I began my interest in French Polishing several years ago after hearing a lecture by Eugene Clark. Mr. Clark is one of the foremost experts on French Polishing in the guitar making world and I was fascinated by the ancient techniques and materials he used, as well the extraordinary results he obtained. I subsequently was able to attend a workshop with Mr. Clark and study a couple magazine articles about his methods.
In addition to my own initial experiments with French Polish, I read several modern finishing books which typically include a chapter on French Polishing. While several of these books are competent in their descriptions of the process, I was dissatisfied with their modern approach to a decidedly non-modern finishing method. I began to read and obtain old books and articles about finishing. However, I found that even works written in the '30s described French Polishing as an archaic method no longer much used.
I attempted to obtain late 19th and early 20th century works on the subject. While no one book that I've yet discovered was definitive, each seemed to have a morsel or two of information I found useful. What I also found interesting was that each book described the process of French Polishing very differently, using various resins, polishing materials, and methods of procedure. I came to the conclusion that rather than be confused by various methods, the fact that different craftsmen got good results from divergent methods was proof of the strength of shellac finishing in general and French Polishing specifically.
The materials, techniques and methodologies I will describe are therefore the ones I use and not necessarily the ones you should use. I will try to point out things that I view as absolutes, as well as some methods that others use, even if they are not my own. In the final analysis, experimenting with shellac and French Polishing can be fun, and you will no doubt discover techniques that work best for you. I should also point out that since I am a guitarmaker the methods I use are geared toward musical instruments, though they will work equally well for polishing other items.
So while the entire finishing world has turned away from this traditional method what are its benefits and why should you try it? Here are my reasons (in no particular order of importance).
- Beauty: It is still hard or perhaps impossible to beat the natural beauty of a French Polished piece. A gloss nearly as high as nitrocellulose lacquer can be obtained with a more natural, less plastic look. The depth and character of a French Polished work is unsurpassed. Expertly polished work appears as if you can see each individual cell of the wood.
- Thin Build: A very glossy finish can be obtained with a relatively thin build of finish, a particularly important issue for instrument makers. You don't have to slather the stuff on to get a superior result.
- Longevity: With reasonable care, a French Polished finish will last and look beautiful for a very long time. French Polish ages and darkens gracefully, unlike the cracking and yellowing of nitro lacquer, for example. A properly prepared piece will become an heirloom for generations to come.
- Ease of Repair: Shellac is one of the easiest finishes to revive. An old finish, unless seriously damaged can be revived by spiriting off (I'll describe that later) or by the addition of more French Polish.
- Durability: Don't let the naysayers fool you. Shellac finishes can be made very hard and durable and resistant to elements that supposedly ruin them. In addition, shellac's natural elasticity allows it to "breathe" as the wood moves, resisting the cracking of some other finishes.
Debunking the Rumors:
Rumors of French Polishing's demise have been greatly exaggerated. The following are typical criticisms of French Polish with answers which I hope you will discover for yourself.
- Water Damages It: I have heard people report of polished finishes where they spilled a few drops of water and by the time they wiped it off with a cloth, the finish was damaged. Something was wrong with that finish, folks. French Polished finishes can be made highly resistent to water's effects. Not that you'd want to finish your outdoor furniture with shellac, but I'll show you how to make your finish more than adequate for most requirements.
Don't believe it? Try this. Put a few shellac flakes in a glass of water and let it stand. What will happen? The shellac will not bloom. Its highly water resistent. When you think about what its used for in nature it had better be! And while we're trying to abuse shellac, Eugene Clark also showed us how to hammer shellac. Really! Hammer a few shellac flakes. Of course they will break, but they will not powder white. Shellac's a remarkable resin.
So how come French Polish has the reputation of being so easily damaged by water? If it ain't the shellac, it must be other materials used in the process.
A quick story: The first piece of furniture I French Polished was an old end table I have. Little more than a piece of junk, really. Some parts of the finish turned out OK and some didn't. Nonetheless, I put it back in my living room. My then two year old son always loved to spray water with a squirt bottle. He often sprayed that table with his water spray bottle and then wiped it with a towel. Of course at two he only got about half the water off and it tended to sit there on the table's surface for hours. The water never damaged the finish. The finish is still in the same condition (mediocre) as when I first polished it!
