Heresy

[Ka Honu]

LQ - Not sure I understand.  I don't use wet wood no matter what I'm cooking in (old rusty grill or whatever) and haven't since long before I had a Bradley.

[Caneyscud]

I'm with the turtle at least partially.  difference is I will/have smoked with wet (green) wood when needed and have not seen the problem that everyone says - and gosh forbid, I've even used softwoods.  A function of camping out where there is little else but softwoods.  However, with turtle on the wetted wood.  It is highly likely the only two things that wetting wood does is produce more steam and delaying the smoking and "burning" of the wood.  As far as producing more smoke - not likely.  Smoking probably doesn't occur until after the water has been boiled off.  What is a good thing about the soaking is the slower raising of temperature within the smoker.  While the water is being driven off, the temp. stays lower.  And when the wood ignites and fire ensues, the temperature can raise rather quickly. 

First off technically wood doesn't burn - it burns indirectly you might say.  What is burning is volatile gases produced by decaying cellulose as wood heats up.  Combine heat, igniter, oxygen and those gases and you have a reaction - fire.  The production of tar - is usually a function of oxygen starved combustion - not necessarily because of burning wet wood and resins. 

Wood sitting in your woodpile is composed of 79% combustibles and 21% water and ash.  Can wood get waterlogged yes, but not in the relatively short times (even overnight) that we are talking about.  It's been proved repeatedly that the dried wood will not soak up much water - probably well less than 5%.  Even if it did here is what happens.  The moisture content of wood has an effect on ignition mainly as a heat sink. The heating up of the water and especially its vaporization (phase change) consume heat energy  . First  the water boils off whether it is free water (soaked) or cell water.  As the water goes through a phase change - water to steam, the piece of wood acts much as a butt - it goes into a stall until most of the water is changed.  The wood first gives up its moisture - the water essentially boils off.  Then at 450°F the wood particles begin releasing volatiles.  The gases can ignite then, however more often the ignition is closer to 600 F.

BTW - I have that book also, but I bought it at a garage sale - did not pay much for it, and it sit on the bottom of a big pile of bbq books - but only because I haven't gotten around to reading it yet.  I'm just not a big fan of sauces and lots of different spices in my bbq. 

[Ka Honu]

How did I know that Caney would come up with a well thought out, completely logical, scientific, and undoubtedly correct response that would leave my head spinning?

[iceman]

I'm jus say'n:  ;D

Typically, fire comes from a chemical reaction between oxygen in the atmosphere and some sort of fuel (wood or gasoline, for example). Of course, wood and gasoline don't spontaneously catch on fire just because they're surrounded by oxygen. For the combustion reaction to happen, you have to heat the fuel to its ignition temperature.

Here's the sequence of events in a typical wood fire:

•Something heats the wood to a very high temperature. The heat can come from lots of different things -- a match, focused light, friction, lightning, something else that is already burning... 
•When the wood reaches about 300 degrees Fahrenheit (150 degrees Celsius), the heat decomposes some of the cellulose material that makes up the wood. 
•Some of the decomposed material is released as volatile gases. We know these gases as smoke. Smoke is compounds of hydrogen, carbon and oxygen. The rest of the material forms char, which is nearly pure carbon, and ash, which is all of the unburnable minerals in the wood (calcium, potassium, and so on). The char is what you buy when you buy charcoal. Charcoal is wood that has been heated to remove nearly all of the volatile gases and leave behind the carbon. That is why a charcoal fire burns with no smoke.


•The actual burning of wood then happens in two separate reactions: When the volatile gases are hot enough (about 500 degrees F (260 degrees C) for wood), the compound molecules break apart, and the atoms recombine with the oxygen to form water, carbon dioxide and other products. In other words, they burn. The carbon in the char combines with oxygen as well, and this is a much slower reaction. That is why charcoal in a BBQ can stay hot for a long time. A side effect of these chemical reactions is a lot of heat. The fact that the chemical reactions in a fire generate a lot of new heat is what sustains the fire. Many fuels burn in one step. Gasoline is a good example. Heat vaporizes gasoline and it all burns as a volatile gas. There is no char. Humans have also learned how to meter out the fuel and control a fire. A candle is a tool for slowly vaporizing and burning wax.

•As they heat up, the rising carbon atoms (as well as atoms of other material) emit light. This "heat produces light" effect is called incandescence, and it is the same kind of thing that creates light in a light bulb. It is what causes the visible flame. Flame color varies depending on what you're burning and how hot it is. Color variation within in a flame is caused by uneven temperature. Typically, the hottest part of a flame -- the base -- glows blue, and the cooler parts at the top glow orange or yellow. In addition to emitting light, the rising carbon particles may collect on surrounding surfaces as soot.

The dangerous thing about the chemical reactions in fire is the fact that they are self-perpetuating. The heat of the flame itself keeps the fuel at the ignition temperature, so it continues to burn as long as there is fuel and oxygen around it. The flame heats any surrounding fuel so it releases gases as well. When the flame ignites the gases, the fire spreads.

On Earth, gravity determines how the flame burns. All the hot gases in the flame are much hotter (and less dense) than the surrounding air, so they move upward toward lower pressure. This is why fire typically spreads upward, and it's also why flames are always "pointed" at the top. If you were to light a fire in a microgravity environment, say onboard the space shuttle, it would form a sphere!

Hmmmm.......... No water  equals smoke I guess.  :o   ;D

[Ka Honu]

Jeez, Pat - now my head really hurts!  I knew I shoulda paid more attention in those science classes!

If flames "point up" on earth and are round in space, how many movies did Netflix send out in the last 13.2 days?

When you comin' back?  We got rum.

[hal4uk]

Huh?  Wood can IGNITE? 
Uh ohhh..  BRB....

[iceman]

Jeez, Pat - now my head really hurts!  I knew I shoulda paid more attention in those science classes!

If flames "point up" on earth and are round in space, how many movies did Netflix send out in the last 13.2 days?

When you comin' back?  We got rum.

Rum??? That was really good rum you had but even better food and company!
Hope to get back over soon to see you folks again.
BTW how did the new wall around the pool turn out?

[Ka Honu]

Wall is good.  Solar (PV) installed but some "finish work" yet to be done.  No more renovations or repairs for a while (I hope).

[seemore]

wow I need a beer
seemore