Finishing

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.

Stripping Spindles Efficiently

One of the exercises I incorporate into the syllabus for the Historic Finishing workshop is finishing a baluster spindle or two, to get the feel for brushing finish onto an undulating surface.  Rather than spend a lot of time finding new ones for student use I just got a trash can full of them and recycle them as necessary.  I found a very efficient way to strip them in preparing for the next round of use, a solution that I think would work for anyone who has a similar task.

I had our local welding shop to fabricate two vertical stripping tanks (for about $80), comprised of a piece of steel pipe welded to a steel plate base.  One of my standing tanks uses a 2″ pipe, the other 2-1/2″.  This allows me to use (and lose) a minimal amount of whatever solvent I am using, whether paint remover for the initial treatment of painted spindles or denatured alcohol for recycling the shellacked ones.

The system works like a charm, I just put the spindle in the pipe and fill it with solvent, then place a piece of metal plate on top to hold the spindle down and cap the cylinder, and in a few minutes I extract the stripped spindle, allow excess solvent to drip off, and wipe it down with paper towels  It literally takes only 15-30 seconds of my time to get one done.  Over a few days’ of doing this I lose only about a half-pint of solvent to evaporation, and whatever additional solvent is absorbed into the film.

Always On The Lookout

 

While preparing for the upcoming “Historic Finishing” workshop at The Barn the last weekend of this month I was struck by my good fortune in acquiring an excellent inventory of vintage finishing rags.  This pile was particularly peculiar as it came from an antique shop twenty miles from town, out in the prairie of Nebraska.  The main emphasis for the establishment was rural and agricultural collectibles, but in my browsing I came across a large box of muslin feed sacks.  These had been carefully — almost lovingly — washed and folded, and were in astonishing condition.  No holes, no stains, and a wonderful nap of both sturdiness and suppleness.  In short, perfect for the finishing shop.

I bought the entire pile of these wondrous rags, I think for about 20 dollars. There were about 60 complete feed/seed bags in the box, which means a price of 33 cents apiece.  I’ve seen similar items going for up to $10 at shi-shi antique boutigues (seriously who “decorates” with feed sacks?).

Students in the upcoming workshop will get to give them a test drive as each will make several polishing pads, some for applying spirit varnish, some for abrasion polishing with pumice and tripoli.

So always be on the lookout.  You just never know when you might come across a box of treasure.

2018 Barn Courses Fortnightly Reminder

The complete 2018 Barn workshop schedule, which I will post every couple of weeks to help folks remember the schedule.

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Historic Finishing  April 26-28, $375

Making A Petite Dovetail Saw June 8-10, $400

Boullework Marquetry  July 13-15, $375

Knotwork Banding Inlay  August 10-12, $375

Build A Classic Workbench  September 3-7, $950

contact me here if you are interested in any of these workshops.

Cool Pic

I set my bottle of padding varnish (1/2 pound cut of Lemon shellac) up in the window sill over the finishing bench, and did not return to it for many moons.  I thought it was pretty cool to see how, left undisturbed, gravity had separated out the fractions of this natural heterogeneous exudate in solution.  The clarity of the fully solublized wax-free fraction on top is a nice contrast to the partially solublized and suspended wax-containing fractions on the bottom.

Shellac: adhesive, varnish, dyestuff, condiment, pharmaceutical ingredient, cosmetic, pyrotechnic binder, and now, entertainment source.  Is there anything it cannot do?