We like oil finishes for our projects. A finishing oil is a vegetable oil we use to finish off a desktop or shelving. They are a historical wood treatment, having been used for centuries for the protection they offer against weather and moisture. Application is easy, simply wiping on with a clean cloth, and the effect is quite beautiful.
While varnish offers greater resistance to water, heat, solvents, and other chemicals and seals the surface better, we do like oil finishes very much.
Oil finishes should be applied liberally until the wood stops absorbing it. Rub it firmly into the wood with the heel of your hand, working along the grain. Wipe off any excess after the wood has stopped absorbing it. Oil finishes will protect the wood and bring out its natural beauty. It will also revitalize older wood and bring old pieces of furniture back to life.
Oil finishes are common for furniture and even kitchen utensils. Oil finishes are eco-friendly, non-toxic, and food-safe. They are easy to apply, easy to repair, and will produce a more textured grain than other wood finishes.
As regards using an oil finish on outdoor furniture, it will offer protection for a long time. Oil finishes, distinguished from synthetic (remember that oil finishes are vegetable-based) that will sit on the wood’s surface, will penetrate the wood, and prevent water from seeping in.
In preparing to write this article, we even found a DIY wood finish suggestion of canola oil and vinegar that people have sworn works well. We’ve never tried this before and have no idea whether it’s a good idea, but we might try it sometime on a piece of scrap wood just to find out.
Traditional oil finishes for wood include Danish Oil, Tung Oil, Teak Oil, and Linseed Oil. We’ve written about each of these in past articles, and each is linked to those previous pieces in case you want to check them out.
Woods Used For Outdoor Projects
When we think of woods for outdoor projects, the first two that come to mind are teak and cedar. We’ve also written about using white oak for outdoor furniture projects.
Teak is a very desirable wood for outdoor furniture because it is able to withstand even the harshest of year-round weather conditions. It can remain outdoors all year and hold its natural beauty with yearly cleaning and the application of teak oil (not made from teak-tree oil) or Danish oil (made from linseed oil, rosewood, or tung oil) treatment.
Cedar is an equally excellent choice for outdoor furniture. Although it is a softwood, it is very strong and durable and will not warp or sag. It’s also less expensive than teak and lighter than other outdoor furniture wood choices. Some species of cedar are also naturally resistant to insects and rot.
White oak, like teak, is a hardwood. It’s beautiful and strong and is a close-grained wood that is virtually impervious to water, making it another good choice for outdoor furniture. It’s also strongly rot-resistant and is used in boat building.
All three of these woods take oil finishes well. It might seem counterintuitive to suggest that woods that already have some natural resistance to weatherwear, rot, and insect damage, it certainly does not hurt to apply a finish to enhance that natural protection.
Which Oil Finish is Best for These Woods?
In the order presented, we’ll address teak first. While teak oil is not made from the teak tree oil, it was developed for treating teak. Teak oil is composed of linseed oil, tung oil, mineral spirits, varnish, and UV inhibitors.
Tung oil, by the way, is made from an extract of tung tree nuts. It’s a naturally drying oil that gives wood a transparent and glossy appearance. It beautifies the wood, offers excellent protection, and is eco-friendly.
Teak oil was developed to offer a finish treatment for teak wood, and thus the name. Teak wood can dry out and become gray from exposure to sunlight (those pesky UV rays). While teak wood is already oily, it can still be affected by exposure to the elements, so teak oil was developed to brighten it up with a yearly application.
Teak oil works as linseed oil does to nourish dry wood grain, and linseed oil is also a good choice for outdoor furniture as a yearly treatment. Boiled linseed oil soaks well into the wood to act as a preservative, offering protection from heat and water, although it is not waterproof. The advantage of teak oil over linseed oil is that teak oil provides protection against UV rays.
Linseed oil is vegetable-based and made from flax seed. Boiled linseed is raw linseed oil that has had superheated oil passed through it with chemicals (metallic drying agents). The result is a boiled linseed oil that dries in a fraction of the time of raw linseed oil.
In an earlier article, we wrote of boiled linseed oil being a good choice for an oil finish on cedar. It penetrates deeply into the wood and enhances its beauty and its resistance to heat and water, although it is not waterproof.
It is a clear finish that is both durable and quick-drying. It’s easy to apply and provides protection against heat and water. It’s also inexpensive and gives your wood an aesthetically pleasing appearance on already beautiful wood.
White oak, a hardwood with a tight grain, takes boiled linseed oil very well. It is already a wood virtually impervious to water, although that is not the same thing as being waterproof.
The application of boiled linseed oil is a good choice for white oak. Hand-rubbed into the wood, it creates a beautiful finish that allows the natural grain to show through. After drying and curing, a top coat of polyurethane, varnish, lacquer, or even a marine varnish, brings it into the waterproof category. Remember – we did say white oak is used in boat building.
Does Teak Oil Work Well With Cedar?
Teak oil is a good choice for indoor cedar furniture for all of the reasons we’ve mentioned about teak oil. It is a bit of a mishmash of oils – linseed, tung – and other ingredients. Originally developed for teak wood, it can also be a good choice for cedar.
It will enhance the beauty of already beautiful wood and provide protection from heat and moisture. Indoor furniture is not going to be rained on or exposed to harsh elements, and cedar indoor furniture does not need the degree of protection it needs when used to build outdoor furniture.
While teak oil does offer good protection, it has the advantage over boiled linseed oil in that it contains elements that will offer protection from the sun’s UV rays. UV radiation damages wood fibers, and if left long enough to do its damage can cause wood to crack or warp. Outdoor furniture will eventually fail, although not for a long time, after prolonged UV ray exposure.
So, the short answer to the question is that teak oil can be used on cedar, and it’s also a good choice to provide enhanced protection from heat, water, and UV rays.
However, it may also not be the best choice. If you want a greater degree of protection from water damage, there are other products that will serve you well. A spar varnish could be that extra measure of protection, although it also leaves a visible film coat on the cedar. Spar varnish was developed to protect the spars that support the sails on boats, and thus its name.
Staying with a marine theme, you also have a product like Thompson’s Waterseal or Ready Seal Natural. These are topcoats that can be applied over teak oil to offer a waterproof seal to the cedar.
The fellow in this video offers some additional thoughts on the use of teak oil on his cedar furniture that are worth considering. His furniture also looks lovely in his backyard.
If you decide to go simply with teak oil (or tung oil or linseed oil), plan to apply a yearly coat to ensure a continuation of protection. It will keep the cedar looking fresh and new and prevent it from graying in the elements. It’s easy to apply and dries quickly, and the annual treatment will prolong the beauty of the wood for its natural life as furniture.