Finishing

Summer 2019 Workshops at the Barn

I have settled on the topics and approximate schedule for next summer’s classes here in the hinterlands, with three of the four classes emphasizing toolmaking.  I will post about them in greater detail in the near future.  One minor change I’ll be instituting next year is that three-day workshops will now be Thursday-Friday-Saturday rather than Friday-Saturday-Sunday as before.

June’s class will be a metalworking event, Making A Nested Set of Roubo’s Squares.   The objective will be for each attendee to create a set of four or five solid brass footed squares, the sort illustrated in Roubo’s Plate 308, Figure 2.  The special emphasis will be on silver soldering, a transforming skill for the toolmaker’s shop.  The tentative dates for this are June 6-8 or 20-22, $375 + $25 for materials.

July’s class will be my annual offering of Historic Wood Finishing.  Each participant will complete a series of exercises I have devised for the most efficient learning experience to overcome finishing fears and difficulties.  Of particular importance are the aspects of surface preparation and the use and application of wax and spirit varnish finishes using the techniques of the 1700s.  Probably July 11-13, $375.

In August we will continue the pursuit of Roubo’s tool kit, this time Making and Using Roubo’s Shoulder Knife.  I have no way to know exactly how prevalent was this tool’s use in ancient days, but I suspect more than I can imagine.  Each participant will fabricate a shoulder knife to fit their own torso, so its use can be both the most comfortable and the most effective.  Probably August 15-17, $375.

The final class for the year will be a week-long Build A Ripple Molding Cutter.  As I have been pursuing this topic and blogging about it, fellow ripple-ista John Hurn and I have settled on a compact design we think can be built by every attendee in a five-day session.  Together we will be teaching the process of ripple moldings and fabricating the machines that make them.  September 23-27, $750 plus $200 materials fee.

Save the dates and drop me a line for more information.

Writing Desk – Polishing and Assembly

Once the finishing process was essentially complete it was time to rub out the surfaces and glue-up the desk.  Since my goal for the surface was to present an unfilled, lightly-worn, ancient-but-well-cared-for appearance and character I rubbed down all the surfaces to accomplish those ends.

My typical procedure for this undertaking is to abrade the surface with ultra-fine steel wool saturated with paste wax or conversely a 4F pumice/paste wax blend, incorporating or succeeded by the inclusion of tripoli/rottenstone to leave subtle traces of “ancient schmutz” in the crevices.

In this instance I mixed up a paste wax/rottenstone blend to use with the steel wool, and proceeded to rub every exposed surface until the outcome arrived at the destination I was aiming for.

The “glow” and subtle grain of the resultant surface was so glorious I had to just look at it for a while.

This comparison of a rubbed-out (L) vs. raw surface (R) is demonstrative of the transformation.

This is the address I was looking for.

With the finishing mostly done I glued everything together with hide glue, and suddenly there was a complete piece of furniture staring me straight in the eye.  There were only a couple of final steps to take, applying another round of pad finishing to the writing surface before rubbing that out, and buffing off the rottenstone-laced dried paste wax.

Writing Desk Finishing – Color and Craqueleur

With the desk surfaces well-sealed with lemon shellac and the finish foundation built up with garnet shellac it was time to wrap up the color work while simultaneously imparting the craqueleur that would reside under the final, polished surface imparting the “look” of an ancient but well-cared-for surface.  The process was simple, one that I have employed before and takes advantage of the properties of the materials found on the shelves of finishing shops.  Well, at least on the shelves of my finishing shop.

As I have written previously I am loathe to contaminate the raw wood with colorant that cannot be easily removed.  Hence my distaste for pigmented “stains,” dyes, or chemical treatments.  I find these techniques to be insufficiently control-able for precision finishing, preferring instead to introduce any coloration into the finish system itself.  Not only is this much more easily controlled but comparatively effortless to undo if the target is missed.

My common terms for this kind of in-finish coloration is “toning” if the coloration is included in the film forming material itself (i.e. the varnish), or “glazing” if the coloration is imparted via a discrete material in-between coats of finish.  In this project I was able to blur the lines in these concepts and add an additional feature to arrive precisely where I wanted to go.

