Glazing for a Solar Kiln

Clear glazing works much better than translucent white, a solar kiln owner discovers. December 15, 2005

Question
I have just completed the kiln in the picture. I am wondering if I made a mistake by using the translucent white Tuftex Poly Carb instead of a clear Poly Carb. I have had it up to 133 degrees. The weather has been hot here in South Eastern Illinois. Any feed back will be appreciated.

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Forum Responses
(Sawing and Drying Forum)
From contributor A:
A more transparent covering material would be much better.



From contributor B:
Do you have more pictures from the back and inside?


From the original questioner:
The kiln is 12 foot long and 8 foot wide.



From contributor D:
How are you evacuating all the moisture the lumber gives off? Is it wicked off with fans, or do you need to have a dehumidifier?


From the original questioner:
Here is a picture of the inside. I don't have the drop down tarp installed, but the fans are visible at the top, with openings in the tall wall.

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From the original questioner
I changed the glass to clear, and it has made a big difference in the maximum temperature. I understand that to kill the bugs you need to get the kiln to 130 degrees or above. How long must the temp stay at 130 degrees?

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From contributor E:
I built my solar kiln this summer and I am very happy with the results. I used two pair of sliding glass doors for glazing. It faces exactly south. I used two attic fans from a box store and they do an excellent job. My kiln is on skids so when it is empty I can change location. Besides I built it in my pole barn then skidded to the location. When I first set it out it went to 189 degrees empty. I put a load of pine that was previously air dried to 16%. My temp was around 140 degrees. I then closed all vents and raised the temp to set the pitch. It was clear for two days at 75 degrees outside and the kiln reach 160. My temp probe is in the wood pile and the readable digital face is outside. I have one thermometer probe in the top about six inches below the glazing and the other in the middle of the wood pile. It will pick up heat even if the sun doesn't shine. The other day it was 61 and overcast and the inside was 88 degrees. It is amazing. I hope you have as much fun with yours as I do with mine. My capacity is 750 bf. I am located in Central New York State. Also I used a black truck tarp and hung it from the fans down to the wood pile forcing the air to go through the pile. I also operate it with the vents slid open maybe four inches.