Musings

Compewders :-(

Starting about two weeks ago my laptop has been a dysfunctional ornament, preventing any meaningful work including blogging.  There are people smart enough to create new posts using their Kindle or smart phone, I am not one of those people.  Besides, my Kindle does not have access to my photo folders.

Stay tuned.  If you hear a loud noise that might be me ventilating this thing with a sporting implement.

Gragg Chair Workshop 5

With the incorporation of the continuous seat/back slats the artifacts began to adopt the true character of a Gragg chair.

There’s not really a lot to say about the process; you thin the vertical sections to impart the requisite springiness (this is where clamping/vise weirdness is a feature, not a bug), mark, cut and excavate the dado troughs in the rear seat rail, and lay out the half-blind dovetails on the front set rail and the mortises in the crest rail.  It sounds so mundane to describe many hours of intense work thusly.

One “complication” is that the slats must be off-set front-to-back so that they are staggered in order to impart the “elastic” leaf spring function to the chair as a whole.  The is accomplished by using spacers between the slats just above the rear seat rail.  Only after this configuration is achieved can the half-blind dovetails in the front seat rail be layed out and cut.

The dovetails themselves are a piece of cake, literally a minute or two per joint.  The pocket mortises chopped into the rear edge of the front seat rail are a bit more involved but still not hysterically complex.

Once this is done the tops of the slats can be marked and the tenons cut.

Gragg Chair Workshop 2

 

Early on Day 2 everyone had their side units assembled and thus began one of the more frustrating parts — getting the baby up on its feet.  As I often say about Gragg chairs, you are not so much constructing a chair as you are assembling curvilinear sculpture in three-dimensional space.

To assist in the process I had constructed for each student an assembly jig including four stirrups indicating the location of the four feet.  Combined with a few diagonal struts held in place by spring clamps, the correct posture was assured with the use of a bevel gauge to make sure each side was canting in the proper direction at the correct inclination.  Now it was time to start fabricating and fitting the cross-chair elements, the front seat rail, the rear seat rail, and the crest rail.  It sounds so simple but when you start fitting structural elements to curved and tapered components it suddenly is much less simple.

I learned two important items today to add to the “To Do” list in case I ever host this workshop again: 1) make a story stick for each student so they do not have to spend so much time measuring and remeasuring, and 2) have a fully dis-assemble-able chair so that it is quicker for me to explain how the parts fit together.  I am working on that project right now.  Perhaps a third thing is the hindrance of always working alone, repeatedly I would find myself forgetting to say out loud parts of the conversations going on inside my had, conversations that actually yield useful information about the “whys” and “hows ” of doing things.

The easiest of the cross-chair structural elements is the front seat rail, so that is where I had the students begin.  I had found that using a Zyliss vise is most beneficial to the Gragg chair building process so I made sure each workbench was outfitted with one.  By the end of the class each student was a big fan of the tool.

Near the end of the day it was a thrill to see the inventory of chair forms emerging on the assembly table.

Gragg Chair Workshop I

With the three students in-house by Sunday evening of last week, we began with a quick tour of the attic space we would be using for the chair building; it was the only space large enough for the four of us to be building four chairs simultaneously.  We were delighting in the acquaintance-making yet tempered with the knowledge that the fourth student, one of my earliest and most ardent Gragg enthusiasts, had died suddenly and unexpectedly last month while I was preparing for the workshop.  His memory was never far from my mind through the week.

We then descended to my second floor studio where I treated them to the uninterrupted (except for my commentary) hour-long time lapse video of my “40-hour Challenge,” allowing them to see the entire process from beginning to end.  With that, we were ready to hit the ground running Monday morning.

Gragg Chair Workshop : T-Minus Seven Days

Next Monday will be the first day of the inaugural “Build A Gragg Chair” workshop at the barn.   I’ve been aiming for this week for the past decade.   For a couple weeks I have been preparing the space up on the fourth floor, the space normally used as my video studio.  It was the only place in the barn with enough open space for four workbenches, assembly tables, and the steam box.

In addition to getting everything tidied up I built three additional assembly jigs and steam bent a few of the parts I forgot to do when my pal JohnH was here earlier getting all the parts bent for student use.  That’s the only way we could get chairs built in six days, having all the individual steam-bent parts ready in advance.

