No I do not have a BBQ addiction!

[okmulch]

Norm,

I found some lump mesquite at Sam's club the other day and decided to give it a try. It works well, we had burgers on the Weber tonight also.

[Norm]

I've heard good things about that lump, I'll have to get some to try out next time I'm in there.

[D L Bahler]

 We make our own lump, and it's great stuff too.


We built this contraption to burn wood into coal. Actually we built this to make tar, and very nice charcoal is a just byproduct of the process.

That said, I built a brick contraption so that I can cook meat over straight wood. I love steaks cooked over white oak.



Here's the underside, the pipe for the tar to run out is a piece of hickory bark cut off of a large log and let to naturally curl into a tube.

[Magicman]

Now, tell us more about the tar.   ???

[D L Bahler]

The tar is not for eating....

Used for wood preservative, you can make an excellent wood sealer by mixing pine tar and linseed oil, add some dirt or ash or something like that and you have a decent UV-blocking paint.

But by burning coal in a direct-burning pit like this, you get a superior product, but it is a lot harder to do

[beenthere]

Me thinks you missed the question. ;)

How does that pile of sticks and bark pipe give you tar?
Can you explain how it works?

[D L Bahler]

You pile sticks in the basin -its built into a hillside so the natural hill forms one side of the bowl, and the other side is framed in and covered with a LOT of dirt. The bowl has a hole in the bottom which drains out into the pipe.

You stack wood in the thing in a special way, cover it over with straw, leaves, twigs, etc. pretty thick, then cover that over with a lot of dirt. But first, when stacking the wood, you stick a big pole down into the drain hole and stack the wood around it.
you cut holes in the dirt around the base and start fires -you need to have good dry wood or it will be super hard to get it started, and hard to keep it under control once you do. After the whole thing is going good, you pull out the pole to create a chimney through the wood pile, if you timed it right the bottom of the pole should be black with tar.
It is important to keep the fire going at the right temperature, hot enough to boil the tar out of the wood but not hot enough to vaporize or burn it. We are going for a temperature in the 600 to maybe 800 degree range here, the higher the temp the more tar is wasted. But you don't ever measure the temp, you just watch the smoke. If thick billowy smoke is coming out, you're running too hot and burning off your tar. You want lacy blue smoke, with a little bit of steam mixed in.

You need to cut holes through the dirt now and then and close holes at other times to control the burn and try and keep the actual fire in the middle or close to it, and every now and then someone has to climb on top and jump around on the pile to collapse it as it shrinks away -because charcoal is smaller than the wood it used to be.

The tar itself bubbles out of the wood and runs down, and the dirt covering will help to condense any evaporated tar as well. This runs out the bottom and into the tube, to be collected in buckets. Usually you throw out the first bit that comes out, it's mostly water.

And once you burn the tar and water out of a piece of wood, you are left mostly with carbon and a few other chemicals. Charcoal is simply the solid components of a piece of wood, mainly carbon and calcium, after all of the volatile compounds have been driven out of it. When you do this, you produce wood gas, which is tar, methane, and hydrogen, and you want to condense the tar into liquid, or keep it from going to vapor at all.

[Den Socling]

Bahler, it is nothing short of amazing that you know this process. It sounds like an old one that has been passed down for generations. But I wouldn't want to be the one who jumps up and down on the pile! 

I was in Phoenix last week and the stores had their lump supplies on display. I often forget what I am missing by living in a rural area. They had everything imaginable. Apple, mesquite, hickory - you name it. You could BBQ with something different every week.

[D L Bahler]

We sort of revived the craft. It's really old, but all but dead today. Tar making passed out of practice when ships were made of steel and houses were no longer clad all over with wood, and all but vanished when cheaper coal and petroleum tars became readily available.

But having a keen interest in historical craft, we found the need to be able to have a supply of good quality pine tar -and the stuff you can by isn't the same, it's made by an indirect-burning retort kiln, yielding a different tar. We're still far from the old timers, but maybe some day...

[Magicman]

I hope that you will share some pictures next time you get-r-going.  I have seen tar run out of firewood, but capturing it was never a thought.