In short, my goal was to provide visual unity of both the color/tone and impart richness to the texture to replicate a finish that gave the appearance of being well-cared-for but 200 years old.  It was not to be a grain filled, brilliantly glistening “French” polished surface, that was simply not appropriate for this project.  I wanted the surface texture to be presented subtly for both the wood grain and the cobwebbed craqueleur within the finish film itself.

Here is a brief recitation of the technique I used to accomplish this.  It depended on understanding the nature of materials and their means of forming films (or not).  There was no magic elixir, but rather an exploitation of those materials.

I began with my glaze formulation, which first consisted of solid acrylic resin beads dissolved in hot mineral spirits to a 25% solids content.  This served as the backbone for the glazing solution and the governor for my desired solvation limits that in turn controlled the craqueleur.

To this I added some oil/resin varnish in the proportion of 1 part acrylic resin solution to 3 parts of varnish, followed by stirring in asphalt as the primary chocolate-y brown colorant and a dab of sienna artists’ oil paint to get the right amount of reddishness, thinned as needed with naphtha.

I slathered this on to the surfaces that had been well-built-up with the shellac base.  The glaze was evenly distributed with a well-worn vintage (and thus soft-ish) bristle brush, pulling off glaze in places where it was imparting too much unnecessary coloration, smoothing it out where the color was correct.

The final step was to soften any striations by whisking the surface with a badger blender or goat hair hak-e brush just before the glaze dried too much to be manipulated further.  The entire process for a particular work area from slather to done was probably about 90 seconds.  This was then allowed to dry overnight.

The next morning to lock it all in place I spritzed it with a light coating of sprayed shellac.  This resulting surface might have sent an inexperienced finisher screaming for the hills but I had a huge smile on my face because the result was exactly what I wanted to achieve.

Let me explain.

The oil-resin varnish and artists’ paint in the glaze had stiffened but were not yet fully hardened, so the introduction of of a more polar solvent (in this case alcohol in the sprayed shellac) to the glaze would cause the glaze film to become imbibed with the solvent, swelling the polymer matrix into a crinkled texture.  On the other hand, since the acrylic resin and asphalt are not susceptible to the same solvation effect they remained calm, otherwise the surface would not have been a variegated craqueleur, it would have been velour.  And, with the glaze film being ultra thin yet bonded to the underlying shellac via the adhesive properties of the acrylic resin component I did not have to worry about the whole laminar construct coming apart.

(NB – I discuss all these properties and effects much more thoroughly in my upcoming book, A Period Finisher’s Manual).

I waited another day to make sure the solvent from the shellac mist coat had diminished sufficiently and abraded the surface very lightly before building more finish.  At this point my main concern was adding too much additional alcohol to the system and causing even more oil/resin film swelling, so rather than brushing on shellac to build the finish I padded it on.  Remember, my goal was not a glistening pad-polished presentation surface.  I padded the finish simply because it was the best way for me to deposit film-forming material while controlling the solvent encroachment.

After enough new finish was added on top of the craqueleur, three applications as I recall, I abraded the entire surface smooth, in essence leaving the craqueleur embedded down in the finish but still presenting a smooth surface that I could polish out.  I built up another half dozen padded applications to the writing surface after the piece was assembled then set it aside for a fortnight before final polishing, assembly and detailing.  As you might surmise the craqueleur was so subtle it was impossible for me to photograph.  It has to be observed in real time and in real space.

It is worth remembering the beginning point for all this color work.

Now it was time for the polishing, assembly and detailing.

Stay tuned.

 

 

 

 

Desk Finishing – I

With the construction finally completed it was time to dive into the part of the project that had no down side, the part where it was all fun all of the time — finishing.  In my back-and-forth with the client I decided to shoot for a non-filled-grain look, a general tonal consistency, and with craqueleure underneath the the final surface.  In short my overall strategy for the process was to have the desk looking like it was “old but well-cared-for,” looking new was not part of the plan, nor was “antiquing” nor “distressing.”

Since the desk was small and convoluted I intended to finished almost all of the pieces prior to final glue-up.  So the full glory of it was not revealed until nearly the last step when all the pieces were put together.  Finishing each piece separately required a careful masking of all the surfaces that were glued together in that assembly.

