As far as I know, Amber Shellac has been and always will be the classic retro finish for knotty pine. Our grandpas and dads were putting this orange-honey-gold finish on their unfinished knotty pine back in the 1950 and 1960s — and the product is still available today as Bulls Eye Shellac, by Zinsser, which is a Rust-Oleum Company. Shellac is a very interesting product — one of its key ingredients is insect secretions — I think that means, bug poop. (And you know how poop history always interest me.) Read on.
According to Rust-Oleum:
Bulls Eye® Shellac is an alcohol-based solution of lac, a natural resin imported mainly from India, that is available in Clear and Amber tones. Clear shellac dries transparent with a faint, golden cast that is much lighter than oil-base varnishes, while amber shellac has a warm, orange cast that gives a rich, antique-look to woodwork. Bulls Eye Shellac has many advantages over other clear finishes: it’s easy to use, dries quickly, is non-toxic when dry and cleans up easily with ammonia and water.
Digging into the “lac” on the Wikipedia, we learn:
Lac is the scarlet resinous secretion of a number of species of insects, namely some of the species of the genera Metatachardia, Laccifer, Tachordiella, Austrotacharidia, Afrotachardina, and Tachardina of the superfamily Coccoidea, of which the most commonly cultivated species is Kerria lacca.
The above-mentioned families are some of the 28 families of scale insects and mealybugs comprising a large group of about 8,000 described species of plant sucking insects, a few of which produce similar natural products (e.g., cochineal and crimson). Thousands of these tiny insects colonize branches of suitable host trees and secrete the resinous pigment. The coated branches of the host trees are cut and harvested as sticklac.
The harvested sticklac is crushed and sieved to remove impurities. The sieved material is then repeatedly washed to remove insect parts and other soluble material. The resulting product is known as seedlac. The prefix seed refers to its pellet shape. It is used in violin and other varnish and is soluble in alcohol. This type of lac was used in the finishing of 18th-century fowling guns in the United States. Seedlac which still contains 3-5% impurities is processed into shellac by heat treatment or solvent extraction.
The leading producer of Lac is … India. Lac production is also found in Bangladesh, Myanmar, Thailand, Laos, Vietnam, parts of China, and Mexico.
…The use of lac dye goes back to ancient times. It has been used in India as a skin cosmetic and dye for wool and silk. In China it is a traditional dye for leather goods. The use of lac for dye has been supplanted by synthetic dyes. It is used in medicine as a hepatoprotective and antiobesity drug.
Back to knotty pine….I asked Rust-Oleum several questions about their shellac and also for their recommendations on cleaning knotty pine that already has a finish on it. They responded:
Q. Two finishes … and let’s talk “retro authentic”. Rust-Oleum Answer: We offer Shellac in a clear and Shellac in a traditional amber. The amber option is the one that will provide a warm amber-orange-ish color. It’s a personal preference whether or not you prefer the clear finish over the warm, amber finish. The classic Shellac does have that amber (a little orange-ish) tone, which is probably what you are referring to when you call it the “classic” or “patina” look. I would suggest using the amber option for a more retro look, but it’s a personal preference.
Q. Use a wood conditioner first? Rust-O A: If you are using Shellac on unfinished wood, wood conditioner is not needed. Wood conditioner is really only used on wood stains, not clear finishes including shellac.
Q. Is it oil or water-based? Rust-O A: Shellac is cut in alcohol with a little bit of water, but it is not considered water-base. When using a shellac, we suggest wearing gloves as its coating is extremely durable, hence you would not want to get it on your bare skin.
Q. Cleaning knotty pine that already has a finish: Rust-O A: In regards to cleaning, a slightly damp cloth should do the trick. Never saturate the surface with water, instead a cloth is best to avoid puddling. Also clear topcoats should not be cleaned with the following:
- Any chemical cleaners with alcohol as an ingredient – it will may cause the shellac to gum up
- Vinegar – contrary to popular opinion, the acid in vinegar will slowly etch the surface over time and ruin the sheen of the wood finish
- Waxes and oil-based detergents: leave a sticky residue
Note: Clear shellac also can be used for a topcoat for wood trim, furniture and cabinetry. It’s not just for knotty pine.
- Bullseye Clear and Amber Shellac — available in spray can and multiple sizes of liquid cans, from Zinsser/Rust-Oleum.