I'm not sure what you're asking so I must not've been very clear.

In the indirect method the fire on the outside of the container cooks the volatiles out of the wood leaving relatively pure carbon. Charcoal.

In the semi-direct method you're burning the wood to generate the heat that will drive the volatiles off and produce the charcoal. Once the wood gets burning well you can close it up and it'll continue to cook off.

In the direct method you just burn the wood and pull the coals out of the fire and extinguish them or use them right then.

In short, yes the fire is converting the wood to charcoal. You will need to break it up if the pieces are too large.

I recommend doing a web search for charcoal making. Looking a few over and reading some and we'll have a better frame of reference for discussion.

Frosty

Any charcoal left by the forrest fire is perfectly good charcoal to use in the forge.
It may need washing if it got dirty---let dry afterwards to cut the number of forge fleas.

I use softwood charcoal out of our woodstove---sift it out of the ashes all winter.

I've used charcoal from a building fire that happened across the alley from my old shop, (electrical fire, I had nothing to do with it; I was out of town that weekend---I have proof!)

I've used charcoal sieved out of bonfire remains in the desert.

The japanese specify softwood charcoal for their smelting and sword forging.

In Iowa we have two kinds of coal , bad and worse, Charcoal is my only option besides gas , check out BP # 338 for one way to make charcoal.
http://www.iforgeiron.com/blueprints-300-400/bp0338-making-your-own-charcoal.html


Jens

or Making Charcoal this is methinks the best tutorial out there. s'got pikkies'n everythin'! uses the volatile gases produced to fuel the retort, clever!

This is a decent how to except for one thing. Don't use cinder blocks for the retort enclosure, they can't take the heat for long.

Frosty