The first step was to lay down a few seal coats of garnet shellac brushed on in three or four applications of a one pound cut.  This allowed me to get a good sense of how I needed to shift the visual coloration and tone of the pieces to bring them into harmony.  I would make no attempt to make each and every piece identical to the other, that was nonsensical given the variety of grain directions, etc. involved, but simply to bring everything closer en suite.

For the most part the starting point for this shifting was accomplished via the addition of dyes to the garnet shellac being brushed on.  I am loathe to employ chemical stains to bare wood as part of the finishing exercise; they are simply too difficult to control for an equal outcome when the starting points are different, and when they do not behave their reversal (removing the surface of all the wood) induces foul language in the shop.

By building the finish with dyed coatings the depth of the wood’s beauty soon emerged forcefully.

I built the finish steadily, five coats becoming ten, then fifteen.  I smoothed all of the flat surfaces by scraping with razor blades and the curved surfaces with pumice pads and before long I was ready for the home stretch.

But the real magic of final blending of the coloration, along with imparting craqueleure, was achieved in the next step.

Stay tuned.

Guest Post — On Cotton And Linen Rags

A requested piece from my long time friend and collaborator Michele Pagan, a textilian as long as I’ve been a woodworker.  — DCW

Knowing that good rags are a foundational tool for the woodfinishing shop,  my good friend and colleague, Don Williams, invited me  to provide some comments regarding the characteristics of cotton and linen, both plant materials, for the woodworking community.  I am delighted to share my decades of experience in the subject with you, and appreciate Don’s invitation.

If you are a savvy, practical shopper, as I know Don and I both are, you might look for pieces of cotton and linen in your local thrift store, or maybe even an antique shop. Pieces which are possibly already damaged are a very good idea, if your intent is to cut them up into smaller pieces, anyway, to use in various aspects of woodworking and maybe conservation.

Don’t be confused by labels that declare “Table Linens” or “Bed linens” – those are just generic terms which say nothing about whether the table napkins you are considering are actually made of linen. You could find genuine linen in the men’s shirt department – garments always include a fiber content label, which is very helpful in this case. My favorite thing to do is buy cotton flannel sheets, and then use them as table covering in my textile studio.

It’s not always obvious whether you are holding a piece of cotton or linen, for 3 main structural reasons: every fabric has a fiber, a weave structure, and a finish.

All together they can make cotton look like linen, and vice versa. Let’s look at each of these factors sequentially:

First the fiber, and maybe these 2 photographs will help illustrate the difference:

Cotton fiber, cross-section and longitudinal.

Flax cross-section and longitudinal view.

Cotton fiber under the microscope resembles a slightly twisted ribbon – which creates a softer, pliable surface texture. It also allows cotton to absorb a great deal of moisture, and this makes cotton stronger when wet, than when it is dry. Just try to rip apart a piece of wet cotton fabric!

Linen, on the other hand, resembles stalks of bamboo,  stiff  with crosswise nodes. It is because of this more orderly and stiff  structure that linen is stronger than cotton – not terribly much so, but stronger. The strongest of all fibers is nylon, these days used commonly as one of the microfibers – but that is another topic for another day, or blog!

In fact, this chart shows you the abrasion resistance of many of today’s fibers.  As you can see, there are many synthetic fibers which are stronger than either of the 2 cellulosics that we are discussing, but for our purposes, let’s just focus on flax (from which linen fabric is made) and  the slightly less resistant to abrasion fiber, cotton.

In fact, the most basic test you can do – admittedly, not while you are in the store, though – is to place a drop of water on the surface of your used fabric. With linen, you can literally watch the water travel sideways down the length of the yarn.inally, let’s talk about the finish on the surface of any fabric. This is the final step in fabric manufacture, which gives it the beauty which is so desirable.

Normally, linen has a shinier, heavier feel than cotton. It has a nicer “hand” we say. Even though it gets wrinkled just as much as cotton,  it has a more elegant drape to it and just feels heavier. Admittedly, this is an acquired skill – feeling the additional weight of linen vs cotton.

And… this is where finishes come in.  Finishes can be added to cotton to make them appear shinier and smoother than linen, but often these finishes wash out. Certainly with cottons that are bought at antique and thrift shops, the finish may be completely gone. I’m thinking of fabrics like Polished Cotton, or even chintz, which are achieved by the addition of a shiny finish to the top surface of the cotton fabric.

