Making the firebox smaller

[EatenByLimestone]

I'm sure we've all seen somebody suggest making a small fire in a large firebox. When I've tried this, I've had a hard time getting the firebox hot enough for secondary action. Maybe my definition of small is different from other people's. Does anybody have experience making the firebox smaller by adding more firebrick to it? How did it work for you?

 

[Backwoods Savage]

You should get plenty of answers here Matt as I remember several times folks discussing this very thing. As I recall, it worked well for most.

 

[Cynnergy]

Looking forward to the discussion on this post. I have to keep the air pretty open on my small fires to get a clean burn, but my wet wood isn't helping.

 

[dafattkidd]

Hey Matt,
I have a similar sized firebox as you and I don't seem to have this problem. I've seen other similar threads as Dennis mentioned, and honestly half expected to have to do this when i upgraded to the larger unit. But I've never had this problem. You're a seasoned wood burner so I'm sure this isn't helpful, but I'll tell you what has worked for me. I have the most success with quick hot fires if I build the small-medium splits tall. When i have a small amount of wood in my firebox and it's in a small concentrated area it seems to give me a good blast of secondaries and burn cleanly. I also use a lot of kindling to ensure the firebox temps crank. It essentially burns the same as a larger fire, but much shorter. Obviously everyone's set up is different, but this is what works for me in the Oz.

 

[Seanm]

Hey Matt,
I have a similar sized firebox as you and I don't seem to have this problem. I've seen other similar threads as Dennis mentioned, and honestly half expected to have to do this when i upgraded to the larger unit. But I've never had this problem. You're a seasoned wood burner so I'm sure this isn't helpful, but I'll tell you what has worked for me. I have the most success with quick hot fires if I build the small-medium splits tall. When i have a small amount of wood in my firebox and it's in a small concentrated area it seems to give me a good blast of secondaries and burn cleanly. I also use a lot of kindling to ensure the firebox temps crank. It essentially burns the same as a larger fire, but much shorter. Obviously everyone's set up is different, but this is what works for me in the Oz.

Yup I did this tonight minus any kindling. My timing wasn't right for a full load so I split 2 mid size dry lodgepole pine rounds (making 4 splits) and put them in the stove 2.5 hours ago. I had 650f IR stove top temps at the collar for awhile, now ive raked the coals forward and will do my night time burn soon. 22c upstairs and -22c outside! What kind of wood are you burning and whats the moisture content on a fresh cut split? I have no problem getting hot temps and a clean burn like dafattkidd said off a few smallish splits. Never tried what you are suggesting so look forward to hearing what people say who have tried it. Like dafattkidd said you are a seasoned burner so there might be a bigger problem than the wood that im not taking into consideration. Like you say maybe your definition is different than mine. I loaded on a raked forward bed of coals with stove top temps of 375F and had good secondaries within 10 minutes or so,,, different stoves though.

 

[EatenByLimestone]

I think my issue comes from having 2 radically differently sized stoves. The Century has about a 1 cu ft firebox and the Englander, well, 3.5x that. I can't seem to get the Englander to run cleanly on an Century sized fire (couple of splits) but that really isn't an issue due to the Englander's placement in the basement. Once I get it hot it stays hot. This thread is about the Century.

The Century is in an exposed 400 sq ft cabin. Over Thanksgiving it successfully heated the cabin when the temp got down to 9 degrees and I'm very happy with that, but burn times were fairly short. If I upgraded the stove, and I'm not sure I'd want to do that, there's a good chance I'd cook myself out of the cabin on a 40 degree day that needs a touch of heat in the cabin, but not 2 cubic feet of steel stove in a 200 square foot room. And to be honest, the cabin will be used more at 40 degrees than at 9. The other side of this is at 9 degrees the cabin was already heated up so I was just holding the temperature. If I was to walk into a 9 degree cabin I might not be as happy with the stove. This winter I will try that, but I haven't yet. It has yet to be tested with heavy wind also. The cabin also sees -15 or so 3 to 4 times a winter and I know that is past pushing my luck with the stove. I doubt I'd be up there then though. I'm not that into ice fishing to need to be fishing at that temperature.

If I were to replace the Century, I'd have to figure out a way to make a small fire in it burn cleanly for the 40 degree days. Lining the bottom of the firebox with a layer of firebrick would pick the fire up closer to the secondaries so they would light off quicker and give me a smaller firebox so I would probably only be heating a stove around 2cf to around 2-300 degrees at the surface. I've contemplated adding mass to the Century in a number of ways, but that would only be slowing the release of the heat and I would still be limited by the small firebox. A cat stove is I've probably a simple answer to this issue, but then training my wife to use a cat stove might be asking for too much. She's a very smart woman, but she'll block the oddest things out and call them too complicated. When I started burning wood again as an adult I had an early cat stove. The stove probably worked fine, but with the crappy wood I had it was a chore. I think that soured her on the experience.

 

[branchburner]

I took my stove from 2.2 cf down to about 1.5 cf with extra brick one fall, to see if I could get get a quicker secondary combustion with a smaller fire. It did seem to work. My stove is a downdraft, but I do recall seeing someone with a tube stove doing something similar.