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This FAQ is by no means complete.
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- What solvent do I use, and how do I dissolve it?
Use 190 proof (less than 5% denaturants) denatured alcohol .
We now supply a High Quality 'Select' Denatured Alcohol. We ship it in quart containers so you don't have to pay a hazard shipping fee. You can also find 'high test' anhydrous denatured alcohol at a chemical supply house. A lot people (me too) get along fine with a high quality hardware store denatured alcohol [look for less than 5 % denaturants] (in Canada it's known as methylated spirits). Though the shellac flakes & buttons are a thing of beauty to behold, they really do melt more quickly if they're crunched to tiny bits before going into the solvent. I find wrapping the buttons in heavy linen, and then beating them with a wooden mallet to be a good procedure.
Use a glass or plastic container, add measured amount of alcohol and sprinkle in your dry shellac. Shake every 10 minutes or so for an hour, then let sit overnight. A simple to way to mix an approximate 3# solution is to mix 3 parts solvent to 1 part flakes by volume.
Another way to speed up dissolving is to place your container of flakes and solvent in a pan of hot water.
DO NOT HEAT ALCOHOL OVER AN OPEN FLAME!
I'm so cautious, I won't even use an electric hot-plate.
I heat a pan of water in a different location, then let the shellac container steep, away from any other heat or flame, you don't need boiling water, just hot.
- How do I apply this stuff?
Before you even think of applying shellac to your project, you've got to strain it! This goes for even the finest grades of blonde shellac. Little bug parts and other impurities always seem to make it into the shellac flakes. Use a multi-folded piece of cheese cloth, paint strainer, or clean old t-shirt material.
Shellac may be sprayed, brushed, padded, polished, or even wiped on with a rag. Woodturners use a tiny pad and finish their projects right on the lathe! Since shellac dries so quickly, it's not very self-leveling. To slow drying, improve leveling add some of our Shellac Retarder.
- Brushing - use the best brush you can afford. Check out a recent article on how to select the proper brush. The old-timers scoff at anything less than a badger hair brush. You must work quickly.
Dip the brush no more than 1/3 of the way into the shellac and tap it. Don't wipe the brush on the side of the jar. You'll pick up dried shellac sludge and end up brushing it on your project. Begin your stroke an inch or two from the end, and lay down the shellac with a light touch, moving toward the far end. Then quickly brush back over to the beginning. It's easier to demonstrate than explain. Then brush to the far end. Be careful around the edges, because the shellac will want to collect there, creating a fat edge. Brushing is much less hassle if you pre-finish your project before assembling it.
- Wiping - it's just like brushing, only use a thinner cut, like 1# or 1.5#. Wrap a lint-free cloth around something absorbant like a wad of cheesecloth or lamb's wool. Squirt enough shellac on the inner pad to make it as wet as a sponge you might use to wipe your kid's face with, but not dripping. When the pad begins to stick, add more shellac.
- Padding - this is like wiping, only you work a bit slower, apply a little more pressure and you move the pad in gentle circles as though you were waxing Dad's old Buick. That is, it's not much like wiping at all except you're using a pad. A clever trick to use when the pad starts sticking (and marring the finish) is to lubricate it with a couple drops of mineral oil (get it at your pharmacy). The mineral oil won't affect the shellac as it goes on. Clean the mineral oil off later, with a naphtha dampened rag.
- French Polishing - is best explained by the true experts. I know of a couple, and here are their stories. Dave Weisbord, a budding luthier, tells us about his adventures in French Polish. Pete Taran, one of the founders of Independence Tool (now owned by Lie-Nielsen Toolworks), tells us how it's done.
- Spraying - for HVLP sprayers, I've had customers go as thick as a 1.5# cut and produce wonderful results. Follow the directions for your particular spray-gun set-up. Clean up is easy with hot water and a mild ammonia-based detergent. Shellac Retarder (not lacquer retarder) will help eliminate ovespray and any orangepeel
- How long should I let it dry?
Depending on humidity, allow at least 20 minutes to an hour between coats. Shellac is dry to the touch in minutes, but there will still be solvent trapped under the surface. With good drying conditions, allow a few days drying time (a week to ten days is better) to allow the shellac to thoroughly harden before rubbing-out. If Shellac Retarder is used, longer drying times between coats and to final cure are required.
- Is it dangerous?
Ethanol is the primary ingredient in denatured alcohol, methanol or other alcohols are used to 'denature' the ethanol, discouraging us from drinking it. Never mix or use shellac in the presence of an open flame. Also, methanol and other nasty denaturing agents are easily absorbed into the skin, nasal membrane and even your eyes. Prolonged exposure to high concentrations of alcohol fumes can leave you enebriated. Continued exposure to high concentrations of methanol can damage your optic nerve.
Avoid these problems by always working in a well-ventilated area, using 190 Proof solvent that has 5% denaturing agents, and by wearing gloves (vinyl works great) and a respirator specified to filter Volatile Organic Compounds (VOC).