It’s gonna be a gas.

I’m praying for cooler weather as last week was the hottest here in fifteen years; it was near 100 in the barn attic.  It has since cooled down to normal and I hope it remains so, high 70s in the day and mid-50s at night.

Ex Poste Analysis (Mel’s Wax) – Part II, The Cause

NB – This is not only my 1,500th(!) blog post over the past 8+ years, it is the longest one I’ve ever written.  By far.  Normally a post takes me from 30-90 minutes to create, occasionally longer or shorter.  For this one, depending on your timekeeping system it took me a) four weeks, b) four months, c) four years, or d) four decades.  So which one was it? 

The correct answer is, “Yes.”

In order to tell this tale with some completeness I need to give you a tiny bit of background context.  (In truth it turned out to be something more than a “tiny bit” but it is far less than a proper detailed exposition.  I think that would be too much for 99.8% of you, and since I have about 300 readers that pretty much eliminates everybody — DCW)

To determine the cause of the soup-iness of the batch of Mel’s Wax, it should be the viscosity of a lotion and was instead the viscosity of heavy cream, I needed to go back to the beginning to reflect on the original concept for the formulation.  This will be  long and winding tale but provides the fullest possible explanation I am able to share about the reason for the batch “failure” (as I said earlier it was not really a failure, it was just not the precise outcome I had expected.  In the end it turned out just fine.)   I should probably break it up into three or four posts, but I decided to just put in one big steak rather than several smaller burgers.  So, settle in with a snack and your preferred beverage for this ride.  I don’t think you necessarily need to buckle up, but if a discussion of solvent thermodynamics gets you all worked up into a rave perhaps you need to restrain yourself as well.

BTW This post borrows heavily from the section that has been the bane for the past year of writing A Period Finisher’s Manual.  And yes I have finally solved that particular puzzle and am back at work on APFM almost daily.  Yup, it has taken me over a year to get a handle on one part of one chapter.  Were it not so important to the craft of wood finishing I would not have bothered, but it is and I did.

From the beginning of our careers, even before we met and worked together, Mel and I formulated and mixed our own furniture maintenance polishes because we were not content with the products in the market.  The commercially available products often used ingredients we knew  a priori to be potentially deleterious to historic finishes, or used ingredients in proportions we thought were not optimal (for the furniture), or were simply too difficult to use.

So, the product Mel finally derived (I withdrew from direct participation fairly early for logistical reasons once we knew the development was on the right track; the easiest way for the project to move forward was for me as Mel’s Supervisor to assign him the task of taking it to fruition with me providing oversight and the occasional observation, review, or suggestion.  Participating directly, as a Supervisor and programmatic manager [read: fiduciary] would have been an administrative nightmare) fulfilled splendidly our goals for “the ultimate furniture polish.”  I do not believe it to overstate the case when I note that from a formulary’s perspective, it was balancing along a knife’s edge.  That balance was lost minutely in mixing this batch of the polish, but that is all it took.

Here were the original goals, which Mel fulfilled brilliantly and deserves all of the credit and the Patents* that were issued.

  1.  The end product was archivally stable.
  2. The product was chemically benign regarding historic finishes.
  3. The product was physically benign regarding historic finishes; the product was easy to apply and bring to a high sheen.
  4. The product was very high performance for both the presentation of the object and its ongoing maintenance.
  5. The product was easily removed with no damage to the surface from the removal process.
  6. The production of the polish did not require exotic technology
  7. The product was safe for the user.

These features are not independent variables per se, no component of any formulation or application is separated from the others, but they are different conceptually and thus I will provide exposition on each one.

Archivally Stable

“Archival” is at best a vague word without objective quantifiable meaning, but for the sake of this discussion simply use it to mean that some material or composition of materials does not degrade unacceptably fast and that any degradation by-products do not become manifest as pernicious actors in the realm of deterioration.  That does not mean the word/concept has no utility when formulating a composition or even a practice.  For Mel’s Wax the ingredients and their proportions/mixing were chosen with great care, and selected for long-term stability.  This has pretty profound influence on the making and shelf-life of the product.  Though the primary ingredients of Mel’s Wax (the waxes themselves) have a half-life that is near-infinite within the context of recorded human history, others were selected for the longest possible half-life, such as the exotic emulsifiers.  And, the ingredients were selected with essentially zero cost consideration.  Think about an old favorite like Murphy’s Oil Soap, which retails for a few dollars a quart.  The emulsifiers used in Mel’s Wax, again, selected because of their stability vis-a-vie their degradation curve and chemical neutrality (see below) wholesales for *hundreds of dollars a liter.*

