I’ve had quite a few customers reach out lately, curious about building their own shipping container kiln. It’s a clever idea that offers flexibility, especially for woodworkers handling large drying jobs. As a manufacturer of high-frequency vacuum wood drying kilns, I’ve picked up a few things over the years that might help you build your own container kiln. Whether you’re just starting or already knee-deep in plans, here’s a practical guide to point you in the right direction.
How to Build a Shipping Container Kiln
Building your own shipping container wood kiln involves selecting a container, insulating it properly, setting up heating and ventilation, and keeping an eye on temperature and humidity throughout the drying process. Let’s dive into the details.
Why Build a Shipping Container Kiln?
Building your own kiln gives you flexibility and control, especially if you’re drying wood on a regular basis. Plus, shipping containers are cost-effective and customizable, which is why many woodworkers and businesses prefer them. One woodworker I know dries blackwood planks (30x150x3100mm) in 10m³ batches, and it takes about 10 to 12 days. If you’re dealing with larger batches or different wood types, you can adjust your setup accordingly.
Select the Right Shipping Container Lumber Kiln
If you’re drying larger quantities, a 40-foot container is a solid option. For example, one woodworker planned to dry 4000 board feet of white oak per session and estimated their total cost to be around $30,000. Keep your budget in mind when planning your kiln build.
Another great tip is: refer truck boxes can be a great alternative to shipping containers. Not only are they cheaper, but they’re also well insulated and made of aluminum, which means they’re rust-resistant—a big plus if you’re in a humid climate.
Insulation: The Key to Success
Insulation is critical to your kiln’s success. Without it, you’ll struggle to maintain the right temperature, especially in colder months. One woodworker framed the walls and ceiling, added insulation, and finished it with 1/4-inch plywood painted with silver roofing paint. This setup allowed them to maintain the 140°F needed to kill bugs during winter. If you skip this step, you may find it hard to hit the necessary temperatures for bug prevention.
Install Heating and Ventilation
Your heating system should match the size of your container and the type of wood you’re drying. Some people use electric heaters or dehumidifiers for heat. But here’s a pro tip: if you’re in a hot climate, make sure to install more than one venting fan. Proper ventilation is crucial to maintaining consistent airflow and preventing moisture buildup. Placing fans on both ends of the container will help regulate humidity and prevent issues down the road.
Monitoring Temperature and Humidity
A critical part of kiln drying is keeping an eye on both temperature and humidity. One woodworker drying white oak swears by using high-quality sensors to track temperature and humidity levels. This ensures consistent drying and reduces the risk of cracking or warping your wood. For most woods, maintaining a temperature between 120°F and 150°F should do the trick.
Starting the Drying Process
Once your wood is loaded and spaced properly for airflow, the drying cycle begins. While drying times vary based on wood type and thickness, many find that it takes around 10 to 12 days to dry a batch. Patience pays off here—rushing the process can cause major issues like warping or splitting.
Climate Considerations and Bug Prevention
If you’re working in colder climates, ensuring proper insulation and temperature control is even more important. Several customers have told me they need to hold a steady 140°F for 48 hours in the winter to kill any bugs in the wood. Without this, infestations can develop, leading to costly setbacks down the line.
Final Thoughts: Is It Worth It?
Building a shipping container kiln takes effort, but when done right, it’s worth every penny. Not only do you get full control over your drying process, but you also save money in the long run by avoiding outsourcing. Whether you’re drying blackwood, white oak, or any other wood species, building a kiln can help you achieve consistent, high-quality results.
I hope these insights help you get started on your kiln-building journey. And as always, feel free to reach out if you need more tips or ideas. Happy building!
