Over the last month or so I have been finding what seems like rocks in the front of the stove. The burned wood is leaving very hard, 1.5 inch size chunks along the front 4 inches of the floor. I rake them to the front like coal and I think they break down eventually, but they keep reappearing too. Not burning anything unique, mostly read oak and some locust. Been burning that mix all winter. Puzzling.
Yep clinkers. I worked at a trash burning powerplant in college and clinker's the size of VW's would fall from the boiler walls, stalling on the grate drives.
Yep clinkers. I worked at a trash burning power plant in college. It would drop clinkers the size of VW's on the grate drives and stop up ash flow
I had some large clinkers in the pellet stove, I called them "clumpers". At my previous house we added large chunks of coal for overnight, those were similar but where white in color.
I get LOTS of clinkers. Many of the trees I burn were ravaged by carpenter ants. Locust and Oak.... my theory has been ant galleries. End of the day it's minerals getting fired like clay....
basically this it's a combination of silica, moisture & other impurities that may be present in the wood or on the surface. Woodstove fireboxes rarely see the temperatures required to create silica solubility, partially because we keep moisture content low but secondarily with airwash on the front door glass - the air condenses the soluble silica into a "glass" with fly ash entrained - making clinkers
I never get clinkers, except for when I burn red elm. I don't know why, but that stuff leaves rocks in the stove like you wouldn't believe.
I wonder if the presence of metal in the wood is a factor? Found 2 metal hanger brackets and a big nail in the last two weeks. Maybe those black streaks in the logs have a different makeup?
I've noticed occasional chunks of residual hard stuff over the years, but never gave it a thought thinking it was just a chunk that was burned with a bit of clay or mud that was inadvertently stuck on a piece. However when some wise guy tosses a beer or soda can into the shop stove, I find strange shaped lumps of aluminum blobs when the fire cools down.