Chemically Benign to Historic Finishes

One of the truths of this particular cosmos is that the Law of Entropy cannot be repealed by even the most highly self-esteemed persons.  “Ashes to ashes dust to dust” is not merely funereal homily, it is an inexorable reality in a cosmos governed by the laws of thermodynamics.  So, as furniture finishes age they become closer to the “dirt” aspect of the verbiage just cited.  As a practical matter this means that historic surfaces and finishes become more chemically imbalanced over time (usually due to UV damage or the imbibing of oxygen) and thus more susceptible to chemicals that impart damage because the chemicals deposited on the surfaces are thermodynamically similar to the surface and will thus impart undue harm to the said surface.  This means that we have to maintain as close to a neutral balance or “polarity” for the chemical concoction being deposited on that surface.  This, in turn, affects the choice of ingredients to be the most benign possible, which in turn influences the procedures for making Mel’s Wax.  Those crazy expensive emulsifiers I mentioned earlier were selected specifically because they are less aggressive in creating the lotion-like polish, and thus less likely to inflict harm on  chemically fragile surface.  Further, the proportion of the emulsifiers in precisely calculated since excess emulsifier is a vector for accelerated chemical reactions, a/k/a “deterioration.”  Also, the selection of the organic solvents used in creating the  oil-and-water emulsion were selected for the maximum benign characteristics for aged surfaces.

Physically Benign to Historic Surfaces

There are some fine archival and chemically neutral furniture care polishes on the market in the form of paste waxes.  Unfortunately many of these products require sometimes aggressive rubbing of the surface to bring their applications to a conclusion.  Whenever you are faced with a physically delicate surface the last thing in the world you want to  do is rub it hard to burnish the maintenance coating (paste wax).  Given that reality based on what we knew it was pretty apparent that Mel’s Wax would need to be a creamy emulsion requiring very little physical impact on the surface for either application or completion.

High Performance

“High performance” is just another way of saying “It is physically robust and looks good.”  It is and it does.

Easily Removable

For long term preservation and care considerations any museum artifact maintenance product must be removable with the minimal physical or chemical impact on the sometimes fragile underlying surface.   Mel’s Wax was designed precisely to be removable with non-polar solvents and soft wipes like cotton swabs or lint-free felt.

Easily Produced

This was the point that precluded commercial-scale productions.  It is very fussy to make, in fact my experience is that it would be difficult to make in anything larger than a five-gallon batch; I normally make Mel’s Wax just over a gallon at a time.  The ingredients must be mixed precisely and with a fairly strict time frame.  Further, the thermal ramping (the rate of heating up and cooling down) is a real stinker.   Commercial enterprises, used to making home-care products in vats of several hundred gallons at a time, could simply not get it right.  Many companies tried, including some you might recognize; they all failed.  Instead the protocol Mel derived was a fussy micro-batch process that can go south with just a fraction of a percent of deviation.  In that regard it failed the “easy to produce” goal.

Safe to Use

Not incidental to the formulation design is that the end product would not only be benign for the artifact, it would be (comparatively) benign for the user.  Yes Mel’s Wax does contain organic solvents that are by definition deleterious to human consumption, but they are not acutely toxic compared to the overall landscape of industrial chemical engineering and formulation.  Eating or drinking it would end you up in the emergency room rather than the morgue.  As Dixie Lee Ray articulated in the Foreword to her brilliant book Trashing The Planet, under many situations di-hydrogen monoxide (water) is a lethal chemical.  Like, for example, if you were to experience extended, intimate and excusive exposure for more than a couple minutes, e.g. unmitigated complete submersion.  That would be a fatal incident.

Back to “The Cause”

This, my friends, is here the adventurous rabbit trail of solvent thermodynamics comes into play.  As I mentioned earlier the formulation for Mels Wax was a razor’s-edge situation; if any component of the manufacturing was off by just a smidge, whether ingredient, proportion or process, the delicate balance of the formulation would be undone, or at least modified from where it was supposed to end up.

