May 25, 2023
Quite Frankly, if it is your first time dabbling in woodworking, you might be perplexed upon seeing deformed grain in your wood. These deformed grains get usually formed by rounded outgrowth on the tree trunk, characterized by tiny knots from dormant shoots or buds. These knotty wood grains get generally referred to as burl wood or burr. Burls typically form when the tree gets stressed, injured, or infected by fungal or viral infection.
Burl can yield a highly figured wood, desired and sought-after by many woodworkers. Thus, burl wood or furniture with burl wood may fetch a high price. Since burl woods are external growth or knots, they usually form randomly and create denser and stronger wood. Such a block of wood gets prized for its beauty and intricate grain patterns.
How Does Burl Wood Grow and Form?
Trees usually take several decades to mature. Some trees may last for several centuries or millennia. Throughout the tree’s life, it might experience damage, insect or fungal attack, storms, and many other environmental damages and factors that could cause it stress. If a tree gets damaged, it usually responds by healing itself, forming callous tissues that later form burl wood. These callous tissues come out with unique styles and shapes that many of us often admire.
Once a tree gets stressed or experiences injury, it activates its dormant buds, producing random growth, protecting the wood, and preserving its structure. In the process, external burls or knots get formed along the tree’s trunk, branches, and base.
The production of wood burls is a mechanism of survival for the tree. In case of injury, the tree immediately activates its dormant buds as a contingency measure to ensure it can pass its genetic code to the next generation of trees.
Wood burl, of course, emerges from sampling tissue that carries the genetic code of the tree. It is a survival mechanism to ensure the perpetuity of the tree’s genetic code.
However, you may assume that burls are natural growth or offshoots of the tree’s growth. Yet, it is more than that. Besides, you will only find limited numbers of burled wood, and the typical burled wood you will encounter is a live burl that grows along the tree branches. This live burl is quite small relative to other burls.
If you still need clarification on how burls get formed, don’t wallow and fret, for even experts and scientists don’t entirely comprehend how trees produce wood burls. But if you go on reading, you might further understand burl wood.
Different Grain Patterns of Burl Wood
If you have ever tried working with Redwoods, which belongs to the oldest trees in the world, you will notice several variations of wood grain in their woods. You’ll see varying characteristics even in small slabs of wood cut from the giant Redwood, depending on the tree’s actual stage. Below are the few types of burls you will see in Redwood:
1) Lace Burl
You will seldom find a lace burl because it is a rarity. It is arranged in degrees and successive patterns as if it is a bird’s-eye’s burl’s graduated version. It features small burls and curls of grain forming a lace-like pattern. You will also notice that it has unique textures and patterns and rich colors. You will find lace burls in the live burls or crowns of trees. But you will not see them in the stump burl.
2) Bird’s-Eye Burl
Just like lace burl, Bird’s-Eye burl is also rare. It features beautiful patterns with burls that are small and tightly packed. These small and packed burls appear as dark eyes on the wood surface. You will seldom find this burl in Redwood, but you’re fortunate if you can find one, for it is highly prized. You will see this burl often in live burls and crown burls. You will also often find this burl with curly and swirly Redwood.
3) Crown Burl
You may encounter crown burl, which is different from live burls because it doesn’t grow on tree branches and trunks. It often grows adjacent to the roots and stumps of the tree. Moreover, crown burls grow larger than live burls and go on into the tree’s root system. Thus, they are pretty challenging to harvest than live burls.
4) Stump Burl
You will seldom find crown burl nowadays. Thus, many settle for similar-sized stump burls, which look like crown burls. The stump burl doesn’t continue up to the tree root system. Nevertheless, you can see them at the tree base. These burls feature different grain densities and patterns relative to the past stress levels and types they have undergone.
5) Figured Grain
You might think that all wood burls feature figured grain. Yet, there is also a burl called “figured grain.” Well, figured grain burls have wood grain patterns that go beyond the normal straight grain patterns. They have grain patterns with varying intensity ranging from vivid patterns to tiny irregularities. You will quickly notice this in Redwood because of its color variations, specifically in slabs with figured grain patterns.
6) Straight Grain
Straight-grained are those with straight-grain patterns, i.e., patterns that go in only one direction. This grain pattern is the standard growth pattern of grains without any irregularity. They may be bereft of those unusual and exciting figures you will often find in burl wood. Yet, they are still beautiful. Besides, they offer more stability than figured grain patterns, and many love to use them in construction.
7) Curly Grain
If a tree inhabits a slopy ground, it will usually grow a compression or curly grain. As the tree grows, the grain on the tree side, affronting the uphill, tends to be more tightly packed than those facing downhill. Thus, the overall grain pattern exhibits a wavy or curled appearance. Nevertheless, experts also presuppose that this curly grain is determined by genes. Once you cut the wood, you will see unusual colors and unique depths of the wood grain. Redwood with the curly grain gets referred to as “Tiger stripe” or “fiddle-back Redwood.”
