Spraying Shellac

It was impossible to find any info on this on the net, and since I have been working on it very hard for several months, and have it figured out, thought I'd post my experience. I have been spraying lacquer on the hammered dulcimers that we build now for over 20 years. Figure I have finished at least 5,000 of them myself, so am pretty good with a spray gun. But lacquer is toxic, and even though I protect myself very well with a respirator, and complete HAZMAT suit, I still get a small dose. So I had been looking around for several years for a healthier alternative. Water based lacquer isn't feasible in my shop because it is temperature sensitive, and I can't maintain the warm environment year round. It is also a product of chemical companies, and works much the same as solvent based lacquers. But I finally found the right alternative... Shellac!

 Shellac is old fashioned. It is what was used before lacquers came along over 100 years ago. It has some advantages over lacquer, but it is different, so needs to be handled differently. But once you learn how it works, I think you'll like it as much as I do. One advantage is that it is totally nontoxic. Shellac is a natural material, produced by a bug that lives in India and Thailand. It is harvested by hand, and much of the processing is done by hand. It is edible, and you have eaten lots of it like in coatings on candy and medicine.

Shellac comes as flakes that you dissolve in denatured alcohol. I get my flakes from www.shellacshack.com. They come by the pound in several different colors and grades. Denatured alcohol is available at home centers, hardware stores, and paint stores by the gallon. Not all brands are the same, I use the Sunnyside brand, and it works well. There is lots of stuff on the net about applying shellac by brush or pad, but none about spraying except to say that it is possible. So I had to do the experimenting myself. This is how it is done.

Use what is called a one pound cut. Which means dissolving one pound of shellac flakes in one gallon of alcohol. It takes a while for the flakes to totally dissolve. Just put them in the alcohol, and stir several times a day, and they will eventually completely dissolve. Use a glass jar for dissolving the flakes.  It may take several days, be patient. Once they are dissolved, I filter the solution through a paint strainer into a clean plastic milk jug. Don't try to store shellac solution in metal containers, it is corrosive.

Shellac at a one pound cut can be sprayed through any gun that will spray lacquer. I am still using lacquer for some things, so I have a separate gun reserved for the shellac since the solvents are totally incompatible. Keep your gun clean! You want to make sure all the shellac solution is out of there before the end of the day. You can leave some alcohol in it, but no shellac.

Shellac can be sprayed directly on bare wood, but the alcohol being a polar solvent will raise the grain of some woods. Most of mine is sprayed on birch ply, so I need to seal the wood before spraying. I have found Minwax Wipe on Poly to be ideal for this. It can be used straight, or cut 50% with mineral spirits, either way. Wipe it on like it was stain, wipe the excess off, and let dry over night, and it is ready to go first thing in the morning. Shellac will stick to anything, so there are no compatibility issues.

One big issue here... GET RID OF THOSE OILY RAGS IMMEDIATELY. In the winter mine go straight in the wood stove. In the summer, they get spread out on the driveway to dry. DO NOT LEAVE THEM IN YOUR SHOP, they can spontaneously combust. I know a contractor in Missouri that burned their paint building down 3 times before they figured this out.

Spray the shellac thin, just like you would lacquer, but you have to be very careful if spraying it vertically. It runs and drools much easier than lacquer. So I lay my dulcimers flat on a turntable, and spray that way. It only takes a few seconds for the alcohol to gas off enough for me to turn the dulcimer over, or hang it up out of the way. I have a bed of nails on the turntable so the dulcimer is lying on the tips of the nails, not a flat surface. Standard paint room trick.

Best thing to do is 2 light coats, then let dry for an hour or so, then scuff down with 320# or 400# paper. Then another 2 light coats. The stuff will load your sandpaper so be prepared to use more than you would with lacquer. Shellac is by nature a high gloss finish. You can control the amount of gloss you get by how much you spray on. I want a satin gloss, or maybe just a little higher, so I stop at 4 coats. If you want more, scuff down again, and put on some more.