Here’s a very good website, with reasonable prices, in case you just really need to order exactly what you need, rather than trying your luck at the local thrift shop.

 

Woodfinishing Workshop – Day 3

The final day of my finishing workshop is all about the final appearance, including rubbing out and adjusting color the shellacked big panel, which had more than a dozen coats and looked like this at the start of the day.

Beginning with the 24×48 panel subdivided into quadrants, each received a different treatment.  One quadrant was left untouched as a reference point, then work began on the second one.  It was rubbed with Liberon 0000 steel wool, then rubbed with more Liberon 0000 infused with paste wax.  The result is wondrous, and this is one of my very favorite finishes.  It glows visually and is irresistible for just rubbing your fingers over its surface.

The third quadrant was polished with tripoli/rottenstone and mineral spirits, using a fine linen polishing pad nearly identical to that used for spirit varnish pad polishing.   Any residue was wiped off and the surface received a light coat of paste wax.  The resulting surface is absolutely spectacular.

The fourth section was rubbed with dry Liberon 0000 to give it a tiny bit of tooth for the addition of colorant glazing.  Two gazes were tried, the first being asphaltum thinned with naphtha and the second being waterborne shellac with goauche colorant.  They work very differently but both students had excellent results of a gentle color shift.  The final step was to seal the glazing with a brush coat which both saturates the color and provides an even gloss.

The final project completed was rubbing out and waxing the raised panel doors and the table legs.

We took pictures of their gallery of work, and they headed for home.  Both had very long drives, one to Louisville and the other to Syracuse.

Historic Woodfinishing Workshop Day 2

The primary work of Day 2 was building up the finishes in preparation for the rubbing-out and toning of the final day.

The first task was to scrape the large shellacked panels with disposable razor blades to get them smooth as silk for the final application session to follow.  True enough, disposable razor blades are not historically precise but scraping is, and using the disposable blades is the best way I can get the process integrated into the workshop.  If done carefully the resulting surface is pretty much a flawless ground for the final layers of varnish.

We then moved on to some tables legs to get a little time in on working with “in the round” components.  These are often a challenge for inexperienced and old-time finishers alike, but one key to success in this regard is a light touch and the right brush.  I’ve found that a rounded-tip brush, sometimes called a “Filbert mop” with good bristle drape results in a near-perfect application every time.

The fellows worked so fast we had time to insert a couple of exercises, one being the use of molten wax on tables legs.  We let a hair dryer substitute for a red-hot poker, but the results were acceptable.

Raised panel doors are also a sometime headache, but once you get the hang of the routine it works out pretty well.

Finally it was time to start on the spirit varnish pad polishing, a/k/a “French” polishing.  Each of the students constructed their own pad from cotton wadding, then charged it with the spirit varnish.  (This led to a fairly involved discussion about the fabrics that are best suited for which tasks in the finishing room.  I asked my long time friend and Roubo colleague Michele Pagan, a textilian for as long as I have been a woodfinisher, to write a blog post on the topic.  I will post it probably next week.)

By tapping it on their palm they knew when it was ready to go.  And, it gives a lovely sheen to the palm.

The boards they had prepared on Day 1 were partially wax-filled and partially raw-but-burnished wood.  Since so much of spirit varnish polishing is “feel” there was not much to do but turn them loose.

Before long there was a-glist’nin’ all over the place.

Another exercise that frankly I have never been able to get perfect was to fill the grain with beeswax and powdered colorant, pressed in to the wood grain with a polissoir.  I need to work on this concept a little more, although Roubo promises success.

And with that we were done with Day 2.

Historic Woodfinishing Workshop Day 1

Recently I hosted my almost-annual three-day Historic Woodfinishing workshop at The Barn.  Due to family medical emergencies three of the five registrants were unable to attend.  This, combined with some seasonably chilly weather (holding this the final weekend of April was an experiment that will not be replicated), led me to relocate the event into my heated workshop rather than the unheated classroom space.  That actually added to the intimate atmosphere of the session.

My syllabus for this workshop is pretty well established after this many iterations.  Given the brevity of the schedule I restrict it to only two major finish materials, shellac and wax.  Next year I am penciled in to teach a longer workshop at MASW so we can explore the topic more broadly, but for now this is what we cover.  As always my objectives are to 1) present finishing as a structured enterprise, to familiarize the participants with my approach to finishing and remove any hurdles of intimidation, and 2) provide some hands-on/muscle memory experiences to impart confidence for once they are back home.