- Easy to Scratch: At least that's what some people say about French Polished finishes. The first time I saw Mr. Clark's presentation he passed around some tools whose handles he'd polished. Surreptitiously I tried to scratch the finish of one with my thumb nail. I couldn't. The finish was plenty hard all right.
- Takes Great Expertise to Produce a Good Finish: Nonsense! Of course, like anything else, more experience will produce a better result, but this is truly not a difficult process. You don't have to devote your life to it.
- It Takes a Long Time to Do: OK, there you've got me! French Polishing is more labor intensive than modern finishing methods. This is in truth the reason that furniture makers went away from French Polishing late in the 19th century.
In addition to taking time, French Polishing must also be done by human hand. Think they only tried to develop labor saving devices in this modern, plastic, slapdash era? Think again. About a century ago, an enterprising furniture maker created a machine which could hold a polishing pad and recreate the circular motions of the French Polisher. In addition, the machine automatically fed polish to the pad at regular intervals. So the guy made a fortune, right? Nope. The machine failed because French Polishing requires a human hand, eye and brain to make the minute adjustments a machine cannot.
What is French Polishing?:
French Polishing has been called a true one-step finishing process. Of course, there are steps to French Polishing, but it is the only finishing system where the polisher may be filling, bodying, and spiriting off a piece simultaneously, using the same materials! French Polishing is a process, not a product. Most of it is performed using the same materials, but the experienced French Polisher varies functions by varying the ways he uses the materials.MATERIALS
Shellac:
Here's one of the few "must dos" in French Polishing. Only use shellac flakes (and the best ones you can get). While many of the pre-prepared French Polishes and shellacs no doubt are fine products for general finishing purposes, one of the major advantages of traditional French Polishing is the control you have over your materials. So use the raw materials and prepare your own polish.
By the way, while blond and super blond shellacs are the staples of most polishers, don't be afraid of experimenting with other colors of dewaxed shellac. I typically mix my colors to get the shade I want. This again allows you to have much greater control over your process than a pre-mixed product would. You may even get to the point where you will want to dewax some of the darker shellac colors.
Alcohol:
I've heard so many theories about what works best that my head spins. I use good old hardware store denatured alcohol with excellent results. I've heard good things about Behlen's Behkol, but its much more expensive.
Oils:
Some French Polishers do not use oils in their process, but most do. The use of oils has 2 potential benefits: lubrication of the pad when applied to wood; and creating a harder finish by using a drying oil.
Traditionally many polishers used raw linseed oil as their drying oil. Most polishers today have gone away from it. Raw linseed oil can polymerize and can actually completely fail over a number of years, the varnish turning sticky and gelatinous.
The other traditional oils used were vegetable oils. I use walnut oil as my drying oil and olive oil for lubrication.
Make sure you use 100% walnut oil. The Hain brand used to be pure, however it now includes vitamin E, an antioxidant. The Spectrum brand is good, as are others.
Mixing walnut oil into a shellac varnish creates a temporary dispersion, allowing more oil to be combined into the body coat. I typically use a 2 lb. cut for my shellac and add 2 or 3 tablespoons of walnut oil. Don't worry too much about exact measurements. The shellac will use what walnut oil it needs and throw off the rest.
By the way after you've completed polishing your workpiece, the finish will continue to harden for a very long time (a year) so don't expect it to resist scratches immediately. My understanding is that walnut oil works like some of those "cross-linking" modern finishes. It will continue to harden for quite awhile.
As for olive oil, just use a basic olive oil like you'd use in cooking. I know of no particular advantage between brands.
Pumice:
While not used by all French Polishers, the use of pumice is very traditional and is referred to or recommended in most references. For me, the use of pumice represents what is most incredible about French Polishing: that is that its primary components are used for so many things. Pumice is used as a grain filler early on in the process. Many polishers use it periodically when putting on the body coat to smooth the finish as they go along, as well as fill any pesky imperfections/pores that still are visible.
At one time pumice came in many grades. Today, Behlen's markets it in 2F and 4F versions (4F is finer gritted). While I don't understand the process of refining pumice, the F means "floated": 2F is double floated, 3F triple floated, etc. For all practical purposes the grade of pumice isn't too important in filling, though I use 4F pumice later in my French polishing process, since I don't want to use something too abrasive at that point.
