# Double Chamber Kiln



## gvwp (Aug 22, 2013)

I've outgrown my first kiln so I am building a double chamber kiln to add capacity and flexibility. The new kiln will have two identical size chambers with separate heat exchangers and controls. 2 X 6" frame construction. Each chamber will be 22' wide, 10' deep and 11' high. As with my first kiln these will be heated with wood scrap burned on a commercial size outside wood burner so heat is very cheap. Each chamber will have four large air movers so just a little electricity every month dries the wood. The kilns are located on the end of the saw/shop building. Here are a few pics of the progress.

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## gvwp (Aug 22, 2013)

A couple pics of sawing the 2 X 4 and 2 X 6" framing lumber for the kiln.

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## Kevin (Aug 22, 2013)

Which wood burner do you have or is it DIY? I'd like some details on that if possible. Hope you keep this thread updated.


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## gvwp (Aug 22, 2013)

Kevin said:


> Which wood burner do you have or is it DIY? I'd like some details on that if possible. Hope you keep this thread updated.



Its made by Hawken Energy (http://hawkenenergy.com). Large unit. 81" firebox. 650 gallons of water. Two water pumps. I burn our slab wood and cutoffs almost exclusively. 8 and 10' log slabs can be cut in half and thrown in. Green, rain soaked, snow covered, dry. Doesn't seem to matter. Takes a lot of wood in the winter though. If we had to buy wood it would not be feasible. Can take a pickup load of wood a day in the winter with everything running. It heats the house, kiln, shop, saw building and all the hot water.


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## jimmyjames (Aug 22, 2013)

Now that is self sufficient right there!


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## gvwp (Aug 28, 2013)

A bit more progress today on the kiln project. Got walls up and roof on one side. Floor is poured on one side. The other side has to wait for the water lines from the furnace to be installed. Its coming along. 

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## jimmyjames (Aug 29, 2013)

Dang you'll be able to dry a ton of wood now!


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## jimmyjames (Aug 29, 2013)

Is the header above the door a microlam or is it a piece of channel iron? Hard to tell in the pic


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## Kevin (Aug 29, 2013)

It's a glulam Jim. Looks like two with plywood sandwiched between.


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## gvwp (Aug 29, 2013)

Yes. Kevin is correct. Its two LVL beams with plywood between. Very strong. These are required because of the 22' span. This will bring my total capacity to around 15000bf per month. More importantly it allows much more flexibility with cycle start and end times. Should be much quicker getting customers' wood back to them no matter where we are in cycles.


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## jimmyjames (Aug 29, 2013)

Dang that's quite the work load there Dave, are you still thinking about upgrading your saw?


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## gvwp (Aug 29, 2013)

jimmyjames said:


> Dang that's quite the work load there Dave, are you still thinking about upgrading your saw?



Yes. Every day. Problem is its just not a simple saw upgrade. For me to update means a building expansion, material handling, and the biggest hurdle an electric upgrade. When I upgrade I'm going all electric so I can shut the doors in the winter. There is no 3ph power in my area so I either have to convert it or generate it. Both options are expensive. In all about $130K is needed for that upgrade. The ole LT70 is worth about $35K of that $130K so one day at a time until then.


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## jimmyjames (Aug 29, 2013)

Same where we are, 3 phase just brakes the bank, and buying a big enough phase converter is too expensive, the good thing about 3 phase is that there's a lot and I mean a lot of cheap equipment to be had since most home owners with small shops don't have 3 phase, a ton of big jointers, planers, sandersetc go for cheap . Your lt70 is still nothing short of a beast, that's a pretty large saw. It would benice working indoors in the winter with the heat on, are you going to put a log conveyor through the side of the building?


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## gvwp (Aug 29, 2013)

jimmyjames said:


> Same where we are, 3 phase just brakes the bank, and buying a big enough phase converter is too expensive, the good thing about 3 phase is that there's a lot and I mean a lot of cheap equipment to be had since most home owners with small shops don't have 3 phase, a ton of big jointers, planers, sandersetc go for cheap . Your lt70 is still nothing short of a beast, that's a pretty large saw. It would benice working indoors in the winter with the heat on, are you going to put a log conveyor through the side of the building?



A 20 ft log deck. Open the overhead door and load the log deck and shut the door. A 20 ft deck should hold enough logs for a couple hours milling if running large logs. Incline conveyor to transfer deck. Pass through to a green chain. Edger/rip saw for edging and/or cutting wide boards into multiple smaller widths. Also looked at a couple slab saws including the Pendu but haven't made a decision. This would be at the end of the line so if nothing is touched the slabs and waste boards drop into the auto slab saw and are cut into firewood lengths and go up a conveyor out of the building. Will be a great setup but wow. Break the bank.


