My furnace grayed are shot. Ok for wood, not coal.
I wish I could buy new ones, but the manufacturer doesn't make
them anymore. I might try to get them cast.
Anyway, if I had grates, we would use some coal.
Wood is ok, but it's not even close when you really need heat.
And coal is so steady.
Get some Osage Orange if you want wood heat. Too much of it will cook a stove or flue pipe.
