Shellac

Shellac has been used as a finish for hundreds of years.  Woodworkers like it for the beautiful tone it gives to wood. It also helps that it is easy to apply and easy to repair.

Shellac dries hard and won’t yellow or darken with age. This makes it a great sealer beneath other finishes. I like to use it to keep pine pitch from bleeding through paint. It can also be used to help prevent blotching. It hardens on top of the surface of the wood, making it is a good barrier for blocking impurities from seeping through a finish. It is extremely fast drying so you can build coats quickly.


Shellac comes from the resin of the lac bug. The processed resin, called lac, is dissolved in alcohol to make the finish that woodworkers use.

By itself, lac is non-toxic and non-polluting. In fact, lac is used in many products, including in the food industry. It is the denatured alcohol added to dissolve the lac that is toxic, so the usual precautions apply when finishing with it. However, once dried, the solvents evaporate and the hardened finish is again non-toxic.

shellac

Lac is naturally waxy. Different grades of shellac remove various amounts of that wax. If you are using it under another finish it can be important to use a de-waxed version.

Some finishes will adhere to any shellac, but with others the wax prevents bonding. I don’t know enough about finishing to know which ones are safe to use, so I just make sure to use de-waxed if I’m using it in conjunction with another finish.


You can buy shellac ready mixed or you can make your own.  The label on commercial brands should tell you whether it is de-waxed or not. To make your own you buy flakes and mix them with denatured alcohol. The flakes will be marked de-waxed or not.

mix your own shellac


Shellac has a definite shelf life. If you are buying it pre-mixed look at the date on the container. Different brands add agents to extend the shelf life. I mix my own, so I’m not familiar with the different brands.  When I mix my own I make enough for whatever project is on hand, or sometimes if I know I’ll be using it later I’ll make enough for a couple months.

If you aren’t sure how old your mix is brush it on a board and wait a few hours. If it’s still tacky chances are it won’t ever dry. Toss it and try again.

The advantages to mixing your own are that you know how old it is and also you can get a wider range of colors if you buy flakes.  The colors range from “super blond” (clear), to garnet and amber. Colored shellac can give a real depth and warmth to wood. I especially like garnet on walnut, it brings out the richness of the wood.

shellac


Another advantage of mixing your own is you can decide how diluted to make it. The mix is identified by the ratio of alcohol to shellac, called “cuts.” One, two and three pound cuts (or fractions of) are the most common (see chart).








Pound Cut
Denatured AlcoholShellac Flakes
1
1 gallon
1 pound
2
1 gallon
2 pounds
3
1 gallon
3 pounds


or for smaller quantities:
Pound Cut
Denatured AlcoholShellac Flakes
1
1 pint
2 oz
2
1 pint
4 oz
3
1 pint
6 oz



Custom Search

I’m not particularly precise when I mix my own (truth be told I tend to wing it), but in general I use a 1 pound cut as a wash coat, 2 or greater pound coat for follow up and building the finish.

To mix, first crush the flakes to help them dissolve. Put them in a clean plastic or glass container and add the appropriate amount of alcohol. Mix thoroughly and set aside. I usually leave the container on my bench and give it a shake when I think of it. I let it sit overnight and by morning it’s good to go.

The darker flakes tend to have more wax. However, it’s easy to filter it out. If you are mixing your own you can wait until it settles then strain it through a coffee filter. The final mix should be clear rather than cloudy.


Shellac can be brushed, sprayed or wiped on. The trick is to use a high quality brush or a lint free rag (I’ve never sprayed it, so you’re on your own there) and apply in long, slightly overlapping, strokes.


If you find that your rag or brush is dragging by the end of the pass it means your mix is too thick. Dilute it slightly with alcohol and try again. If you hate the look you can wipe it off with a rag dipped in alcohol. The same applies to repairs. If you get a scratch you can wipe it out with alcohol, or just put on another coat.


Give it a try.

Happy finishing....






For those who are interested in this site check out the links and feel free to sign up for my newsletter Wood Shop News.

Contact me if you have questions or would like to discuss a custom order.

Please note: woodworking is potentially dangerous please read my disclaimer before using any information on this site or any site you may be directed to from here. Thanks for visiting.
top of "shellac" page