If the wood is sealed well, the shellac will build up a nice flat coat, and next day I can polish it. If it is rough, I will sand it flat with 400# paper, then rub out with 0000 steel wool, and carnuba wax. I use the Trewax brand from the hardware store. After buffing the wax, the finish has a soft matte glow, and feel that is out of this world. If the finish is fairly smooth, I will skip the steel wool, and only lightly go over the surface with a worn out piece of 400# paper to take off any dust motes that might be there. Then wax with a rag, no steel wool. This gives me the gloss that I really want, which is just enough so there is a little shine, but not glassy.

For the top of the dulcimer, since the bridges are not fastened down, I use Meguiar's #7 Glaze which is at the auto parts store. Wax is too slick, and the bridges might moved too easily. The Meguiar's seems to do the job just fine, and isn't so slick.

Color: Shellac comes in several colors depending on how refined it is. Platina is almost water white. Super blond has just a little color, you'd have to put on a lot to see it. Blond has some color, and is nice. Garnet is the old fashioned orange that you have seen on wood work in old homes everywhere. I use the dewaxed flakes. I like to mix Blond and Garnet shellacs. I mix up separate jugs of the two colors, and find a mix of 75% Blond, and 25% Garnet gives my birch ply a beautiful golden glow. I like this stuff a whole lot better than lacquer.

Top coat: If for some reason you want something else on the surface, you can use the shellac just for color coats, then top coat with anything. Shellac is the universal sealer, and anything will stick to it. I sometimes do this if I want the color, but also need the dependable semigloss of lacquer without the wax. Works fine.

So the disadvantages of shellac are that it is a little more complicated to do right, takes a little longer. I don't think it costs more, about the same as the Sherwin Williams lacquer I have been using. You also have to think ahead to have it ready when you need it. It also won't keep forever, needs to be used within 6 months of being mixed up.

But the advantages out weigh the disadvantages. I no longer need the HAZMAT suit. I do use the respirator, but as soon as the surface is dry, I can shut off the explosion proof fan in the spray room, and there is no smell at all!  No gassing off for days, and making me sick. I can spray the shellac in the morning if I want to, polish it up after lunch, and we can put the strings on the same day. No waiting for several days for the dulcimer to quit stinking. Also no worries of sending it to somebody with a chemical sensitivity, and making them sick even after we can no longer smell it. And we are not supporting large chemical companies, instead we are supporting small business both in India, and here, like Shellac Shack. And it is much better for the environment.

Finishes

I have been spraying lacquer for twenty years now. Hated it the whole time. It is nasty stuff. I have to wear a complete hazmat suit, respirator, rubber gloves, boots, and still I can't help getting a small dose. It is also bad for the environment. I can't see how I am being a good steward of the Earth by spraying these chemicals out into the air. But it is fast, and looks good.

I have been looking for an alternative for years. I looked at water borne lacquers, but they require a warm environment, and warm materials, which I can't guarantee year round. Whatever I do has to be sprayed. Brushing or wiping finishes on are too slow, requiring multiple coats and risk dust settling on them before they cure.

So last year I discovered that I could spray shellac, then when it is dry lightly sand it, then rub out with steel wool and wax. This is a very nice finish with a soft satin glow, and feel that is out of this world. We like it a lot. It is an all natural finish, completely non toxic, and totally green. Shellac is an insect resin that is collected in India and comes as flakes of various shades which are then dissolved in denatured alcohol. It can be sprayed on all in one session, unlike the lacquer which requires two. And also unlike the lacquer, it doesn't gas off (stink) for several days. The shellac is well cured within a couple hours, and can be rubbed out the same day. So we are switching all the Phoebe and Wood Thrush dulcimers to the new shellac and wax finish as of this year.

Still experimenting with another natural finish for the Warbler and Whippoorwill dulcimers. I have discovered that a few drops of Japan driers added to Tung oil makes it cure super fast, almost as I am rubbing it on. So at least two coats can be applied in a day, and a third the next day develops a very nice semigloss shine. This one will have to wait for more experimenting, but looks promising.

