A few years ago I need a wood drying and heat treating kiln fast. I was in the business of exporting 40 foot shipping container loads of decorative tree branches to various places around the world. It started when we had a big problem with a shipment. The overseas customer received a container load of materials that was infested with powder post beetles boring into the branches.
Long story short, on the next order, we thought we had the problem solved. Only to realize, well into having the material for the next order ready to go, this stock was becoming infested too.
I had thousands of dollars worth of material that was in danger of being destroyed. It also needed to be shipped soon. Previous chemical treatment was ineffective. I needed a way to heat a large quantity of branches to a high enough temperature to kill any insects in them and their eggs.
I didn’t have any kind of kiln. I didn’t know anyone else who had a kiln. I started trying to think of some way to heat these branches up to a high temperature. We are talking shipping container quantities. Even if it took several runs to do them all, it needed to be fairly large to get that many done.
I could build something, but I needed it done now. I needed to start heating them in just a few days before the bugs did too much damage. Also because the customer needed their material soon. I didn’t have time to build something from scratch.
I was looking around for some kind of big room or container I could heat up. Then I remembered, I have an old RV travel trailer from the 70’s laying around that my cousin gave me. My other cousin also had a wood stove laying around. This story really makes me sound like I’m from the back woods. I just happen to have an old RV from the 70’s laying around, and my cousin’s wood stove.
I quickly went to work. I gutted the trailer. Took out the appliances, the cupboards, the counters, the seats, the interior walls, everything. It was just a big empty box. I took the foam pads from the seat cushions, extra bedding etc, put that over the windows and boarded them up from the inside for insulation. I stuffed it into the roof vents and appliance holes.
I took out the window that went across most of the front of the trailer, as they all did back then. Then took a chainsaw and cut out the wall below it all the way to the floor. It was wood and aluminum so wasn’t a problem for the saw.
I took the propane tanks and their mounting bracket off the tongue of the trailer. I then sat the wood stove on the tongue. The big opening gave enough clearance around the stove so the wood in the walls was not too close to it. Probably not far enough pass code, but far enough to hopefully prevent it from catching fire.
Nothing on this contraption would have passed any code. It probably violated every building safety law ever made. As long as it didn’t burn down, that’s all that mattered. The stove was jacketed, made to be an insert. I knew that would help keep things around it from catching on fire.
I took some old garage door panels that my other cousin gave me. This story is really making me sound like I am from the back woods. This is my cousin Darrell, this is my other cousin Darrell. I used those to build a shroud around the wood stove and close off that big opening around it. I bought $90 worth of heat resistant batt insulation to insulate that metal shroud. I believe that was the only money I put into this kiln.
I cut a hole in the top of the shroud above the wood stove to run the stove pipe through.
I fired up the wood stove. It was a relatively small space for a large wood stove. I was hopeful it would get hot enough. I was shooting for 170 degrees Fahrenheit. Hot enough to kill those pesky bugs.
I got it all put together, built a fire, and hoped the thing didn’t burn down. Instead of burning down, it got up to over boiling inside. I loaded it up with branches. It took a while to get up to temperature as the moisture in the branches evaporated out. By the second day, it would be over boiling near the top, and over 170 degrees at the bottom.
It actually worked. But when it was going, it always had this curious hot trailer smell. The idea was to get me by until I could build a real kiln. But this worked so well, I used it for several years. I dried and heat treated many container loads of material in this janky kiln.
Eventually the roof started sagging, the sides started leaning. I don’t think these RV’s were designed to be industrial kilns. I started to realise, that hot trailer smell, may have been the glue in the lamination and elsewhere evaporating out of it. Eventually it got to where it was about to. collapse and noting on it was solid enough to easily repair it.
At that point I bought a 20 foot shipping container and made a real kiln out of it. I put 6 inches of insulation in it, it was so much more efficient than that RV. I could treat so much more material at a time and burn much less wood to get it to temperature. It was also much easier to load and unload.
That RV kiln was such an eye sore. I couldn’t wait to get rid of it. I tore it apart and disposed of most of it. I hope to never ever have to disassemble an RV again after that. I put the trailer frame on craigslist for free and was glad to see it go away.
What’s the moral of this story? I would have saved myself a lot of time and fuel wood if I would have built a real kiln in the beginning instead of this janky thing. Maybe the moral of the story is, just do things right the first time.
But, in that situation, I didn’t have time to do it right, I just had to get something quick. Also, after building and using the janky one, I then had some experience and knew how to build the real one one in a way that would suit my needs. Maybe the moral is, sometimes, you have to do what you have to do.
I will do a video soon and show you my wood fired shipping container kiln.