John and I spent some time setting up the attic for the event as it is the only space in the barn large enough for the activity.  I already had two eight-foot workbenches up there, but in order for all the participants to have their own bench we needed three more.

One of them was a simple problem to solve, at least conceptually.  Just take one of the benches from the classroom space on the second floor and host it up with my vintage compound block-and-tackle.  We did accomplish that but we are definitely not as young and probably not as strong as we once were.  Plus John probably weighs about a buck fifty if you put bricks in his pockets.   Even with a compound hoist, a 350-pound bench weighs 350 pounds.

But hoist it up there we did.

For the other two I made two more Nicholson benches after carrying the individual boards up the stairs one at a time, definitely an easier path to glory.  At the moment they are sans vises and holdfast holes but that will be rectified soon enough.

Now my total workbench inventory for the barn is 19, an entirely appropriate number in my opinion.  This is probably the end of the run for new Nicholsons or laminated Roubos as the recent prices for lumber have definitely scared me off.  For example, I recently needed two ordinary (untreated) twelve-foot 2x8s, they were $23 apiece.  The 24-foot 2x12s I’ve been buying for workbenches used to be $54, now they are $97.  Fortunately I had just enough of my old inventory to build these two benches.

Parts Is Parts

During our recent days of work preparing for next August’s “Build A Gragg Chair” workshop my  friend John and I prepped a lot of wood sticks, and bent them to the forms required to become Gragg chair parts.

We got the steam box set up, the forms set out, and set to work.

John hand planed dozens of chair pieces to get them ready for the thermodynamic adventure.

 

Once he had five or six pieces ready to go, he used the template board I created for this purpose and affixed the bending straps to all the pieces.  When you have to execute two 90-degree bends only twelve inches apart in a dozen seconds, bending straps are pretty much mandated.  We used flanged sheet metal screws and plumbing straps and attached them BEFORE they went into the steam box because the brief time to get the bending done after steaming does not allow for the straps to be put in place afterwards.  And since the chairs get completely painted, any staining or screw holes can be dealt with.

I placed them into the already heating box and waited for them to reach maximum temperature, which in my set-up is about 200 degrees.

Using a state-of-the-art steam box seal we set the timer and waited the requisite time, 25 minutes for the arm and serpentine pieces, 45 minutes for the bent seat/backs.

On the first day we had good success especially with the thin pieces, only one failure out of eight or ten attempts, but on the second day we had a string of failures approaching 50% when bending the continuous seat/back slats.

At that moment we could discern no reason for the degree of failure  We needed to re-think our process.

Prepping (for Gragg Workshop)

I could probably maintain a steady stream of posts exhorting you to prepare for the ongoing (and upcoming) societal chaos, but since this is a mostly woodworking blog I’ll just keep it there.  My commentary on the global status quo mostly remains reserved for private correspondence.

Since deciding to host and teach a “Make A Gragg Chair” workshop next August I have been focusing in on preparing the fourth floor space and the necessary chair-making elements for that enterprise.  This week my dear friend John has come to work with me in both aspects, which include the mundane (tidying and reorganizing the space) and the sublime (steam bending all the elements needed for five chairs — I will be making one right alongside the students so they can witness the way I do things, not simply receive my instructions on that).

I described myself to some visitors last week as “someone who is congenial with well-developed social skills but is entirely comfortable being alone for weeks and months at a time with just Mrs. Barn for company,” I find the circle of friends whose company I seek out is pretty small.  John is one of those men.  Our week will be one of productivity, in-depth discussions of forbidden topics, and maybe even some way-out-of-bounds activities reflecting the fact that I live in a just-barely-free jurisdiction and he does not (some/many/most? “public officials” have clearly mistaken 1984 as an instruction manual rather than a cautionary tale.).

So together John and I will take a pile of sticks and turn them into chair parts.

Stay tuned.

Final Gragg Video Session

It seems like it was almost three years ago that videographer Chris Swecker and I met over lunch to brainstorm about producing videos in the Attic Studios of The Barn On White Run documenting the entire process of building the premier version of a Samuel Gragg Elastic Chair.  Oh wait, it was almost three years ago.

Last week we actually concluded the video capture portion of the project in our 18th (!) recording session, resulting in almost 34 hours (!!) worth of electrons in the can.  Or, 68 hours if you calculate the close-up work that was simultaneous to the wide screen shots.  Now comes the tedium of my reviewing every second of video to create Cut Sheets which are the road map for Chris to execute the editing and final assembly.

This final session was a bit of a grab-bag as you might expect, completing the project but also juggling in several other elements to be captured in a non-linear schedule for the day.  In a conceptually linear recitation of the content, we began with the primed chair, then mixing the fill putty and inserted it into all the spaces that needed a bit of filling.

 

That was followed by a through sanding of the entire surface in preparation of the final cream-color base coat.

We wrapped up that portion with a discussion of the variety of striping brushes in my kit, followed by a short demo of pinstriping.  The entire pinstriping process is too lengthy to record live so we will instead rely on a gallery of step by step still shots for instructional purposes.  If you will recall the recorded the painting of the peacock feather by my dear friend Daniela last year.

We wrapped up the content with a final session of our bonus video on the restoration of my first full-to-the-brim Gragg chair from a decade ago that had its arms crushed.

It has certainly come a long way.

I now have to construct the entire contents into chapters, the subjects of which are likely to be:

  1. Harvesting The Wood

2. Preparing The Stock

3. Creating the Patterns

4. Building The Forms

5. Steam Bending The Elements

6. Assembling the Side Structures

7. Fitting the Seat and Crest Rails and Rungs

8. Fitting and Installing the Continuous Slats

9. Fitting and Installing the Seat Slats

10. Sculpting the Chair

11. Painting

12. Pinstriping

13. The Peacock Feather

14. Bonus – Conserving the Damaged Gragg Chair

My goal is to have each of these sections 45-60 minutes long, perhaps with more detail than a casual viewer would like but more akin to what a maker would want.

I am diligently reviewing the raw videos for an hour or two each day and will forward the Cut Sheets to Chris as they emerge from the process so he can begin the editing and assembling right away.