While other materials were at times used to fill open pored wood (plaster of paris, for example), pumice is generally considered the best. When filling (I will detail this later) the polisher combines polish, oil and pumice on the pad. The pumice abrades the wood (which at this point is only covered by a light sealer coat) creating wood dust. The combination of polish, wood dust, shellac dust, and pumice is forced into the pores. A great system since you don't have to worry about color matching - you're using the dust of the wood itself!
Pad/Fad/Rubber:
"You say fad, I say pad. Let's call the whole thing off..."Different references refer to that with which you apply the finish by several names. While there seems to be no universal agreement, here's what I believe to be true.
A rubber refers to an applicator with an inner pad surrounded by an outer cloth. Each polisher seems to have his/her favorite materials, which they all swear to. Most agree that the inner pad should be absorbent material to hold the polish. Cotton waste, cheese cloth, as well as light weave t-shirt material can be used. Find your own favorite. (An anal footnote: I recommend Liberon's cotton waste. Its more expensive but softer than typical store cheese cloth).
The outer pad can be made of many materials. References recommend use of linen, muslin, t-shirt cotton, etc. I even have an old reference that recommends the use of silk. If you are going to use a rubber, the key is that the inner pad holds the polish which seeps out into the outer pad. This outer pad is a smooth material which applies the finish to the wood without marring the previous layers of French polish.
Fad: While these terms do overlap, a Fad seems to generally refer to a polishing pad without use of a cover. Materials recommended include cotton waste, cheese cloth, t-shirt cotton, etc.
Proponents of a rubber swear that an inner pad must be used, as the polish should never be directly applied to the outside of the cover. The pad is charged with polish, surrounded by the cover, and the polish seeps onto the cover and thereby onto your workpiece.
However, many people (myself included) apply the polish directly to a fad with no ill effect. This method is particularly easy when a lubricating oil is used to prevent the fad from sticking to your workpiece. I will describe my preferred method later.
As to the size and shape of the rubber/fad/pad there are again so many theories that I'm convinced that there are many ways to do it. Whether using a rubber or fad, one key is that the part which is in contact with the wood must be stretched smooth without wrinkles which can damage the finish.
Regarding size, for large furniture work (such as a big table top) a larger rubber is most efficient. It can fit into the palm of the hand and hold a fair amount of polish.
Since I polish guitars, a large rubber is too cumbersome. I use a small fad or rubber that I hold between the thumb and 4 fingers for better control. Experiment with what works for you.
A couple of notes: The material from which you make your cover whether cotton, linen, muslin, etc. should be washed and machine dried before use. This not only softens the material but eliminates lint and imperfections in the manufacturing process that can scratch your finish. Older rubbers/fads/pads work better than new ones. I keep mine sealed in a jar with a small amount of alcohol in it to keep them moist. At Eugene Clark's workshop he used some tattered bits of cloth that he had literally used for 20 years. He recommended cleaning them periodically in a boiling pot of borax-based detergent (Boraxo, 20 Mule Team Borax). He also uses borax to clean other tools/ materials that have dried shellac on them.
Other Resins:
Today's French Polishers predominantly use a combination of shellac, alcohol, and oils to produce their polish. However, in the past polishers added a variety of natural resins/gums. Invariably these were added either to enhance the finish's durability or to create a higher gloss. Each polisher seemed to have his own formula and the old finishing books are filled with them. Fred Hodgson's classic book, "The Up-To-Date Hardwood Finisher" (up-to-date that is for 1904) even goes so far as to rate the finishing "recipes". Some added ingredients include sandarac, gum copal, gum arabic, mastic gum, gum benzoin, etc. I have experimented with sandarac (supposed to make the finish harder) and hope to experiment with other resins in time.
Light:
As with any high gloss finish, the glossier the finish gets the more likely it is to show imperfections in the workpiece or finish itself. Examining your work with natural light is the best, but if you have a basement shop like I do, this may be impractical. Set up your finishing area with lots of light and preferably one of those swivel arm lamps. As you apply finish, and particularly when you spirit off, look at the finish from a variety of angles to see imperfections.
