Many modern wood stains & preservatives contain harmful chemicals that can cause allergic skin reactions & permanent respiratory damage!
Without care and failing to follow safety precautions, You can add a much higher risk to unwanted exposure to these chemicals, some woodworkers later in life develop an advection to many wood coating products due to their overexposure,
While these strong chemical products undoubtedly work are they worth the risk when much safer time-tested solutions exist for example Tung oil is made from the Tung tree, which the Chinese have been using since 500 BC to treat wood!
The following is a comprehensive list of natural oil-based stains and a few off-the-wall solutions
#1 Tung Oil
Like a lot of ancient techniques and ideas, the Chinese have been using Tung Oil to give their wooden structures, boats, buildings & furniture protection from the elements and little creatures.
It's is probably the most time-tested method of wood staining in existence and for good reason, Tung Trees from which the Tung oil is produced, primarily grow in the mountains of China. The pure oil is made by cold pressing the seeds of the tree, you can't get more natural than that.
100% pure tung oil is non-toxic, eco-friendly, and can be used for all most everything, including chicken coops, vegetable gardening planters, and raised beds where more modern stains fall short because of the harmful chemicals they contain.
Tung Oil is clear, fast-drying, and enters deep into the wood's grain protecting the wood from degrading and unlike other finishes like linseed oil, it doesn't turn as yellow over time.
It's worth researching what to buy when it comes to Tung Oil as a lot of brands mislabel their products as Tung oil, add thinner, etc... Aim to buy 100% pure Tung Oil to get the full benefits of this ancient stain.
#2 Linseed Oil
Linseed Oil, otherwise called Flaxseed Oil was discovered long ago by early agricultural civilizations to be a great wood stain and a source of food, medicine, and fiber. Even to this day, Linseed Oil is one of the most-used wood finishes the world.
The oil, cold-pressed from flax flower seeds has remained one of the most popular natural wood preservatives, due to its ability to penetrate deep into the porous fibers of the wood, protecting the wood from rotting by sealing the moisture out. Linseed oil is readily available all over the world.
Raw Linseed Oil, processed by boiling, removes protein, improving the drying time and overall finish.
Polymerized Linseed Oil is the best to get as it's non-toxic and faster drying than the Raw Oil, which can take several weeks to dry between layers.
Linseed Oil is great at bringing out the grain of the wood and creates a satin finish but can yellow with age.
#3 Walnut Oil
Juglans Regia, The Carpathian walnut, the Persian walnut, English walnut, Madeira walnut is Old World walnut tree species that produces Black walnut wood and Walnut Oil is derived from the nuts.
Walnut Oil is mainly used for kitchen utensils like cutting boards, wood bowls, and food-related items that come into contact with food, due to its food-safe properties. It is often boiled or heated (polymerized) to improve cure times.
Walnut Oil is less suited for furniture and other items where food is not involved compared to other options written about here.
#4 Pine Tar
Historically used by early boat builders for hundreds of years, many vessels containing Scandinavian sea-bound warriors and their soon-to-be rusty swords would have ended up in Davy Jones Locker without its great sealing properties.
Today Pine Tar is still used for boat building, but its other uses are a little duller such as sealing for fence posts, roofs, utility poles, and other outdoor structures mainly underground, and your odd raised flower bed since the Pine Tar won't contaminate the surrounding soil with toxic chemicals and will safely extend the longevity of your grainy friend.
Mineral Oil is a generic term used to describe a clear and odorless oil. Most Mineral Oil is derived from petroleum and while it may be surprising, it's often regarded as non-toxic, food-safe, and like Walnut Oil great for food-related wood items like chopping boards.
Is a "catch-all" term for any Oil-based wood finish, as they say, "A rose by any other name would smell as sweet"... so read the label on any product branded "Danish Oil" to find out what it's made from its may or may not be non-toxic.
Beeswax Polish is a great addition to any of the stains above, it is very easy to make with just 2 ingredients; beeswax and mineral oil if you would like to make it there are plenty of free tutorials online. Beeswax Polish is food safe when made with food-safe mineral oil and is great on breadboards and other items that need added protection while being safe to eat off.
Black Walnut Husk can be used to stain the wood a dark brown color, that is if you manage to get your hands on some! The husks need to be completely dry before soaking them, if they are not dry you will get a horrid green colour, to make the stain soak the husks in water, and then once the water has turned a dark color you can use it if the stain is too, dark you can light it by adding more water.
Your favorite hot drink! Both Tea or Coffee can be used as wood stains, put on a brew, allow to cool, test on a scrap piece of the same wood, to check the coloring then either add more tea/coffee to the brew or water it down depending if you what to darken/lighten the stain respectively.
Onion Skins can bring even the most staunch person to tears but strangely can also produce a very light yellow to a warmer amber colour based on what wood you apply it. To create the stain just soak onion skins in warm water until you see a yellow colour, then it's ready to use.
A little note about wood and stains
Always test stains on a scrap piece of the same wood, before application to your main project if possible to prevent wanted results.
Softwood like pine will soak up stains and dry much faster than hardwoods like oak and Heart Rimu.
Old dry wood will absorb stains better than water-dense newly cut wood.
I hope that the following information will help you pursue a cleaner, less toxic lifestyle!
If you have your own non-toxic wood stain idea or if you have tried any of the above please share your results with us!