Applications and Uses of Burl Wood
The good thing about burls is that they provide woodworkers with highly figured wood, sought after for its natural beauty. Burls, of course, are rare, and for this reason, they get highly prized for their rarity. Burls, however, come in different types depending on the wood species. Hence, they get valued for making furniture veneers, picture frames, inlays for doors, and automobile interior panels and trims. They are also used for woodturning and making household objects.
If you’re an experienced woodworker who has already worked with different types of wood species, you might have seen and worked with burr maple. Burr Maple, of course, is not a distinct species of Maple but just a wood derived from the burl of Maples.
Burl wood is not easy to work using your hand tools. It is hard to turn burl wood because its grains are interlocked or twisted. So, when you work with it, it might chip away in whatever direction. If you’re working with wild-grained burl wood, you will find it hard to split because it is very dense and quite split-resistant. Thus, it is often turned into bowls and mallets.
Types of Burl Wood
Trees can have many burl planks of wood. Besides, many tree species have varying burl wood. Nevertheless, some of the most beautiful and robust burls you will find come from hardwoods. You can use these beautiful hardwoods for making decorative things, furniture, etc. Below are the different burl wood types:
1) Oak Burl
If you’re looking for high-quality burls, you should check the Oak burl, which belongs to the highest quality burls. Its color ranges from reddish-brown to pale brown, though it may have different variations. Woodworkers and manufacturers often use these burls for making wood accessories and furniture.
2) Maple Burl
You will also often find Maple burls originating from Maple trees. Maple, of course, is a common tree species in the Northern Hemisphere of America. Maple burls may have varied colors ranging from light brown to whitish pink.
3) Cherry Burl
You will find the Cherry burl wood with reddish brown color. These wood burls get prized for their durability and beauty because Cherry wood is strong, stiff, and beautiful. It gets often used for making furniture for living room and home furnishings.
4) Walnut Burl
Walnut Burls are a bit expensive than ordinary wood of Walnut. The reason is that they are more beautiful and stronger with varying grain patterns and sizes. Manufacturers of furniture use this for excellent furniture. Besides, these burls get also used for making musical instruments, artworks, and many other applications.
5) Redwood Burl
Redwood gets mostly found in California. These are giant trees with centuries of existence. These trees have beautiful burls with unique textures and veining patterns. Their burls have a red tone and a lighter background tone. They are also very strong and durable. Besides, they are delightful to look at.
Redwood burls can be very large because they come from huge trees. However, you will only sometimes find Redwood burls because Redwood trees are protected.
6) Olive Ash Burl
You will find the Olive Ash Burl unique and lovely. The veneers made of this wood burl are impressive. However, because of its dynamic grain pattern contrast, you need to plan with care the laying out of its wood burl to get the best position for its grain patterns.
7) White Ash Burl
You should check out the White Ash burl if you want a less intense and descriptive wood burl. It has a less complicated and monotone grain pattern which is more predictable. Its color tone is white beige and goes well with stain. Besides, it is a low-contrast burl that you would indeed appreciate.
What Factors Make Wood Burl Unique?
Burls are not formed instantaneously. They grow and develop gradually over the years, within thirty to forty years of the tree’s existence. You will more often see burl wood in colors ranging from deeper chocolate-brown to natural tones.
Because of the unusual and unique grain patterns and textures of burls, they have become a sought-after wood piece by furniture designers. Burls, of course, add beauty and aesthetic factors to furniture and other wood projects.
Burls are imperfections in the grain growth of wood. Yet, despite appearing as imperfections in the wood grain and texture, they are still incredible and gorgeous to look at, and they add a rich texture and pattern to otherwise dull and repetitive grain patterns of wood.
Interior designers love using wood burls because no two are alike. Thus, wood burl makes a statement for any wood project.
The rarity and exquisite beauty of wood burls make them more expensive. Solid wood burl products, of course, have higher prices than those without burls. But if you don’t have solid burl wood, you can always opt for burl wood veneer to enhance your wood project’s design and style.
Burl wood differs from the ordinary type of wood you will see in the market. It is more than that. It has twirls and swirls that you seldom see in the typical wood with common grain patterns. It has highly figured wood grain that could further enhance the beauty and value of your workpiece.
Burl wood, as mentioned above, is the tree’s way of protecting and preserving itself. Yet, in the process, the tree creates something beautiful in its wood which is sought-after by interior designers and artists. Thus, even if it is challenging to work with burl wood, it is a sought-after wood because of its uniqueness and beauty.
Jason is a 40-year-old woodworker, carpenter and author who have been involved in the woodworking and woodcraft industry with 17 years of experience. He is expertise in technical aspects, woodcraft and furniture building projects.