We painted two pieces of furniture today. One piece had a peculiar odor in the drawers. I fixed it with a coat of Shellac, using Zinsser liquid Shellac, a staining pad, and applied it directly to the inside of the drawers. Here are some tips to follow when using Shellac.
The easiest and most effective way to apply Shellac is to wipe on one or two coats with a cloth pad. The friction you create with this wiping action really seems to get the Shellac down deep into the substrate rather than just laying on top of the surface. Plus it's super quick. Wearing a pair of disposable gloves, simply dip a cloth into the Shellac and wipe a thin coat over the surface. Shellac dries in minutes and cleanup is easy ... the rag and gloves can be tossed away! Shellac can also be applied by brush (who wants to clean the brush!?!) or spray (I reserve this for more intricate surfaces, such as a carved mirror frame), but care should be taken to avoid any heavy buildup. Shellac should always be applied in thin layers; if applied too thickly, it can cause subsequent paint layers to crack or even peel away.
Use Fresh Shellac
Pre-mixed Shellac is perishable and has a limited shelf life. Cans are marked with their date of manufacture. Zinsser® Bulls Eye® Shellac, a popular brand in the U.S., uses a date code. For example, let's say a can is marked with the code S95079D. The first number after the letter S is the last digit in the year of manufacture. The second number corresponds to the month. The third and fourth numbers relate to the day of the month. This can was manufactured on May 7, 2019.
Since storage conditions can greatly affect its shelf life, always check the manufacturing date to find the freshest Shellac. Shellac typically expires 6 to 9 months after the date of manufacturer (Zinsser® Bulls Eye® Shellac is guaranteed for 3 years after the date of manufacture when stored properly). To ensure the long life of Shellac, keep the container tightly closed and store in a dry place where the temperature does not exceed 75° Fahrenheit or 23° Celsius. Extreme heat can ruin Shellac in less than a week (don't leave it in your car on a hot day!). There is no need to worry about cold weather; since Shellac is alcohol-based it is unaffected by freezing temperatures.
Clear Shellac is non-toxic and both food-safe (good to know for kitchens!) and safe for use on children's toys and furniture. The clear version is always my go-to choice. The white (or pigmented) version is equally effective, but because of the pigments used to make it white, it is not non-toxic, nor should it be considered food or child safe.
What is Shellac?
It starts in dry flakes, which are dissolved in ethanol to make liquid Shellac, which is used as a brush-on colorant, food glaze, and wood finish. Shellac functions as a tough natural primer, sanding sealant, tannin-blocker, odor-blocker,stain, and high-gloss varnish.
Why would you use Shellac?
Eliminate wood grain from showing through
Stop wood tannins from bleeding through
Eliminate stains from bleeding through (water, grease, etc.)
Eliminate smells like smoke
Use on raw wood if too much paint is penetrating into the wood
Cover wood filler
In most instances, you will not know Shellac is needed until you paint and bleed through, or grease stains come through on your piece. That's ok. Just Shellac over the area (do the entire door front, side panel, etc.), wait for the Shellac to dry, and repaint.