Bob Miller explains why you should head to the local liquor store before applying your next shellac finish
By Bob MillerAug 28, 2019
Shellac is a wonderful finish with a fantastic range of applications and possibilities. It can range from an easy utility finish all the way up to the finest of fine polished finishes. Here is a way to make your shellac finishes better and easier to use. This gets a little scientific, but stick with me, it’s worth it in the end.
It is very important to think about the solvent used to dissolve the shellac. Most people simply use commercially available “denatured” alcohol. Denatured alcohol is a general alcohol-based solvent used for a variety of applications across many industries. Mixed with shellac, it will produce a serviceable finish. However, it has some problems when it comes to shellac.
The first is that there is no industry regulation regarding what precisely constitutes denatured alcohol. This means that some brands are cut with water to increase their volume, often by as much as 20%.
The second is that there is no way of knowing what kind of alcohol was used to produce the product. Some brands contain methanol, a cheaper, more volatile and dangerous form of industrial alcohol that can be used to bulk up the volume of solvent. This inconsistency makes it difficult to predict the behavior of the shellac both as it dissolves and as it dries as a finish.
Quite apart from the mysterious composition of commercially available denatured alcohol, there is another major concern. To prevent people from recreationally drinking this industrial solvent, denatured alcohol contains substances such as denatonium, benzene, and pyridine. These compounds are called denaturants, hence the term “denatured” alcohol. These additives are meant solely to help prevent people from drinking industrial alcohol by giving it a bad taste and a powerful smell. They do nothing for your shellac! In fact quite the opposite, as these additives interfere with the dissolution process and remain in your finish after the alcohols have evaporated out. This can lead to difficulties in drying, polishing, and applying a fine shellac finish, as well as interfering with the clearness of the final finish.
Can the Can(ned) Shellac Creative director Mike Pekovich demonstrates how easy it is to make a batch of shellac from flakes.
In short, denatured alcohol is an unpredictable, dangerous, unhealthy, poor-quality solvent for shellac that will make your finish harder to use as well as shorten your life. Don’t worry, though; I have a solution.
Prior to Prohibition here in the United States, woodworkers would have simply mixed their shellac with a high proof, grain-derived alcohol that contained a minimum of water. It was only after Prohibition that all of these denaturants were added to make industrial alcohol undrinkable.
So if you’re looking for a pure, consistent supply of high-strength alcohol that doesn’t contain this spectrum of chemicals., think about the bottom shelf at your local liquor store. Everclear and Diesel are two brands of nearly pure alcohol that contain less than 5% water. They are commercially available in most states and are the perfect solvent for shellac, with no denaturant and a minimum of water.
Once you switch to pure alcohol for your shellac you will wonder how you ever got along with denatured alcohol. Pure grain alcohol will dissolve your shellac more smoothly and will build your finish more quickly. So take a trip to your local liquor store and pick up some solvent, give it a try with shellac, and see what you think when you’ve used a traditional solvent for your traditional shellac finish.
-Bob Miller is a custom furniture maker and woodworker based in the Charlestown neighborhood of Boston. In addition to his own line of work, Bob managesThe Charlestown Furniture Makers, which is an 18-tenant co-op, solar-powered woodshop located in the Sullivan square area of Charlestown.
Once you switch to pure alcohol for your shellac you will wonder how you ever got along with denatured alcohol. Pure grain alcohol will dissolve your shellac more smoothly and will build your finish more quickly.
Denatured alcohol is ethanol that's been mixed with toxic additives. Ethanol — also known as grain alcohol — is alcohol at its most basic. However, denatured alcohol is not fit for human consumption because of these additives and is instead used as a lower-cost solvent or fuel.
I've used Kleen Strip Green denatured alcohol successfully. It dissolved shellac from the brush in a few minutes and nicely thinned the shellac from bullseye brand. It appears easy to find, from smaller hardware stores to the big boxes in the US.
Formulations, of denatured alcohol, which should be used as a solvent or fuel, intentionally contain 'contaminants' such as pyridine and/or methanol to prevent its recreational use. At the same time, these additives make denatured alcohol toxic and potentially fatal if consumed in large quantities.
Denatured alcohol and isopropyl alcohol have similar uses, but they differ chemically. Denatured alcohol is ethyl alcohol with toxic or bad tasting additives that make it unsuitable for consumption. The chemical formula of ethyl is C2H6O and the formula for isopropyl alcohol is C3H8O.
Isopropyl alcohol shouldn't be used instead of denatured alcohol due to its lower concentration and water content (water may cause problems due to its slow evaporation rate). Its toxicity also means isopropyl alcohol can't be used in food preparation or food processing.
It is very important to think about the solvent used to dissolve the shellac. Most people simply use commercially available “denatured” alcohol. Denatured alcohol is a general alcohol-based solvent used for a variety of applications across many industries. Mixed with shellac, it will produce a serviceable finish.
Denatured alcohol assists in cleaning the wood after sanding it to prepare it for other projects. Wear protective gloves and treat the wood outside in a dry area. Use a lint-free cloth and wipe the wood with undiluted denatured alcohol. The denatured alcohol will dry quickly and clean the wood.
I used a piece of steel wool, grade 0000. I poured a little of the denatured alcohol onto the steel wool and started scrubbing. It worked so well! It was taking off the top layer of finish!
Nearly all denatured alcohol is used as a solvent/stripper. In these uses it simply evaporates into the air, contributing to ground-level ozone. While its use for camp stoves likely contributes little to VOC emissions overall, it isn't feasible to try to sell a campstove-only formulation.
Isopropyl alcohol (rubbing alcohol) and denatured alcohol are not the same. They share some similarities, but have different chemical structures and have different uses. They are similar in that they can NOT be consumed by humans. They are both toxic if ingested.
In its pure form, grain alcohol contains a minimum of 95 percent ABV. Grain alcohol that is 200-proof (100 percent ABV) is not for human consumption. It can be made from corn, rye, wheat, grapes, grains, sugarcane, tubers, and beets. Grain alcohol is harsh in its undiluted form, so you don't consume it straight.
Denatured alcohol, also known as methylated spirits, metho, or meths in Australia, Ireland, New Zealand, South Africa, and the United Kingdom; and denatured rectified spirit is ethanol that has additives to make it poisonous, bad-tasting, foul-smelling, or nauseating to discourage its recreational consumption.
Everclear is also used as a household "food-grade" cleaner, disinfectant, or stove fuel alcohol because its fumes and odor are less offensive than isopropyl, rubbing, and denatured alcohol which are toxic to breathe or drink.
Is Everclear Denatured Alcohol? Everclear is a non-denatured mixture of ethyl alcohol derived from corn. Everclear 190 proof (95% ABV) is legal in some states for use in beverages, but it may also be available in 151 proof (75.5% ABV).
Introduction: My name is Clemencia Bogisich Ret, I am a super, outstanding, graceful, friendly, vast, comfortable, agreeable person who loves writing and wants to share my knowledge and understanding with you.
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