HOW TO DO ITSurface Preparation:
Every treatise on finishing emphasizes that surface preparation is key to a good finish. French Polishing is no different. Meticulously level the surface of your workpiece. However, you do not have to (nor should you) go to very fine grits of sandpaper. Starting at 80 grit, I rarely sand finer than 220 and on some woods not even that fine. The sanding scratches left by 220, as long as they are regular will be easily filled in your polishing process.In addition, Eugene Clark and others emphasize that having an "open" wood surface, not clogged with sanding dust and not sanded too finely will ultimately create a more beautiful, deep look. In fact, Mr. Clark recommends using old fashioned garnet sandpaper. While it wears out quicker than modern products, he asserts (and my experiments verify) that it leaves a more open surface.
Sealing:
Many finishers already know that shellac makes an excellent sealer. A light wiping of polish is all that is required using quick, circular overlapping strokes. It will dry quickly and the French Polisher can easily proceed in short order.
Filling:
In traditional French Polishing filling was done either with the polish alone (this works but is very labor intensive) or with the addition of pumice. There are several methods of using pumice. Here's the one I use:
Employing a fad (cheesecloth without outer covering) I directly apply (using a squeeze bottle) a small amount of polish (without added walnut oil) to my fad, as well as olive oil and a liberal sprinkling of pumice. As a side note I keep all my liquids (polish without walnut oil, polish with walnut oil, alcohol, olive oil) in squeeze bottles, which greatly increases control of my process.Its just as effective to sprinkle the pumice directly on the work piece, particularly if its a large, flat piece, like a tabletop. As to the rationale for using oil and just a small amount of polish, I am not looking to create a body coat here, since that will, if anything, slow down the filling process. Shellac wants to build quickly and at this point we are trying to slow down finish building in order to facilitate the filling process. Traditionally, French Polishers sometime used additives in their polish at this point in order to slow down the finish build. Sandarac is said to be such a resin. In addition, using oil at this early stage of this process helps bring out the wood's figure. Also, a drop of olive oil is an excellent lubricant, preventing the drying fad from sticking to the workpiece. So use a little more oil than polish at this point. By the way, I keep a small piece of folded paper towel on my bench nearby. After I've squirted the ingredients on the fad, I wipe it on the paper towel. This not only removes excess fluids, but mixes the fluids together in one stroke. Throughout the French Polishing process less is more and the fad should not be much more than damp.
Applying the pad in a traditional circular method is correct for filling, however, make sure you don't go back over areas that have already been filled, as the damp pad will have a tendency to pull up the filler you've just applied.
I find moving my pad cross-grain to be more effective in filling pores. What enters the pores is a combination of pumice, sanding dust, shellac and shellac dust. The pores therefore match the color of the wood.
Shellac will shrink and so pores that seem filled may need more filling several hours later or after an overnight drying. Continue filling in this method until the wood is filled to your satisfaction. But don't worry if later on you notice some pores that aren't perfectly filled; shellac will finish filling them when you body coat.
Bodying:
The process of building a body coat or bodying is similar to that described above. I apply a bit more shellac and less olive oil now (I also sometimes apply an extra drop of alcohol). The shellac I use now has walnut oil in it, as previously described. I don't use pumice on each application, but will use it occasionally to flatten the finish and fill a stray pore. Many polishers lightly sand periodically between coats. If you use this method it should be a very light sanding, just to hit the high spots, with wet-dry paper.
How thick should a body coat be? That depends on your purpose and taste. Traditional polishers generally applied a thin body coat and often considered their job done with just a little bodying after filling.Modern finishers are often competing with nitrocellulose lacquer and other glossy finishes and so go for a greater build and higher gloss. This is certainly true in guitarmaking.
My typical minimum is this: 2 polishing sessions a day for 5 days. What is a polishing session? Shellac dries so quickly that by the time I am finished polishing a piece the place where I started polishing is dry. I will go back and continue polishing, adding polish to my fad as needed. At a certain point you will notice that the workpiece no longer seems to want to accept more shellac. It feels like you are just moving around oil. At that point my polishing session is complete. While I don't keep track of how many coats of polish I've applied in a session, 10 is probably about average. So at 2 polishing sessions/day x 5 days = 100 coats I ultimately apply (it certainly could be even more).
Bodying Tips and Troubleshooting:French Polishing is very much a "by feel" process, so whatever I or anyone else says, you will have to experience, but here are some basics:
The pad/fad/rubber should never stop moving. If it stops for even a second the alcohol on the pad is likely to damage the finish underneath it.
