Live edge slabs!
Ah, those gloriously rustic conference tables and countertops! What could be better?
Well, for starters, how about live edge slabs that LAST?
Who wants a table that becomes bug-infested two years after its beautiful debut? So how do we make sure that our live edge slab furniture stands the test of time? For that, not much beats proper kiln-drying!
In this blog, we’ll provide a thorough rundown of kiln-drying live edge slabs, including an explanation of why proper kiln-drying is so important, the process involved, and 8 ways it improves the final product.
Ready to dive in?
Let’s go.
Terms to Know
Here are a few key terms to understand as we discuss live edge slabs and kiln drying (2 terms that we will also define in the next 2 sections):
- Moisture Content (MC): The amount of water in wood, expressed as a percentage of its weight. For furniture-grade slabs, an MC of 6-10% is usually achievable.
- Kiln Schedule: A specific plan for drying wood, outlining temperature and humidity changes over time.
- Case Hardening: A condition where the outer layers of wood dry faster than the core, leading to internal stresses. Proper kiln-drying prevents this issue.
What Are Live Edge Slabs?
So, what exactly are live edge slabs anyway?
Live edge slabs are large pieces of wood cut directly from a tree. They retain the natural edge, showcasing in the finished tables, shelving, and countertops the unique curves, knots, and imperfections that made the tree a distinct living piece of God’s creation. They have a powerful ability to preserve nature’s artistry, making them a popular choice for homeowners, woodworkers, and designers. Here at River Valley Woodworks, live edge slab furniture pieces remain our top sellers.
But this natural beauty comes with its challenges, as any woodworker will attest. Without proper treatment, live edge slabs are vulnerable to cracking, warping, and even insect infestations. That’s where proper kiln-drying enters the picture.
What Is Kiln Drying and What Other Options Do We Have?
Kiln-drying is the controlled process of removing moisture from wood through the use of a specially designed room called a kiln.
Drying wood can be done in various ways:
- Air-drying (The simplest process for drying wood, but it does not kill bugs.)
- High-moisture kilns (These include the use of steam injection into the kiln.)
- Dehumidifying kiln (Faster drying kilns that run the risk of drying wood too quickly.)
- Vacuum kiln (Another type of kiln that dries wood extremely quickly by removing air pressure, causing moisture to evaporate from the wood faster. Vacuum kilns also run the risk of drying wood too quickly.)
Kiln-Drying vs. Air Drying
As we said, air drying is the simplest process can do everything except kill bugs. Here is a closer look at the pros and cons of proper kiln drying in contrast to only air-drying wood.
Pros of Kiln-drying:
- Speed: Kiln-drying significantly reduces the time it takes to prepare wood for use.
- Consistency: The process ensures uniform moisture levels throughout the slab.
- Pest Prevention: The high temperatures eliminate wood-boring insects and their eggs.
- Stability: Kiln drying makes wood furniture far more stable, reducing the risk of warping, cracking, and splitting. It also helps to prevent the case hardening that can happen under hot summer sunshine.
Cons of Kiln-drying:
- Cost: Kiln-drying requires specialized equipment and energy, increasing overall expenses.
- Skill-Dependent: Kiln drying requires skill. Improper kiln operation can damage wood, causing case hardening or over-drying.
Careful woodworkers have discovered that proper kiln drying is essential for ensuring stability and durability and preventing case hardening in wood products, especially live edge slabs.
In contrast to air drying with its problematic environmental fluctuations, kiln drying uses consistent high heat and humidity to achieve precise moisture levels in a fraction of the time as well as to kill the bugs.
The Kiln We Use
Kiln drying is superior to air drying for all of the reasons listed above. But simply kiln drying wood is not a guarantee of freedom from bugs, however; wood has to be properly kiln dried! That’s why River Valley Woodworks uses a combination of pre-drying (air drying) and high-moisture kiln. We air dry for up to 2 years, properly stacking the wood under shade cloth to prevent case hardening from the hot Idaho sun.
Then we load the wood into our high-moisture kiln.
Spritzers inject moisture into the kiln environment to maintain the humidity levels and draw the moisture out of the wood more slowly. We do not use a dehumidifying or vacuum kilning process since we believe that they may work too quickly and run the risk of case hardening.