And that is what happened, but not in the way I was expecting.  Solving the problem was an energizing exercise in synthetic thinking, combining the phenomenon (that which can be observed) with the noumenon (that which can be imagined).

When I was making this batch I was relying on my old faithful solvent, odorless mineral spirits, from the hardware store.  There is nothing wrong with generic or even common ingredients like this provided they are the same thing from the manufacturer every time.  I’d had great success with this particular solvent over the years.  However, this time when I opened the container and decanted the necessary amount of the solvent into the weighing vessel (the formula is designed to assemble the ingredients by weight, not volume) the solvent coming out of the container was the consistency of chunky sour milk (fortunately it was odorless).  Clearly some “shelf life” issue of the solvent and its plastic container was at work here.  I tossed all of that and cleaned up to move on to the next gallon jug.  Same thing.  Repeat and rinse.  Same thing.  And with that I was out of my trusty tried and true odorless mineral spirits.

No big deal, I just picked up some new solvent, from the same company to (supposedly) the same manufacturing specs, and proceeded as normal.  The solvent looked fine, the procedure went smoothly and I set about with other tasks until the polish gelled to the expected creamy lotion viscosity.

I came back in an hour and the polish had not gelled.  No reason for hysteria, it as a very warm day and the thermal ramping was just being petulant.  I came back in the morning and the gelling was still not to my satisfaction.  Hmm, what was going on here?  I even refrigerated one jar and it did not thicken to the desired viscosity.

At this point I stepped back from the entire episode for two weeks, just letting the stuff sit on the benchtop of the Waxerie while I cogitated.  After those fourteen days I revisited the batch of the polish and noticed something peculiar — there was a stratum of pure solvent at the top of every jar.  In a moment I knew what had happened.

The Crystal Set/Key-and-Lock Analogies – The Solubility Parameter

Have you ever wondered why substance A will dissolve in solvent X but not solvent Z?  That question is perhaps one of the very most important questions in coatings technology and you would be wise to contemplate it.  There is a real answer and I am going to tell it to you in a roundabout fashion.  Hey, it’s my blog and I can tell the story any way I want.  Hint -it all has to do with interatomic/intermolecular energy matching.

Stick with me now.

When I was a kid I got a crystal set radio, an earth-powered (actually it was the charge from the earth through the grounded radio chassis that made it work) primitive AM radio that allowed me to get the closest radio station to the house.  I would spend many evenings listening to that local radio station, and after dark when the locals went off the air I could tune in the station from the next town over.  Even though the crystal set had no power source I could listen to broadcast radio.  Why?  because the crystal of the crystal set allowed the unit to align, or match (receive), the frequency of the signal being broadcast with power being derived from the ground (I am not a radio engineer and did not stay in a Holiday Inn, so cut me some slack.  I’m trying to explain a concept, not enter the debate about Marconi vs Tesla vs. Edison).  Even with only the nearly unmeasurable electrons flowing through the crystal set it could “dissolve” the radio signals being broadcast because they were matched to each other.

Let me try another analogy.

Assume you come to visit me and my barn is locked (the punch line of my all time favorite joke is, “Assume a can opener.”).  Not to worry, you’ve got the biggest honkin’ key known to man in your pocket and you go after the lock on my door.  (I am assuming this action is done with my permission or you would have likely suffered a less beneficial outcome).  Is this going to work, are you going to get in?  Probably not. Why?  Because the configuration (the energy) of the key does not match the configuration (the energy) of the tumblers in the lock.

And that my friends is why the polish was soupy.  Let me explain.

The “solubility parameter” is the aggregate of (at least) three fractional components, which are in turn very specific intermolecular energy values. We use a graphical tool called the Teas Diagram to visually plot out the dissolving characteristics of both solvents and solutes, although this is an incomplete tool for selecting ingredients in a finish formulation. I discuss this at some length in A Period Finisher’s Manual.