When the polish on the pad is fresh it may appear to leave a vapor trail behind as you rub. This is normal. As the pad begins to dry out, its action will not only apply polish, but the pressure you apply will evaporate the alcohol and seem to burnish the finish's surface. It is this process which makes French polishing different than just wiping or brushing on shellac. Most polishers will therefore start rubbing slowly and rub harder as the pad dries.
Before polishing, I always clip my fingernails. No I'm not Felix Unger! But, there's no worse feeling in French Polishing than hard rubbing with your fad and suddenly clipping the fresh finish with a fingernail. Such a scratch could require major surgery to your finish.
Fixing Problems: As you continue to body you will notice various types of imperfections in your finish. It will take a bit of experience to identify the best and easiest way to fix these problems. By the way, if while polishing you have done something to damage an area, DO NOT attempt to fix it while the polish is still wet. Wait for it to dry well (1/2 hour) before attempting to fix it. Here are my repair techniques, listed from least to most aggressive.
Apply more polish: Most minor swirls and imperfections will disappear with the next coat of polish. The alcohol in the polish will dissolve such minor problems.Use Pumice: A rough surface may indicate its time to apply pumice with your next coat of polish. Pumice will smooth many rough spots with little effort.Alcohol: Slightly more major imperfections can be eliminated by applying a drop of alcohol to your pad. Remember, since alcohol is the solvent for the polish, a pad lightly dampened with alcohol will easily remove the previous layer of polish. Be careful with this technique as too much alcohol will remove more than you want VERY QUICKLY.Sanding: Some people like using sandpaper more than I do. I only use it when the problem clearly has to be removed or when there is a pimple of finish that I can remove with a sanding stick (sometimes I'll use a sharp scraper for this as well). Use wet-dry paper with perhaps a drop of oil for lubrication.Stiffing:
The stiffing process is very similar to "spiriting off", which will be described later. I typically stiff at the end of each day's polishing.
I take my fad and apply a drop or 2 of alcohol to it, as well as a drop of polish. Some polishers just use alcohol, but if you do that the fad will have a tendency to remove finish. With a drop of polish on the pad you'll redistribute, not remove, finish.
Be sure the pad/fad is no more than damp. I check this meticulously by touching the pad to my cheek. The cheek is more sensitive to cold liquid than your hand, so if your pad is too wet your cheek will feel it. Wipe excess liquid off on your paper towel until it feels just damp on your cheek.
I apply my pad to the work piece at first with long slow strokes. I then go back and use my normal circular motion increasing pressure as I proceed. I don't move the pad quickly (I'm not looking for friction and heat in this process), rather I let the increasing pressure I apply give me the results I want. What are those results? First, as previously mentioned, since alcohol is the solvent for French Polish that drop of alcohol will soften the top layer of your finish, redistributing it, smoothing it and increasing gloss. You will be able to see daily how nicely your finish is progressing. Perhaps more important at this point in time, alcohol will remove any excess oil on your finish. This is important, as walnut oil can stiffen and become more difficult to remove if allowed to dry for a day or two.
In addition, some expert finishers (like Eugene Clark) use the stiffing process to expedite their polishing. Eugene will finish a piece in as little as a day, by periodically stiffing the finish. He believes this eliminates the need to allow the finish to dry overnight. Since I rarely have time for more than 2 polishing sessions in a day, I have never attempted this technique.
Flattening the Finish:
Once you have the build of body coat you want, the pores are filled, etc., it is time to flatten your final surface. By the way, I should note that as I am getting close to completing my bodying, I switch from a fad to a rubber (either cotton t-shirt material or linen for the cover) since I feel like I get a smoother final surface this way.
Nonetheless, no matter how meticulous you were, you will need to flatten the finish's surface. You may use powdered abrasives or wet-dry sandpaper (wrapped around cork, a wood block, etc.). At this point, this should be a light sanding, just to flatten your surface and remove imperfections.After a lot of experimentation, I've chosen to use Micro Mesh. If you've never used it - you should. Its great for a variety of functions. A clothed-backed abrasive, Micro Mesh typically comes in packages with grits ranging from 1500 - 12,000 (although in reality the 1500 grit is comparable to 600 grit Silicon Carbide sandpaper). I do a light sanding starting typically at 3600 grit and proceed all the way to 12,000. The Micro Mesh kit comes with a hard foam sanding block which must be used. This should not be a major sanding. If you have more major imperfections to fix, go back to using one of the techniques described above.
