Slab Wood Fired Kiln

[Sawyer Rob]

OK, i am a retired custom furniture/cabinet maker and i owned my own shop for many years. Over those years, i used a LOT of both, kiln and air dried lumber.

Personally, i found it very hard to tell the differtence between "properly" kiln dried and my air dried lumber. All of the air dried lumber i used, i dried myself down below 20%, by leaveing the lumber on stickers outside. Then i'd move it into my shop to to get below 8 or so %.

Because i always kept plenty of lumber on hand, i had no problem having a stack of lumber in my shop for up to a year before it was used. In fact one of the best tricks i used, was to use the lumber as long shelves! Then aprox once a year i replaced all the shelves with new lumber, useing the dry shelves (lumber) where ever needed.

Today, i'm just a hobby woodworker and i pretty much mill out all of my own lumber, air dry it and build with it and it's still working perfectly for me.

Rob

 

[Dave Boyt]

Part of the issue is just what you plan to do with the wood. There is certainly no point in kiln drying wood that will be used outdoors, such as ramps for loading heavy equipment. The main advantage is that kiln dried wood is pre-shrunk so that the joints in furniture don't come apart when the furniture is subjected to low humidity, such as inside a house in the winter. The finish (such as varnish or lacquer) helps seal the wood and slows down the shrinking and swelling due to changes in humidity, but doesn't stop it entirely. In the old days, they used floating panels that could shrink and swell without cracking. Wood can shrink or swell as much as 10% across the grain but only 1% along the length of the grain (some variation by species), and the old-timers used this in their cabinet and furniture design. Wood does pick up moisture and swells when exposed to humid conditions, which is why some drawers in my dresser are nearly impossible to open in the summer, and some of the kitchen chairs fall apart in the winter. Solar kilns can get high enough to kill the bugs, if they are well enough insulated. Woodweb is a great source of information, and Dr. Wengert, who frequently answers questions on the forum is a world renowned expert in the area. He's one of the great "myth busters" when it comes to dealing with water in wood.

 

[Arbonaut]

This keeps getting better. Especially when you consider the ultimate end use of the wood and the desired qualities.

What was said about the deflection of the wood used as a shelf is true. Adding moisture and heat is the way to bend wood such as the sides of an acoustic guitar or parts of a violin made from one piece of wood but curved. When you dent a guitar or furniture, you can often get the ding out if the cells didn't rupture by using moisture and heat.

Many of the exotic hard tonewoods like Ebony or Rosewood or Cocobolo, Purple Heart, Sappelle are from high humidity regions like jungles and with no provisions for kilns. They can get air dried for a generation before they become something finished. If you used the Rosewood to make a Pool Cue Stick with plenty of laquer, it will remain quite stable. If you used it to make a guitar fretboard, whick takes a very dry finish, it will absorb enough moisture in the springtime to swell more than the nicely sealed Maple neck that it is glued to. This throws the neck, (which is three times thicker) into a back bow. Then the guitar is unplayable until some one adjusts the steel truss rod in the neck to align it.
You guys are makin' this an awsome thread. Can I rate my own thread? Five stars.

 

[Dave Boyt]

5 stars from me! I'm learning a lot, too. Woodcutter, sounds like you're a luthier (not that religion matters :} ). I'm an amateur guitar picker & have built a few stringed instruments, though no guitars yet. I've got some well-aged walnut crotch wood I'm itching to start working with.

 

[Mahindra123]

. Woodweb is a great source of information, and Dr. Wengert, who frequently answers questions on the forum is a world renowned expert in the area. He's one of the great "myth busters" when it comes to dealing with water in wood.

Dave - if this is the same Dr Eugene M. Wengert - he is the man that co-authored the "bible" I mentioned earlier. He is the prophet of kiln drying and I wouldn't even think of putting my years of trial and error experience anywhere close to his knowledge in the art of kiln drying. However keep this in mind - many of us are trying to make do with producing a kiln within the costs we can reasonably afford. Some of us can't even achieve the temperatures in the kiln he refers to, nor the instrumentation he talks about. If you truly want to hear it from the expert, ask Dr Wengert. He KNOWS where you and I often have to guess. He has great advice and leaves nothing to question. We are only sharing advice from what we have gleaned in the past and the posts reflect exactly that.

Enjoy today because tomorrow could get worse.

 

[Mahindra123]

Apologies to Woodcutter

Woodcutter - I apologize to you for taking your thread outside of the realm you intended. I certainly never meant to steal it like I did. As far as your original post - you darn right I would burn slabwood to fire my kiln! Why not? Heat is heat! Despite the EPA's concerns with hydrocarbon emmisions, whether the fuel source used is natural gas, propane, electricity, coal or wood, everyone of these fuels adds to "global warming" with their own inherent problems.

For the rest of you guys - I once heard that a log, laying in the woods, and in it's process of rotting, gives off the same amount of BTU's as burning it. Anyone ever heard this before? I don't know how someone measured that over a 20 year span or maybe it is a fact of physics - I don't know.

Woodcutter, that is how easy I get led astray and off the original topic......Sorry

Enjoy life guys!

 

[Arbonaut]

No complaints here, Mahindra. Woodcutter TV threads have a tangential quality to them. I posted one in the firewood forum about using firewood to smoke deer meat, and guys were posting pictures not only of their roasters, but of home brewing and classic musclecars , etc. We are the content. It's a way of life. Five stars on the meat smoking thread, too.

R. Bruce Hoadley is my favorite authority on wood.

 

[Sawyer Rob]

I would use slabwood to fire a kiln, but it would be direct heat, not a wood fired boiler... In fact i keep saying i'm going to do just that, but it always low on my list and doesn't get done.

Rob