Poplar Added to the Mix

Due to the rain that came in late Monday night and lasted well into Tuesday morning, I had to postpone putting poplar firewood into my solar kiln. When I went out this morning, I noticed that plastic on the roof of my kiln had formed a "bowl" and was holding water as a consequence of the rain. Apparently, I failed to pull the plastic tight when I originally constructed the kiln. Disappointed, I managed to properly fix the roof to hopefully prevent it from holding water in the future.

A few hours ago, I managed to fill the rest of the back rack, with some poplar that I had split during the day on Monday. As a result of the rainfall, the poplar became waterlogged. Hopefully, the kiln will do the trick in drying it out and prevent it from being exposed to the elements.

The back rack is full, as you can see above
Photo by Chris Swanson

Upon adding the split poplar to the mix, I noticed that the white oak is progressing, as far as drying out. Also, I inspected the solar kiln for leaks. Thankfully, there was no way for water to seep in, so that saved me the trouble of having to fix them.



Close up of the white oak
Photo by Chris Swanson



All in all, I believe the kiln is working very efficiently to dry out the firewood. However, the dryer the wood becomes, the slower the drying process becomes. Keep in mind, properly seasoned firewood will retain a percentage of its original moisture. Exaggerated drying of the wood will cause it to burn rather quickly, and hot, and could potentially cause hazards, such as chimney fires. On the contrary, wood that is NOT properly dried out, will cause creosote, in other words, tar from the wood smoke, to build up in the stove pipe and inside the chimney, therefore, increasing the probability of a chimney fire.



Solar Kiln Update

Five days out from the time I first put white oak firewood in my kiln, I checked on it to see the progress, if any. At first glance, I noticed moisture on the inside of the plastic sheeting that covers my kiln, where the sun had drawn out of the split oak. The wood seems to be drying out fairly quick, although the sun isn't as hot at this time of year. Tomorrow I will be adding a mix of poplar, and yellow pine to the kiln for observation.

If you look closely, you can see the moisture droplets on the plastic
Photo by Chris Swanson

I want to see the effectiveness of the kiln, and how efficient it is with different types of firewood. Each type of firewood has a different amount of moisture content to start with so just running the experiment on one certain type of wood, would not produce the results that I'm looking for. However, if you know your wood, you could estimate the amount of time it takes one species of wood to season in comparison to another.

Photo by Chris Swanson

Aside from the sun not producing as much heat during the fall and winter seasons, I believe the kiln is operating proficiently.

Close up of the firewood inside the kiln
Photo by Chris Swanson

As always, I will continue to keep you updated on this experiment as the kiln produces results. If you have any tips or questions, please feel free to leave a comment below and I will respond as soon as possible.

MY ATTEMPT AT A SOLAR FIREWOOD KILN

This past week I built what is, my attempt at a solar firewood kiln.

A solar kiln is a resourceful means of drying lumber or firewood, with solar energy (the sun). The way it works is by using plastic sheeting or glass to draw the sunlight in and intensify the heat, acting as a greenhouse to speed up the drying process of the lumber or firewood. During the day when the sun is out, it works to draw moisture out of the wood. The wood gets a period of rest during the nighttime hours. During those hours the wood gets time to cool down. The next day the cycle starts all over again.
I personally don't know anyone who has one or has used one. I came across the idea somewhere online and to me it made sense, so I built one.

 Above you can see how my "solar kiln" turned out. 

Photo by Chris Swanson.

I completed the construction on the kiln yesterday, and added some white oak firewood, to test the kiln. Since I currently do not have a moisture meter, I'll be conducting the experiment by sight. Being around firewood my whole life has gave me a good sense of judgment when it comes to determining whether a stick of firewood is properly seasoned and dry. I intend to add some pine to the mix as well.

Being that it is almost winter, I don't expect the solar kiln to produce the results that it would during the summer season because the sun isn't as hot.

Side view of my kiln to show the structure.

Photo by Chris Swanson

View of the firewood inside the kiln

Photo by Chris Swanson

My design is a little different than most that I've come across online. Most people install fans to help circulate air. Also it is said that if you paint the inside black, it helps to draw in sunlight and heat. The angle of the roof determines how much sunlight can get in. You will want an angle anywhere from 30-45°. 45° is most commonly used in the winter months.

Click here for more in-depth details about solar kilns if you plan to make one yourself or just want to learn more about them.

I will try my best to keep you updated as to how my experiment turns out. Hopefully it will work as planned. Please do not hesitate to leave feedback, I'd love to know what you think.