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## jimmyjames (Aug 29, 2013)

Do you burn your sawdust? There must be mountains at your place.


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## gvwp (Aug 29, 2013)

jimmyjames said:


> Do you burn your sawdust? There must be mountains at your place.



No not often. Loading sawdust into the furnace is a pain and it doesn't offer much heat for long. There is enough scrap generated from the slabs and cutoffs to feed 50 furnaces the size that we have so the cutoffs and slabs are used almost exclusively. During the winter months firewood is sold although last year I just didn't have any time to put into the firewood like in previous years. This is why I would like to install the slab saw to automatically cut the scrap into sellable firewood.


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## gvwp (Sep 24, 2013)

The kilns will be done soon. Floors are done. Rough electric is finished. Insulation is almost done. Installing the doors is the next big step. Here are a few pics of the progress.

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## Mike1950 (Sep 24, 2013)

Going to be nice!!!!!


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## Treecycle Hardwoods (Sep 24, 2013)

is the osb going to be your wall material or will you be coating it with something?


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## gvwp (Sep 24, 2013)

Treecycle Hardwoods said:


> is the osb going to be your wall material or will you be coating it with something?



7/16 OSB. It takes a beating but has done fairly well in my first kiln. The first couple cycles dries everything out beyond the original MC but it doesn't seem to breakdown or degrade the OSB. We will put the reflective insulation on the exterior part of the ceiling. Helps radiate the heat back down and adds a little R factor to the ceiling as well.


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## Treecycle Hardwoods (Sep 24, 2013)

gvwp said:


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nice!! I have been building my own double kiln only smaller {(2) 1000 BF chambers} and I used hardboard for my first chamber and painted it with an exterior paint after caulking all of the joints. I have 2x6 walls and 10" of insulation above it. Hopefully it keeps up to speed this winter. 

Glad to see your project coming along. Thanks for sharing.


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## gvwp (Sep 24, 2013)

Treecycle Hardwoods said:


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I used 2 X 6" construction on the exterior of this project as well. 2 X 4" just wasn't enough on the first kiln. I also have 10" of insulation above. We don't have quite as cold of winters down here in Indiana as you do in Wisconsin but its fun to watch the steam rising from the kiln on a 5 degree morning when the kiln is at full temperature.


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## Treecycle Hardwoods (Sep 24, 2013)

gvwp said:


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Sometimes a foot of snow will ruin mornings like that for me:dash2::dash2: sometimes its worse!! 12-16" in one night has happened more than once also In addition to the 10" of insulation I have 18" buffer zone between where the insulation ends and the roof. I put a ventilation fan in the buffer zone to kick in at 120* if it gets to hot during the summer. Only down side to my kiln is the doors they are 2x4 construction. I jammed them full with the highest R rating insulation I could find. I was concerned that the excess weight of a 2x6 door would take it's toll on the hinges over time. If they seem to be holding up I may take them off and put on a 2x6 later on.


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## gvwp (Sep 24, 2013)

Treecycle Hardwoods said:


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I bet all that snow does put a damper on activities! Fortunately we get very little snow around here but lots of cold air. Too far away from the lake to have any affect and not far enough south to get much help from the gulf except on large storms. 

I'm putting vents in the top to vent the hot air. All that hot air causes a lot problems in the winter. The buffer zone various from almost nothing on the ends to about 3 feet in the center due to matching the existing building pitch. 

Doors are always a problem but my others were 2 X 4 construction. While the insides of the doors are pretty trashed after running for 5 years the outsides are in fairly good shape. My seals have also lost some of their sealing ability and should be replaced but all in all I feel I certainly have gotten my moneys worth out of the old kiln. Hopefully with the improvements made on these current chambers they will be more efficient and I get longer life out of them.

Do you have any pictures of your setup? I would like to see it.


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## Treecycle Hardwoods (Sep 24, 2013)

gvwp said:


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Next time I open it up for a swap I will try to remember to snap a few pix. I run an EBAC dehumidifier nothing to fancy. When I poured the concrete for mine I put a PVC pipe 4-5 feet into the ground to drain the water off the kiln automatically. We have lots of sand in the area (360 feet of sand under my house before we hit water for the well) So far I haven't had any problems. I will know how good it really is here in a few months when winter sets in. I have always found my air leaks by ice build up at the leak points.


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## gvwp (Oct 10, 2013)

Putting the finishing touches on the new kilns. Still have to install the heat exchangers and thermostats but its basically ready to go when that is complete. Here are a few pics.

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