Spiriting Off:
Once my finish is flat, I perform what's traditionally called "spiriting off." This process is virtually the same as the Stiffing process previously described (a drop or 2 of alcohol and polish on the pad) although I am much more meticulous in performing it now. When you begin spiriting off, the finish will appear to cloud, but will quickly clear and proceed to become more brilliant than ever. By the end of my spiriting off, I am applying so much pressure on the workpiece that I really get a workout and sweat like a pig!
For many finishers this is the final step, so perform your spiriting off until your workpiece looks like you want it to. Again, I can't emphasize too much being careful about how much alcohol you use. Always err on the side of too little alcohol and polish.Also, as referenced under materials, use lots of light and view your workpiece at a lot of angles to display whatever imperfections may remain. Take your time when spiriting off and examine your work and you will be happy with the results.
Rub Out:
For many polishers once the "spiriting off" process is done, their work is done. Allow the workpiece's finish to harden for at least several days before putting it into service. This is because by applying alcohol in spiriting off you have softened the finish's surface temporarily.
In past centuries, since a super gloss look wasn't desired, many polishers took powdered abrasives or "glasspaper " to knock down the gloss.
I do the opposite and attempt to obtain the highest gloss possible. While you can use a variety of products and methods to rub out a French Polished finish (even machine buffing), I use some very old, natural tools. I wait 4-5 days before rubbing out to let the finish harden.
Tripoli: I find tripoli powder to be a wonderful polishing compound. I use very soft diaper material (turkish towel is also nice) and shake the tripoli onto my workpiece. A drop or 2 of polishing oil (paraffin), mineral oil, or water (for a more aggressive rub) onto the cloth and I begin to rub. The advantage of tripoli, as well as diatomaceous earth (which I also use) is that when rubbed they break down and become finer and finer. Consequently using the same powders I can go from a medium grit to a very fine rub.
After I have rubbed with the tripoli, I wipe the surface off with my cloth. I examine it from various angles and I then proceed to rub again, and wipe off again several times, each time creating a finer compound, as well as less compound on my surface.
Diatomaceous Earth: This natural product, coming from the remains of diatoms, can be purchased in most garden supply shops. Its often marketed as a natural slug bait. The slugs eat it and its abrasive qualities tears up their innards. If you buy it, be sure not to get stuff with any added pesticides. D.E. is very cheap and a small bag will have you rubbing out till you're an old French Polisher. My technique with D.E. Is the same as tripoli. Its very fine to begin with and will become finer as you rub. By the time you have buffed with these 2 compounds, your workpiece should gleam comparably to the highest gloss finishes.
By the way, you may want to use a mask while using D.E., though I find that I use so little its probably unnecessary.
Novus II: If you want to use a modern product, I highly recommend the Novus products. These are marketed to the plastics industry and are by far the easiest, best commercial compounds I've used. And they are safe to you and the environment, as well. Novus II is a mild polishing/rubbing compound and uses Diatomaceous Earth as its abrasive. I use it in the same way I'd use tripoli and D.E. Novus I is a clean and shine product with no abrasive. I don't know what's in it, but it too does an outstanding job of final shining - and in seconds. These products can be obtained at plastic supply stores or on the Internet (there's several web sites that sell the Novus line of products).
Hand Rubbing:
I always assumed that when advertisements talked about a hand-rubbed shine they were referring to rubbing by hand methods instead of machine. So why then, I asked myself did 19th century finishing books talk about hand rubbing. What I found out was that some polishers used their hand as a final rub out tool. If you think about it, it makes perfect sense. The skin of the hand is abrasive yet soft with creases which hold rubbing compound, much like a leather strop holds compound when used for sharpening tools.
After I have rubbed out using tripoli and/or diatomaceous earth and have wiped off the piece, I begin to rub the piece using the palm of my hand. By the way, those with heavily calloused or rough hands should not try this technique.
You will find that the piece you believed had no more compound on it, still has plenty, which your hand will rub into the finish, giving it a final buff even superior to your cloth. This too will give you your aerobic workout for the day.
Another Technique for the Adventurous: German piano finishers and others used this technique for final polishing. Take sulfuric acid and add it to water (1 part acid to 10 parts water). Make sure you add acid to water and not the other way around. Sprinkle Vienna Chalk (a nasty feeling and smelling fine grit compound) on the work piece. Pour some of the acid solution into the palm of the hand and rub the solution and chalk onto your workpiece creating a paste, which when dried can be wiped off. I've never tried this technique. If you do, let me know how it goes - if you can still type!