One of the foundational exercises is to brush shellac spirit varnish on a 24″ x 48″ plywood panel that is straight from the bin at the lumber yard with only the most cursory preparations of sanding with 220 paper for a coupe minutes.  The objective is to build up enough finish in three sessions, two on Day 1 and one on Day 2, to provide a great base or polishing out on Day 3.  Each of the three sessions results in about a half dozen applications of varnish.  In between the first two application sessions on Day 1, the dried varnish is lightly rubbed with dry pumice to remove and nits that are there.

Other Day 1 exercises include burnishing a mahogany panel with a polissoir, with a polissoir and wax, and applying a layer of molten wax to fill the grain and serve as a final coating.

Thus endeth Day 1.  Now on to Day 2.

Matching Appearance

For the final session of the SAPFM Tidewater Chapter Spring Meeting I was asked to talk about “matching color” but I took the liberty of broadening the topic to “matching appearance” which I think is more useful.  Though my demonstration component did indeed focus on understanding the perception of color and its modification, it occurred within the larger context of “appearance.”  Normally this is a topic I like to spend a week covering, so in 90 minutes I barely got to the highlights.  In fact, at this fairly late date I have decided to add a full chapter on the topic to my Period Finisher’s Manual book for Lost Art Press.

There are many aspects of appearance of interest to woodfinishing and I addressed each and their interrelation briefly.  One point I made repeatedly is that if matching color is a critical component of any projects, that must be accomplished in the finishing layers (or between them), NOT in staining the wood.

 

Trying to match any color via the manipulation of wood stain on the bare wood surface is a fool’s errand.  To get to where you want to go, you must know where you are starting.  And that means the wood surface must be sized with enough coating to establish the base appearance and color.

There are times where the selection of the coating itself is a critical component of achieving a specified color.

Once you get to the point of manipulating the coloration, I believe that the traditional color wheel is inadequate to the task.  Instead I prefer a different conceptual model for color, and that model is known as the “L,a,b” color system.  I will not go into detail here as to how I use this system in my own color work, suffice to say it is functionally a subtractive system i.e., if something is too red, I add green, if it is too yellow I add blue, to neutralize the excess color.

Adding tonality to the surface appearance can be achieved through tinting the coating itself with dyes or pigments.  Here I am using some very intense organometallic synthetic dyes that were originally created for industrial and automotive paints, if I recall correctly.  These are  Orasol dyes and have a somewhat peculiar palette to select from, and are available to the finishing trade at Olde Mill.

The means of imparting coloration are many, and once again I only use color in or in-between the finish.  One of the simplest and most effective techniques — and historically accurate to boot — is a light glaze of asphaltum.

And speaking of glazing, I spoke for a few minutes about how to determine whether or not you have good glazing brushes.

Another glazing technique I demonstrated was using artists’ watercolor paints known as goauche with a waterborne shellac binder that I made right there in the meeting.  If you do not get the color or tonality correct, just wipe it off with a damp rag and start over again.  You have perhaps a half hour to do this before the waterborne shellac sets, and it is very tenacious once dry.

And then it was time for everyone to go home.

Always On The Lookout #2

Recently while en route to the SAPFM Tidewater Chapter meeting I stopped into a Michael’s store in search of one ingredient I wanted for my demonstration.   They did not have what I wanted but as is my habit I took a stroll through the art supplies to see what might be on sale.  My mouth probably fell open as I saw a deep discount on all their inventory of Robert Simmons Sapphire brushes, the sable/nylon blend bristles that for me are the standard by which all others were measured.

They did not have any 1″ brushes, but I bought all the 3/4″ flat wash and filbert mops they had.  In doing so I added another half-dozen to my inventory (since I do so much teaching of finishing, I can never have enough good brushes), saving myself a ton of money.  If I recall correctly these brushes are listed at about $70 apiece at retail, and I got these for about $10-12 each.

I do not know if this is a discount at Michael’s nationwide or if this was restricted to the one store I was at, but it would be worth your checking it out.

UPDATE:  I’ve been to several Michael’s stores and found each of them to have the same discounted offer.  They didn’t all have any inventory, but they all had the same discount.