Eucalyptus has to much lignin to be much good for charcoal part. I did use cherry wood charcoal, it did work, but did not have much power, about a 5th by guess of store bought black. In a large quantity I did fire off a mortar, and it did go well then. Tried in both Navy colt and long rifle, but as earlier stated not good enough. I have some willow that I will charcoal and see how much difference that makes. I gather the temp for the retort is fairly critical.
Cheers
Gordon
When my Ozzie buddy was into it he played with various varieties of Eucalyptus. He found that two would work up into an acceptable rifle burn rate powder. That was back in the late 1980s and their names escape me.
In his research he found that back in the late 1800s a lot of Australian Black Boy (now known as the Grass Tree) were harvested and shipped to the California Powder Company, here in the U.S., where it was made up into small-arms black powders. The resin extracted from this "grass tree" was used in adhesives and also as a resin in varnishes and lacquers. Imparting a red color.
I would question the idea that the amount of lignin in some Eucalyptus makes it unacceptable in a good small-arms type of black powder. When charred correctly all of the lignin is converted over to other liquid phenolic structured chemicals. The presence of 8 to 10% "oil of creosote" in Glossy Buckthorn Alder wood is the secret to a true "moist burning (Nassbrand) powder.
The problem with a lot of woods is the basic structure of the wood. Under a good microscope the wood looks like bundles of soda straws glued together. It is these tubes that carry water and minerals from the roots up the tree and then sugars back down to the roots. With Oak the walls of the tubes are two "cells" in thickness and the walls of the cells are very thick. With European Black Alder, Buckthorn Alder and White Willow the tube walls are only 1 cell thick and cell walls are very thin. With Black Alder the tubes look more like fine hairs.
This produces an effect my Oz buddy and I used to describe as "grindability". You must be able to break the charcoal down into very small particles. In a rifle burn rate powder about 50 to 55% of the charcoal will be 2 to 20 microns in size. In some 19th century European sporting powders I found charcoal with a portion being less than a micron in size and very little over 30 to 40 microns. This particle size of the charcoal plays an important role in how fast the powder burns relative to the rates of chemical reactions. Combustion reactions. This also has a noticeable effect on how much of the powder combustion residue is left in the bore.
If you look at Colonial U.S. iron production you see the iron furnaces using very strong woods charcoal. Oak and other "strong" wood chars. The charcoal strength being required to support the limestone and iron ore in the charge. If the wood crushes and compacts you could not blow air through the furnace charge. I joked that the best woods for a good black powder are those you would not use in a Colonial blast furnace or in a wood burning stove where excess creosote promotes chimney fires.
The Ozzie and I had to do a lot of work to see why one wood would work while others would not. No single factor determines which is best.
Mad Monk