Waxing:
You work is now complete and you wish to wax you piece. Use your favorite method. Favoring a very light waxing in guitar making, I use my diaper material with a drop or 2 of mineral oil and wipe it across a block of carnauba then rub my workpiece. The resulting minor waxing fills any minute final imperfections in the shellac.
Holding and Supporting Work:
Here's a few hints and drawings regarding holding work to be French Polished, obtained from the book, Staining and Polishing (see references at the end).
Your bench should be much higher than a standard woodworkers bench, to save your back and arms. Three feet high for an average height is suggested. Small pieces can be suspended on temporary battens which project from the bench top, as show in the illustration.
For polishing turned objects such as legs, loose bracket boards are used.
What Can Go Wrong?
One of the things that the finisher needs to learn is that high gloss finishes show more imperfections the glossier they get. The workpiece that looks perfectly sanded may show problems with a coat or 2 of finish. And the completed French Polished finish may show imperfections as you spirit it off to a high gloss. Experience will tell you whether you need to add more polish, use an abrasive to remove a problem, or spirit off more. One nice thing about shellac is that you rarely should have to remove it to eliminate a problem.
One thing that has been emphasized to me is that products with silicone should be eliminated from the work area where you polish. Apparently even a few parts per million of silicone can damage the shellac finish as you polish, causing an effect that looks like crazing in other finishes.
Sweating is the most common of French Polishing defects. This is often caused through too much use of oil or failing to clear excess oil during the Polishing process. The oil breaks through the lac surface showing innumerable little fine lines. Another cause can be bad shellac. The problem can be mitigated with an occassional wipe with a soft damp cloth. If the problem continues it will be necessary to remove all signs of sweating by washing the surface with lukewarm water and a mild soap or pumice and repolishing the surface.
Cracks are sometimes caused by improperly seasoned wood, which swells and shrinks so extensively that the finish can crack. The piece should be cleaned, and repolished, at first using more alcohol than normal to make sure that the existing polish is softened, so that the new polish can adhere to it properly.
Finger Mark: After a few days of drying, a French Polished surface should not show finger marks. This could indicate the use of too much oil, or the polish itself is too soft. The piece should be cleaned and spirited off and re-bodied up.
Well, there's lots more to tell, but that's it for the basics. Have fun becoming addicted to French Polishing.
Feel free to email me with any questions or problems: davewe@pacifier.com
REFERENCES:The following are my favorite older reference books:
- The Up To Date Hardwood Finisher, Fred Hodgson, Frederick J. Drake &;Co., 1904. Classic late 19th century work was published in enough versions over the years that finding a copy is not too hard. A fine reference with a good chapter on French Polishing.
- Staining and Polishing, no author, Evans Bros. An excellent English reference, predominantly on French Polishing. I don't know how obtainable this is.
- Coloring Finishing and Painting Wood, A.C. Newell, 1930, Chas. A Bennett Co. A good general finishing reference by a popular writer. Nice chapter on French Polishing, and the rest of the book is valuable as well.
- Wood Finishing, Harry Jeffrey, 1924, The Manual Arts Press. Good chapter on French Polishing.
- French Polishing and Enamelling, R. Bitmead, 1923, Crosby Lockwood and Son. A nice 100 page book, predominantly on French Polishing. Another British work, I don't know how obtainable it is.
- The French Polishers Manual, no author, E. F. N. Spon Ltd. This little book has been published in many different versions, the last by Woodcraft Supply Corp. I have that version, as well as an older version and they are quite different in text. Some valuable information, but not my favorite book.
- Wood Finishing, W.A.G. Bradman, W. &;G. Foyle Ltd., 1950. A nice 100 page book, about haf on French Polishing. Pretty traditional approach for a relatively modern book.
- Spons' Mechanics Own Book, E. F. N. Spon Ltd. , 1889. 700 pages on every aspect of 19th century woodworking. One of my favorite books, it has a strong chapter on French Polishing, with lots of arcane recipes. Despite its age, I have seen it several times, so a copy may be locatable.
- The Practical Woodworker, Bernard Jones. This classic reference has appeared in many versions. The original 4 volume work has a good chapter on French Polishing.
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