Slag

[grumpymoe]

this can be moved to the shanty board later, but thought I would see if anyone can come up with the chemical makeup of this slag that is generated from the woodstove....I use seasoned Ash only and the heat is tremendous...(2nd only to oak for btu's).....the coals are always building, but when I go to clean the ash out, there is always these huge chunks of slag that seem to have a silicate base...fragile on the outer edges.....very heavy weight....this piece would weigh approximately 3lbs plus....sitting outside on the cement step in below freezing temps...10 minutes later, its is still too hot to handle with bare hands.....does anyone know the true makeup of this Brick so to speak?......Grump   

[Left Handed Model]

Does your wood have a lot of sand on it? I work with hot top and a lot of sand has silica in it.

[grumpymoe]

No....grateless stove with outer brickwall insulators.....NO sand whatsoevery......every week there's always chunks of this slag in the coals.....I know the proper terminology is slag....but very interested in how this stuff generates from just burning plain old Ash wood....Grump

[reelbigfish]

I've burnt a lot of wood over the years so I thought I'd give a guess as to your
slag.  Different species of wood have different burning characteristics.  Oak burns
with a bed of coals that are like charcoal while the ash wood has a bed of coals
that are more like burning embers.  These tend to smolder toward the end of their burning cycle.  Since you have no grate in your woodburner there is less air from
underneath to completely burn the embers to ashes and the ash bed is extinguishing
them before they can completely burn down.  This combined with whatever moisture
and sap may still be left in the wood is creating these clinkers.  Not a problem it's
just that some ashes are clumpier than others.  The chemical makeup probably includes potash and carbon.
  Just a sidenote on the ash wood.  The state of Michigan found some emerald ash borers here around a year or two ago and have begun an eradication program that
includes every ash tree in the state.  This deeply concerns me as I go up north
every spring to hunt morel mushrooms under huge black ash trees.  Last spring
I saw red paint on these ancient trees, marked for destruction.  There will not be
any ash tree standing once they are done.  I'm not sure how much destruction these bugs would have caused but the logging out of these magnificent trees is criminal.

Ted

[burdo]

beer cans