The formula for Mel’s Wax depends on an organic solvent blend of a particular energy balance or “polarity” in order to walk the razor’s edge and fulfill all the preferences described above.  To work perfectly the energy holding the solvent blend together (the key) had to match the energy holding the ingredients together (the lock)  precisely —  not perfectly —  in order to accomplish the end point we wanted.  My old dominant solvent had the exact correct energies to match the ingredients were were putting into solution in this particular operation.  This phenomenon is called the “solubility parameter” as it is literally the aggregation of the interatomic and intermolecular electrical forces holding everything together, at least in the universe of solutes and solvents.   Often it is reduce to the verbal shorthand of “like dissolves like.”

Yes, there are solvents for Mel’s Wax that could do the dissolving more efficiently than others.  Solvent/solute compatibility is a range not a fixed point since no solute or solvent is 100% a pure single molecular content, and within one particular range we got the desired outcome.  Was this solvent blend the “perfect” one to create the solution?  No, because perfect solvation was not the preferred outcome since that “perfect” solvent blend would not fulfill the previously stated goals.  For that we needed a milder (less polar) solvent blend.  As I said the solubility parameter allows for a range of options to accomplish similar goals and characteristics.

Getting back to the original issue, why was this batch of polish soupy?  Because even though the new solvent as ostensibly identical or similar to the previous solvent (it was similar but not identical) and still well within the “safe” range or creating our archival polish, it was just enough different as to perform more efficiently as a solvent.  In short, each unit of solvent dissolved more of the polish ingredients than the previous solvent, so less of the new solvent was needed to accomplish the task of doing the dissolving.  In a normal solvent/solute solution this is usually no big deal, the solution is just a tiny bit more diluted than would otherwise be expected.  But, in a two phase system like an emulsion combining an oily fraction with a watery fraction even minute deviations can impart huge differences.

In the end, the polish was soupy because there was excess solvent that had nothing to do but sit around and be liquid adjacent to the two phase emulsion.  Yes I could force it to go into the emulsion but it would not stay there.  As I showed last time the performance of the polish was unaffected.  It was just soupy, that’s all.

But I didn’t want soupy so stay tuned for the next episode of As The Polish Turns to see how I responded to the problem.

Attending to Old Friends

Recently I had some time to spend working on a pair of early 18th Century Italian friends near Mordor.  As is almost always the case with wooden objects veneered with tortoiseshell, the delamination problem is never really solved as the wooden substrate and the mostly thermoset protein polymer veneer react to moisture changes at  different rates.  In this particular case that problem has been exacerbated in the distant past by the traditional housekeeping practice of slathering tortoiseshell with olive oil and linseed oil.   The practice is deleterious is every way, especially over time.

 

This time there were two sections of tortoiseshell that had become fully detached like this one, they were reattached with 192 g.w.s. hot animal hide glue after cleaning the substrate.

Then I worked my way around the mirror frames and identified a dozen places with delamination but not detachment and laid these back down after working glue underneath.

In the end I cleaned up the surfaces and applied a thin layer of Mel’s Wax over the surface.

I also documented the two dozen small losses on the frames; these are not detrimental per se and the client may want me to address these losses at some point in the future.

For now they are back up on the wall doing what they are supposed to do – look beautiful.  I no longer accept new clients, but expect to care for these old friends as long as I am abe.

This One’s A Head Scratcher

During a recent dive into my inventory of block planes needing restoration the lines of this one caught my eye.  It was comely, with a very low angle so I immediately thought it would be a good candidate for me to restore for my son-in-law.  Sure it was void of any adjusting controls but he knows how to adjust a plane manually with an iron-setting hammer.

At second glance there was something hinky going on with the plane.   Was the iron sitting in the pin?

Once I took it apart the confusion set in.  What the heck?  The way I read this tool, with the iron not resting over the pin but impaled on the pin, the iron is utterly and completely un-adjustable!  In one sense the tool is on the “primitive side” given the ostensible lack of mechanized adjustments.  Bur completely un-adjustable?  Given the general quality of the plane design and quality execution, I’m just left scratching my head.

 

At this point I’m noodling soldering on a block over the pin and using the tool as I first figured it was designed.  Or is the pin malleable and designed to be whacked back and forth with the iron?

Any thoughts?