In short, do not eat or drink your shellac nor any of its solvents.
- What do they mean by "3# cut"? Pound Cut Mixing Chart
The cut refers to how many pounds of shellac flake are dissolved in a gallon of alcohol. Several thinner coats are easier to manage than trying to apply thicker coats. To make a '1 Pound Cut', mix 4 Oz. of dry shellac flake into 1 quart of denatured alcohol (1/4 lb. in 1/4 gallon). It doesn't have to be exact, this isn't rocket science.
- How should I store the dry shellac flakes? Kept in a cool, dry, dark place, the shelf life in my shop is 3+ years. Your mileage may vary. Never leave your shellac in a closed car. It will melt into a brick. Of course the good news is you can always smash the brick and then melt it down.
- How long will it last in solution?
The rule of thumb is 6 months. Once dissolved, shellac begins a process called esterfication, where its ability to dry to a hard shell begins to degrade. Always date new jars of shellac you mix up, especially if you're not going to use it right away. If it's a few months old, test it on a scrap piece. It should dry to touch in 15 minutes at the most. If not, it's no good. You can still use it to make a tack cloth. On the other hand, don't throw out potentially good shellac, just because it's been sitting around awhile. I've successfully used shellac that's more than 18 months old.
Remember, if you don't test on scrap,
you'll be testing on your project!
- My finish looks cloudy. What did I do?
This is trapped moisture known as blushing and is a common occurence when too many coats are applied too quickly, under high humidity, or the moisture content is high in the solvent. Let the finish dry for a day, then lightly and quickly wipe it down with a 1/4# cut of shellac, or straight alcohol. This will allow the trapped moisture to evaporate.
- How should I prep my workpiece?
I won't get into too many details of smoothing the surface of your project. Suffice to say it should be smooth as a baby's behind. Sand, scrape or plane to your heart's delight. If you're sanding, don't be tempted to go to fine grits too soon. Much of sanding displeasure stems from too much sanding at high grits, getting you nowhere. Don't go to the next grit until the scratches on the surface are uniform. Of course, if possible, avoid sanding by discovering the joy of hand planing.
The easiest thing to do to make sure your wood isn't contaminated with wax from your planes is to wipe down with mineral spirits (paint thinner). Shellac will not adhere well to a waxy surface.
- I'm wiping shellac, and the surface is rough; it's not taking any shine, even after four coats! What's wrong?
Nothing. The alcohol will raise the grain, especially in softwoods. This is expected - good even. Knock down the raised grain and little nibs with some 320 grit silicon carbide (available at some art supply and automotive finishing stores, if your local hardware store doesn't stock it) sandpaper on a rubber sanding block. Lube with Wool Lube to reduce build-up on your sand paper. Wipe off the lubricant with a paint-thinner dampened rag, and then apply thin coats of shellac as required.
- What kind of coverage should I expect?
(How much should I buy?)
That is the million-dollar question. The only thing worse than blowing a bunch of money on finishing supplies you don't need is being caught short while in the middle of a project. Fear not, there is hope. Remember, in flake form, and stored properly, shellac has a shelf life of around 3 years. Keep the flake cool, dark and tightly sealed. Therefore you can stock-up and mix only what is needed for the job at hand. The thing about shellac is that it will take a tremendous polish at extremely thin layers. A little goes a long way.
For general woodworking, like cabinetry, bookcases, tables,
chairs, and so on, 1 lb. of shellac in 1/2 gallon denatured alcohol
(a two pound cut) will easily cover 160 - 200 sq. ft.
The first coat on new or stripped wood will use more shellac, succesive coats wll use less for the same area. Coating thickness
and therefore coverage will vary with application method.
Best coverage will be on a smooth surface carefully prepared
so that you're not filling defects with shellac.
- What shellac goes with which kind of wood?
That is the two million dollar question. This is a higly subjective area. Generally-speaking, lighter shellac looks good on lighter woods, unless you're looking to bring out figure in woods like curly maple, in which case you're probably going to use a dye stain under the shellac. Of course you can always use garnet to darken-up bland woods like alder, pine, yellow birch, etc. That's why we have pictures in the customer gallery, so you can get an idea what other folks are doing, and what to expect. That's why we offer sample packages so you can experiment. Two of my favorite grades to use on red oak are (any one of) the buttonlacs, and/or dewaxed orange. It really brings out the red in the oak.
- Can I use shellac for everything?
Of course! -- Just kidding!
Shellac is prone to damage from lower alcohols, heat, and alkalais (strong detergents, ammonia). This makes it a poor choice for kitchen base cabinets, counter tops, and uncovered dining tables.
Contrary to popular belief, dewaxed shellac is quite water resistant (this is why shellac-coated pills don't melt in your mouth, but they do in your stomach).
If you love the look of shellac (and who doesn't?), you can avoid the plasticky look of thick urethanes & varnishes, by finishing a table with shellac, then top-coating with a good spar varnish or Behlen Rockhard Table Top Varnish.
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