New solar kiln begins

John_Haylow · September 24, 2012, 06:21:15 PM

Wow! That is one nice kiln. You did a fine job. Looking forward to hearing how it works.

John

GeneWengert-WoodDoc · September 24, 2012, 06:41:06 PM

The vents are seldom opened wider than about 10% EXCEPT when drying a stain prone wood or a fast drying wood. Then the vents are wide open and the dryer is used as a single pass dryer (air comes in, past the fans through the load and much of the air goes outside after this single pass) with a small amount of solar heat helping. The RH will be too high with a fast drying wood if the vents are closed. Vents would be closed at the end when low MCs are required.

The VT kiln I designed always uses two layers of covering as this reduces heat losses substantially. Then under two layers you can put a black collector or can just paint everything inside black. Do not let sunlight hit the lumber.

Sawdust Lover · September 24, 2012, 08:11:53 PM

Thats very helpfull Gene. I am buying 2 sheets of 3/8 4x8' steel and will paint it black to lay on top of the wood. I do not have the wood covered right now but will do so first thing tomorrow. Very helpful on the vents too. That has been my hardest thing to figure out is when to open and close the vents. I learned alot from Dr.Brian Bond at Va.Tech but had to leave the class early and was unable to take the entire course. I will reattend it next year so I can learn a bit more about drying. It's a great course and highly recommend it to anyone building a solar kiln.

Ironwood · September 25, 2012, 09:21:46 AM

Gene,

Welcome to the FF. Glad to see you here. I am sure you will enjoy your stay.

Ironwood

MotorSeven · September 25, 2012, 09:36:28 AM

Sawdust....outstanding job...I'm jealous :( :D

firefighter · September 26, 2012, 10:44:43 PM

Great Looking solar kiln .I was looking at the plans for the VA solar kiln but like how you made your 10 feet deep .Could you let me know how tall you made the North wall .

GeneWengert-WoodDoc · September 27, 2012, 07:58:27 AM

It would be best to NOT use the steel as it will act as a heat sink and prevent the kiln from getting as hot as possible. This means that the RH will also be higher. The net effect will be slower drying. Use plywood, exterior glue.

With the wider load, a bit more fan power is needed.

Sawdust Lover · September 27, 2012, 08:34:52 PM

Firefighter, The north wall ended up being 13' tall and the south wall was 3'6" tall. As you can see in the picture the 12' sheets of roofing were 2' to short. I just finished it off with some metal roofing. Gene, thanks again, you saved me $500.00 in steel plates. I will get some plywood painted this weekend. So far the kiln has been heating up 130 deg with outside temps around 77 to 80 deg. So far so good! Welcome Gene! It's good to have you here.

Sawdust Lover · October 03, 2012, 10:32:22 PM

Took out my first load of lumber today. 8) 8) 8) 8) 8) 8% MC and stayed straight as an arrow. Customer comes on Saturday to pick up there 1000 bf of cherry and I'm putting the other 500' in my shop. Now lets see how the 2" walnut does.