Gragg Chair Cut List

As a general rule I think of “cut lists” as further indication of the inexorable decline of Western Civilization.  Still, one of the participants for next August’s “Making A Gragg Chair” workshop at the barn has asked me for a list of parts for the chair.  Since he is not likely to be the only one with interest, here goes (these are all nominal sizes, the finished elements are somewhat smaller):

long serpentine (2 pcs) – 1-1/8″ wide x 1/2″ thick x 50″ long

arm (2 pcs)- 1-1/4″ wide x 1/2″ thick x 36″ long

rear leg (2 pcs)- 1-1/8″ wide x 1″ thick x 23″ long

curved seat/back splat (5 pcs) – 1″ wide x 3/4″ thick x 32″ long *

short seat slats (6 pcs) – 3/4″ wide x 1″ thick x 14″ long

Crest rail (1 pc) – 2-1/4″ wide x 2-1/4″ thick x 19″ long **

Rear seat rail (1 pc) – 3-1/2″ wide x 3-1/2″ thick x 19″ long **

Front seat rail (1 pc) – 4″ wide x 1-3/4″ thick x 22″ long **

front stretcher (1 pc) – 1-1/2″ wide x 1/2″ thick x 21″ long

side and rear rungs (6 pcs) – 3/4″ oak dowel x 19″ long

*the center curved splat is widened by tapered glued elements at the top

** these are sculpted elements, not steam bent

Another thing I am working on is a set of full scale construction drawings for the students of the workshop.  If there is interest I could see about having them for sale in the Barn Store.  Stay tuned on that one.

 

 

Patternmaker’s Tool Kit Revisited

At first glance the patternmaker’s tool kit might seem nearly identical to that of the furniture maker.  Scribes, squares, dog-leg paring chisels, marking gauges (of which this kit had more than a half-dozen) etc., are identical even though their uses may be a bit different.  But the tools are the same.

Even their differences might be chalked up to meaningless peculiarities, but they are not.  Here is a brief review of some if those items unique to patternmaking, or uses of typical tools for particular applications.

Shrink Rules/Scales

Especially at the industrial scale resides the inescapable fact that molten metals shrink when they cool and solidify, and the degree of shrinkage depends on the metal alloy in question.  For this reason the patternmaker’s kit includes a variety of precision rules that take shrinkage into consideration, and when a new pattern is commissioned the drawings are transferred to a full-scale master made on a new piece of hardwood plywood with the dimensions established by the shrink scale.  In other words if the item being designed is to be 12″ long, in true measurement it would be 12 inches plus some fraction, but all of the scale delineations are created proportionally.  Thus when we were making  pump shell patterns for dredging operations, our main business, sometimes those patterns would measure 6, 8, or 10-feet in diameter (or even bigger).  When cast in grey iron the patterns for a 10-foot shell diameter were actually 10′ + 10/8ths inches in diameter (10′- 1-1/4″) since the shrink rate for iron is 1/8″ per foot of dimension.  This issue is rarely a fundamental consideration for the scale at which I cast these days.  For example when calculating the shrinkage on the Studley mallet bronze shell, with an overall dimension in the neighborhood of two inches given the shrink rate of bronze as 3/16″ per foot, the mallet shell casting would shrink 1/6th of 3/16″ or about 1/32″.  Even though I will use a shrink rule to lay out the pattern, I could probably get by without it.  Once I get done casting the mallet heads I will be moving on to patterns for the Studley piano maker’s vise, and that will be large enough to use the shrink rule for sure.

Dividers and Trammel Points

Dividers are critical for transferring the shrink-layout dimensions to the pattern itself.  This speaks to the importance of the master layout, usually executed on a pristine piece of hardwood plywood, as patternmakers realize and generally live by the ethos that “measuring is the enemy.”  If you get the master layout correct it is a regular routine to use dividers and trammel points to transfer and establish all dimensions for constructing the pattern from the layout.  In fact once the master layout is completed the only thing I can recall using the shrink rule for was when planing the laminar sections for stack laminated construction that was the norm when I worked in the trade.  I think it is pretty much a dead trade, nowadays everything is done with compewders and CNC/3D printing fabrication.

Beveling Gauges

Tapered angles are a huge part of a pattern, particularly in the tapers of edges that are more-or-less perpendicular to the parting line,  This bevel is known and “the draft” and to my knowledge always resided around the neighborhood of 2-degrees.  Thus a machinist’s combination square set with a protractor head was used almost every day, augmented with a bevel gauge for transferring the draft angle to the table saw and sanding machines (see below).  I probably used my protractor head with a 24″ rule more in one week at the pattern shop than in the 40 years since.

