I burned a load of waste wood (some offcuts from my work shop, some old fencing, some prunings from the garden) in a steel oil drum incinerator, basically just to get rid. Being an artist, I noticed some usuable chunks of charcoal in the ashes left behind. Some of it was like the regular windsor and newton or rowney type stuff, smooth and velvetty which was predictably "ok". But what I really liked was that some of the charcoal seemed to be only partly "done" and instead of that soft wispy mark that so easily is lost, I was getting a gritty scratchy quality that scored into the paper, almost like an etching, leaving charcoal dust in the scratched lines. The problem is, I dont know how I got that particular gritty sort. I dont know what sort of wood. It could have been ash/oak/birch/beech/alder/larch/pine or whatever shrubs live in the garden(no idea what they are) And the wood just burned until it was gone, I didnt cover it or seal the oil drum. Has any experienced charcoal maker any tips to try and reproduce an "under-done" batch?
charcoal question
- Thread starter mr dazzler
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I use Goat willow trimmings to make "Artist's Charcoal" and just cook them in an old syrup tin that I also use for my charcloth.
plenty of willer around here.....!
When you produce charcoal does it come out soft or hard? And do you cook the wood green or seasoned?
Since I posted the original question, I had an idea. I got a quantity of the charcoal, pesteled and mortared it, then mixed it with cellulose paste (which I've successfully used to make colored pastells using dry pigments) to make a charcoal crayon. I deliberately put extra paste to make the mix harder when it dries out. It just might acheive the same effect of scratching and etching itself into the paper
When you produce charcoal does it come out soft or hard? And do you cook the wood green or seasoned?
Since I posted the original question, I had an idea. I got a quantity of the charcoal, pesteled and mortared it, then mixed it with cellulose paste (which I've successfully used to make colored pastells using dry pigments) to make a charcoal crayon. I deliberately put extra paste to make the mix harder when it dries out. It just might acheive the same effect of scratching and etching itself into the paper
I suspect the gritty nature is more down to the species than the level of conversion.
Generally speaking, the harder the wood then the harder the resulting charcoal, assuming proper conversion (pyrolysis). If the charcoal has been overcooked (normally because it was too hot in the kiln) then it will be more friable and that could give the gritty texture but I would expect the bulk of it to crumble rather than hold together enough to draw with.
Some woods make very smooth textured charcoal, while others are more fibrous or heterogeneous in nature. Willow for example is a stringy wood and makes durable pencil-like charcoal sticks that have a fairly even powdering. Hazel is similar though a bit harder. Oak is an example of a mixed charcoal, where the medullary rays seen in the wood are much harder (they are mostly silica rather than lignum) and I would think should give you the grittiness that you are after. I'm only really familiar with the woods that I make charcoal from (for BBQ and in the forge), so other species and old fences may vary too.
I would suggest using John's method to run some experiments
Use seasoned wood and have it cut to close to size already (if it's being split down from larger logs, then the textures will vary compared to a branch of the same diameter). If the wood is green or too wet, then aside from taking longer to char, it will often 'blow'; that is it will split on the end and likely fall apart.
Partially cooked wood (known as 'brown ends') is normally brown and if the wood is a softer species leaves a brown streak instead of black, at least on other bits of clean wood
hope that helps a bit
Generally speaking, the harder the wood then the harder the resulting charcoal, assuming proper conversion (pyrolysis). If the charcoal has been overcooked (normally because it was too hot in the kiln) then it will be more friable and that could give the gritty texture but I would expect the bulk of it to crumble rather than hold together enough to draw with.
Some woods make very smooth textured charcoal, while others are more fibrous or heterogeneous in nature. Willow for example is a stringy wood and makes durable pencil-like charcoal sticks that have a fairly even powdering. Hazel is similar though a bit harder. Oak is an example of a mixed charcoal, where the medullary rays seen in the wood are much harder (they are mostly silica rather than lignum) and I would think should give you the grittiness that you are after. I'm only really familiar with the woods that I make charcoal from (for BBQ and in the forge), so other species and old fences may vary too.
I would suggest using John's method to run some experiments
Use seasoned wood and have it cut to close to size already (if it's being split down from larger logs, then the textures will vary compared to a branch of the same diameter). If the wood is green or too wet, then aside from taking longer to char, it will often 'blow'; that is it will split on the end and likely fall apart.Partially cooked wood (known as 'brown ends') is normally brown and if the wood is a softer species leaves a brown streak instead of black, at least on other bits of clean wood
hope that helps a bit
Thanks for all the helpful suggestions. I think I'll just experiment with various material. After all its not like its a costly raw material.
Funny you mentioned "brown ends" Dave. I got a few pieces out the ash heap that were knobbly sections of branches (not sure what species but might of been ivy?) but when I drew with it it wasnt a cool grey-black, more like a warm sepia brown. Very beautiful. You could see inside it a mix of black and brown bits.
PS it looks like the charcoal crayons are going to work great. I made 2 plain, 2 with a small amount of clay and 2 with a blue tint. If I'd of had pumice I'd put some of that in
cheers everyone
Funny you mentioned "brown ends" Dave. I got a few pieces out the ash heap that were knobbly sections of branches (not sure what species but might of been ivy?) but when I drew with it it wasnt a cool grey-black, more like a warm sepia brown. Very beautiful. You could see inside it a mix of black and brown bits.
PS it looks like the charcoal crayons are going to work great. I made 2 plain, 2 with a small amount of clay and 2 with a blue tint. If I'd of had pumice I'd put some of that in
cheers everyone
