I've been lazy and letting the ashes collect

[precaud]

ok...I buy that...except the overfiring part. You are saying this should not be happening if the stove were not overfiring?

No, I am saying that how a grated stove is operated could play a big part in the formation of clinkers. And "overfiring" doesn't mean the whole stove is aglow. The F3 in particular has a startup air control that is supposed to be closed in normal operation. If left open, it will certainly cause excessively high temps at the coals bed and could easily cause clinkers.

When you burn your grate-less stove `optimally' you never see these?

Quite the opposite. I said I've ONLY seen them in my grateless stoves, and only in the front of the firebox, where the hot coals get the most air.

I make a good effort to not overfire my stoves but I do get these clinkers every week or so.

What stoves are you burning?

Are your clinkers brownish and look a bit like particle board?

Basically yes, but I've seen various colors and consistencies...

 

[wahoowad]

I have the F3. I have yet to see a clinker. My ash door seals tightly so no leakage there. I also am very good about closing my startup air control after things have settled in. This clinker you talk about is a mystery to me. Everything will eventually burn down to ash when I let the stove go out.

 

[begreen]

I've only see them when I have been burning hot 24/7 for several days. That was impossible in our F3 with our softwoods.

 

[Jags]

I also get these "clinkers". To add a little info here: I have a Quad Isle Royal (grate in the bottom). I burn as close to 24/7 as I can. I am SUPER cautious about not over-firing my stove (typical stove top temp from 500-650) and I do not run start-up air. Upon observation, in my stove, these clinkers do not start to form until a heavy ash bed is established. If I am "actively tending the fire" like in the evenings or on weekends, I do not notice the clinkers forming. Overnight burns and daytime burns when I tune the stove down for a long period is when it happens. I do not think I am choking the fire, because on a good load, it will maintain proper temps with the air settings used for several hours before the temp starts the downward slope. These look just like previous people have stated. Brownish, almost wafer board like, with a consistency of burnt toast. I have noticed this happening more when I burn elm, then with harder woods like oak or hickory.

 

[budman]

Oh I forgot to add this is 24/7 also.

1% ash is very high. North Idaho logs are maybe 1/20th of that. Pellets are less than 1/4 of 1%.

Thomas

Well even one ton of premium pellets will fill my ash pan even if I stir it up to compress it it's still about a gallon and a half worth

Even that is 6 gallon at pellets. I thought i smelled BS. ;-)

4 cords of hard wood is 18,000 lbs
so i dont think from 18,000 lbs that 50 gallons of ash is out of the question nor BS.

GO ROO!

 

[begreen]

I also get these "clinkers". To add a little info here: I have a Quad Isle Royal (grate in the bottom). I burn as close to 24/7 as I can. I am SUPER cautious about not over-firing my stove (typical stove top temp from 500-650) and I do not run start-up air. Upon observation, in my stove, these clinkers do not start to form until a heavy ash bed is established. If I am "actively tending the fire" like in the evenings or on weekends, I do not notice the clinkers forming. Overnight burns and daytime burns when I tune the stove down for a long period is when it happens. I do not think I am choking the fire, because on a good load, it will maintain proper temps with the air settings used for several hours before the temp starts the downward slope. These look just like previous people have stated. Brownish, almost wafer board like, with a consistency of burnt toast. I have noticed this happening more when I burn elm, then with harder woods like oak or hickory.

This is what they look like in my stove. Just pulled a fresh batch from yesterday's burn.

 

[precaud]

I have the F3. I have yet to see a clinker.

Oh, my dear Wahoo... this whole thing started from what you wrote in the opening post of this thread:

So now I have a good 2 inches of fairly dense ash in the bottom of the stove.

Perhaps I made the mistake of equating that with clinkers. If I did so incorrectly, I'm sorry.

 

[Roospike]

I also get these "clinkers". To add a little info here: I have a Quad Isle Royal (grate in the bottom). I burn as close to 24/7 as I can. I am SUPER cautious about not over-firing my stove (typical stove top temp from 500-650) and I do not run start-up air. Upon observation, in my stove, these clinkers do not start to form until a heavy ash bed is established. If I am "actively tending the fire" like in the evenings or on weekends, I do not notice the clinkers forming. Overnight burns and daytime burns when I tune the stove down for a long period is when it happens. I do not think I am choking the fire, because on a good load, it will maintain proper temps with the air settings used for several hours before the temp starts the downward slope. These look just like previous people have stated. Brownish, almost wafer board like, with a consistency of burnt toast. I have noticed this happening more when I burn elm, then with harder woods like oak or hickory.

This is what they look like in my stove. Just pulled a fresh batch from yesterday's burn.

Yep , thats what i had for 3 days last year , son called them lava rocks ;-) , It would be interesting to find out were that came from. I thought mine was so odd because it only happened one time and the reason for thinking it was the wood to blame.
unknown to me.

Maybe its a stove burning issue. :roll:

precaud , get on it man ! Your not going to let this mystery get you ! :snake:

 

[begreen]

Well, they came from my stove %-P . They are very gritty, feel like sand glued together and are very crumbly.

 

[Roospike]

Well, they came from my stove %-P . They are very gritty, feel like sand glued together and are very crumbly.

As you stated BG , you burn soft wood so what are your thoughts there? The softest i have burned in the last few years is Elm so again , maybe this is the difference?

 

[begreen]

I've never seen this from local fir, alder or hemlock. My guess is trapped sand??? We're only about 1500 ft. from the beach so who knows?

 

[hilly]

BG, those are identical to what I have taken out of my stove recently. I haven't burned enough to speculate why they form, but, as I said before, I have been burning soft maple for a couple of months now.

 

[begreen]

Maybe soft maples are high on silicon uptake? They sure grow fast enough.

 

[colsmith]

We get a few of those crumbly hard lumps in our ash as well, fairly regularly, although I didn't notice any today when I was flinging almost a bushel of ashes on the snowy/icy driveway. If you crush/crumble them up in your hand, they will break up and be ash-like. Hubby has a theory that something oozes out of the wood and clumps the ashes up, sort of like clumping kitty littler ?!? Although I don't go for his theory, I don't have my own theory, and am curious about them. I was thinking maybe it was the dubious wood, like the really old apple that has punky bits. We burn many different sorts of wood, mostly mulberry, willow, box elder, apple, ash, and just a smidge of white birch and pine.

I can't imagine how anyone could burn wood and not empty their ashes?!? We have to do it at least once a week. We have an ash pan, but aren't keen on it, so pretend it isn't there mostly. Used to wait until the coals were mostly dead to clear ashes out, but since it is so cold recently we just push the coals around and take out as much ash as we can. The fire does burn better with some ashes, so we don't feel bad that we leave some behind with that method.

 

[precaud]

precaud , get on it man ! Your not going to let this mystery get you ! :snake:

No, I was punting... it's all yours! I'm in the bleachers now. ;-)