Sculpting Tools – Inside (Gouges and Draw Spoons)

Whenever a pattern shape has to be derived by handwork rather than lathe work, the two tool types employed for working the inside curves were gouges, of which there were a dozen or more in the full kit, and draw spoons, usually numbering a half dozen in graduate sizes.  The gouges are peculiar in that they have interchangeable handles, shanks, and heads, and usually made from high-chromium steel with very thin walls, and several are in-camber.  These are pushing tools, not striking tools.

If you have followed my work on Gragg chairs you have seen frequent use of draw spoons for working the swale of the seat deck.  They were used in a similar manner for working for the pattern shop as large, sweeping interior hollows were shaped delicately with the draw spoon.

Sculpting Tools – Outside (Spokeshaves)

Virtually all of the outside sculpting was accomplished with spokeshaves, seemingly undersized by furniture makers but capable of really hogging off material when necessary, or feathering a finished surface.  Patternmakers usually owned and used at least a half dozen brass spokeshaves.

Fillet Irons

Another truth about metal casting and shrinkage is that whenever two surfaces meet at a right angle or anything near, the crisp inside corner needs to be filled with a cove molding to soften the transition from one plane to the other, otherwise the casting will crack at that line.  In my experience this cove was established by shaped wax sticks, called fillets, which were purchased in bulk as literal cove moldings in wax.  I recall many, many hours carefully heating both the polished steel ball serving as the anvil, and the long wax sticks, then pressing the warmed wax molding into the inside corner using the fillet iron of the correct size.

This set of fillet irons even came with a scribed pattern block for making scrapers for each iron.

If it went well there was very little scraping afterwards to achieve a perfect inside corner, other times required some shaping with home made scrapers, one for each size of fillet.

Fillet Cutters

In the days before my time in the foundry fillets were cut from the edges of very thick pieces of leather using fillet cutters to create the roughly triangular fillet.  These tools would be pulled across the edge of the leather sheet, usually along a straightedge, resulting in a cove-ish strip of leather to use as the fillet.   These leather fillets were applied using glue and brads, and the whole assembly was finished by heavy burnishing with the fillet iron.  I never had to use this method but since I have a set of the cutters and live in cattle country, come the zombie apocalypse I will be ready.

 

 

 

 

Core Box Planes

In the Golden Age of Foundries there was probably no bigger component of the industry than that of making pipes.  Think about the civic infrastructure whether on a single building scale or a national scale.  It was all made from or connected with pipes or pipe-like elements.  Making an outside sand mold to cast pipe-ish shapes is no big deal, all the expertise was applied to the problem of making a sand mold “core” to establish the cylindrical hollow insides.  For that process a special “core box” had to be made for each unique casting.  Often the shape of the box was achieved with core box planes, of which there were many varieties.

 

Some looked more akin to a set of hollows-and-rounds,

 

others were similar to the H&R set but instead of full body planes they had a single body with interchangeable soles and irons,

and undoubtedly the weirdest ones were metal frames with notched outriggers to ride on the outside of the core box and were equipped with ratcheting rotating cutting arms that advanced a few degrees around the compass to complete the half-core.  Oh, and these mechanical core box planes looked suspiciously like a Klingon warship.  There is yet a fourth version that is essentially a right-angle sole bisected by the iron, but I do not own one of those.  NB –  metal casting of almost any kind involves core box work regardless of the shape so long as the casting has a hollow configuration.

 

Power Tools and Accessories

Patternmaking since the mid-1800s has employed a variety of machines for fundamental work.  Included were power planers (I just use my lunchbox planer but if I did lots of patterns I would get my Mini-Max 14″ combination machine up and running) that could quickly and precisely dimension stock to the peculiar measurements required especially for stack laminated patterns, tables saws, disc sanders and oscillating spindle sanders to allow working to the middle of a cut-scribed layout line at a precise bevel angle usually 2-degrees.

If you follow my trek down the metalcasting road you will see all of these tools demonstrated over time.  Well, maybe not the core box planes as I have little intention of casting large pieces of iron pipe.

Stay tuned.

PS  I was wondering if I should make a start-to-finish video on metal casting, but I gotta get the Gragg video done first.