Note: Even though bugs will sometimes survive even the most careful kiln drying process, we have developed our process to combine high killing power and careful drying for maximum wood quality. Our process is also very sustainable. We burn scrap wood in our wood boiler that heats the kiln, lowering our electric consumption substantially.
How Kiln-Drying Works: Step-by-Step
1. Pre-Drying (Air Drying):
Before entering the kiln, slabs are typically air-dried to reduce moisture content to about 25%. This step minimizes stress during kiln-drying and prevents sudden shrinkage
2. Initial Heating:
The kiln is gradually heated to a temperature of around 130°F while maintaining high humidity levels (70-80%). This ensures pests are eliminated without causing damage to the wood fibers.
3. Moisture Removal:
Over several weeks, the temperature is slowly increased, and humidity decreased in stages. This gradual process prevents case hardening and ensures even drying.
4. Conditioning: In the final phase, the kiln stabilizes the wood’s moisture content and relieves internal stresses, resulting in a durable, ready-to-use slab.
The River Valley Woodworks Method and Kiln-Drying Schedule
At River Valley Woodworks, we’ve fine-tuned our kiln-drying process to perfection. Here are the main things we focus on during the 4 stages:
- Extended Air Drying: We air-dry slabs for up to 24 months to bring moisture content below 25%.
- Lethal Bug Treatment: During the first week in the kiln, we heat the wood to 130°F for 24 hours to eradicate any pests.
- Gradual Drying: We carefully adjust temperature and humidity over 6-14 weeks, ensuring even moisture removal and preventing damage.
- Careful Stabilization: For the last two weeks, slabs are dried at 100-125°F and 50% moisture. This gradually lowers the internal wood moisture content to a stable 6-10%.
Finally, we carefully test the lumber when unloading. This meticulous process guarantees that our live edge slabs are not only beautiful but also durable and ready for any project.
Why is kiln-drying especially important for live edge slabs?
Live edge slabs are often thicker than normal wood and contain more sapwood than standard lumber, making them especially prone to uneven drying and pest infestations, especially when they are only air dried.
Not to mention that it takes a LONG time. To properly air-dry 3-inch hardwood slabs takes approximately 3 years – an inch per year!
8 Benefits of Kiln-Drying for Live Edge Slabs
Here’s a recap of why properly kiln-drying wood is worth all of the trouble.
- Pest-Free Wood: Eliminates insects and eggs, ensuring a clean product.
- Durability: Reduces the risk of cracking and warping over time.
- Enhanced Stability: Uniform moisture content prevents movement in the finished piece.
- Reduced Weight: Kiln-dried wood is lighter and easier to handle.
- Improved Workability: Easier to cut, shape, and finish.
- Better Adhesion: Glues and finishes bond more effectively to kiln-dried surfaces.
- Longer Lifespan: Properly dried wood resists environmental changes.
- Superior Aesthetics: Brings out the natural beauty of the grain and edges.
Beautiful, durable wood doesn’t happen by chance. Careful kiln drying makes all of the difference.
Tips and Reminders for Kiln-Drying Success
The right habits very important. Here at River Valley Woodworks, we try to follow these 4 points every day of the kiln-drying process:
1. Be Patient: Although it is tempting, we try not to ever rush the process since this can lead to irreversible damage.
2. Monitor Conditions: We use accurate, up-to-date instruments to track temperature and humidity – every day.
3. Choose the Right Method: We will vary our kiln schedule slightly to match the type and thickness of the wood.
4. Inspect Regularly: We regularly check slabs for cracks or other issues during drying. We also inspect all of the wood at unloading.
Wrapping It Up
Proper kiln-drying is the unsung hero of durable, stunning live edge slabs. And now you know why! From eradicating pests to enhancing stability and beauty, kiln-dried slabs have become the gold standard in woodworking. By investing in this critical process for your live edge slabs, you’re ensuring that your high-end, rustic furniture will remain beautiful for years!
Get in Touch Today!
At River Valley Woodworks, we’re passionate about crafting high-quality, kiln-dried live edge slabs for your home or office. We even warranty our slabs (free slab replacement) to make sure that you are satisfied!
Visit our beautiful website today to see all of the possibilities for yourself!
You really CAN transform your space and bring your vision to life!
Contact River Valley Woodworks today for a consultation or to browse our inventory of kiln-dried slabs. Let’s create something extraordinary together!