Two years ago I developed a completely different approach. Since I was a cabinet maker, I am know how to work with high pressure laminates (Formica). So I designed a dulcimer made of Okoume marine plywood that I could then cover with whatever laminate the customer chooses. They work just great, sound wonderful, are water proof, and stay in tune. And the design possibilities are unlimited. We have built a fair number. They never fail to get noticed. One of our friends had us make one for her the color of blue jeans. Another one looked like a beautiful piece of dark marble with mica flecks in it. There are wood grain laminates, some with textures, metals, and every color imaginable. Call us if this sounds interesting.

Wood selections

For many years we built the Whippoorwill and Warbler dulcimers with solid Honduras Mahogany tops. We were buying it from some folks in St. Louis that imported it directly. Otherwise known as "Genuine" Mahogany, it was a truly great tone wood. But in the very late 1990s an international ban was put in place on trade of Honduras Mahogany taken from its native range. By 2007 the supply of it had dwindled to the point that it became unavailable for most purposes. Even the big guitar companies that have depended on it historically can't get it, and all of us as instrument builders have scrambled to find substitutes.

There are several African woods that are now in use and called mahogany. They may look similar, but none are as good. They are harder to work, not as stable, and won't sound quite the same. The most prevalent is Sapele. It is the right color, and all of it that is imported is quartersawn because it has to be to remain stable. It has a striped look to it because the grain is constantly changing directions, and it gives it a shimmer under a finish that can be very pretty. Another wood is Khaya, which is slightly darker and more dense. Just beautiful under a finish, but too dense for hammered dulcimers.

We decided since Genuine Mahogany was no longer available that we should quit using tropical hardwoods altogether. A lot of wonderful wood grows right here in the USA, and it is all sustainable. In fact, American forests have increased in volume of board feet every year since 1911! So for us it was a matter of figuring out which woods to use. After trying several different woods, we settled on Cherry for our Whippoorwill and Warbler models, and a surprise; Poplar for the at the time new model Wood Thrush. We tried Quartersawn Walnut which is a great tone wood, but couldn't find a source for it. The best Walnut in the world grows right here in Iowa, but nobody cuts it quartersawn which would be necessary for stability of a piece as large as a dulcimer top. We would occasionally find a few quartersawn boards in a randomsawn pile, but couldn't get our supplier to sort out the stuff for us we'd need.

No matter, Cherry turned out to be just great. Here's where experience as a woodworker comes in. The Forest Products Lab publishes tables of data on various woods and their properties. They have shrinkage tables on all the major woods, but their figures are for percent shrinkage from green to oven dry. This is good for a general idea, but the figures we really want are percent shrinkage from 12% to 6% moisture which is the range a kiln dried board will go through in a normal year. There aren't any figures like that out there anywhere. You just have to know what works, and what doesn't. According to the FPL figures, Douglas Fir ought to be good, and we made some dulcimers from it. But it moved a scary amount within our range, a 20" wide board would shrink 1/2"! According to the FPL numbers Cherry should not work for us, but it does! It is wonderful, and within our 6% to 12% range of moisture seems totally stable. A very worthy substitute for Genuine Mahogany indeed! And it sounds great. And best of all it grows right here in Iowa. There is a producing mill 3 miles from our house, and they do a wonderful job with their saw mill and kiln. Absolute quality. I buy most of the lumber we use from them, and feel good that it is locally grown, locally milled, and used locally.

I believe that the market was used to Mahogany dulcimers, and still wanted them. Don't blame them, the old stuff was great. But Sapele and others are not the same, and we as consumers should not demand it. We are contributing to the cutting down of the tropical rain forests. If we ask for products made from American woods, we are contributing to our own economy and the use of sustainably produced local woods. This in turn enhances the value of our forests. They are a treasure.