Crawford Treasure 12

Thanks Paul. It does draft like crazy. With my other stove I had to add several elbows and more pipe to slow it down enough to burn overnight as well as keep the mpd as closed as possible and shovel on a few scoops of ash to slow it down. The previous setup I had the stove in it would burn 12 hours no problem, with the damper about halfway and no ash. This secondary over the fire air thing is new to me. How do you recommend that I use it? I had it open because it seemed to make a visible difference in the blue flame activity. The more I had it opened, it seemed to be burning the gasses better and it seemed that I could feel more heat coming off the upper part of the stove. I need to get an infared thermometer so i can accurately measure the temps.

I should also mention that the load door where the secondary is is not airtight at all. There is an interesting set of notches on the latch for the door that allow you to either have it fully closed, a bit open, and a bit more open. When I open the door, even when the secondary is already open, I do it slowly because I can hear the stove heating up, ie clicking sounds from the metal expanding. At least i think that's what it is.

oldschoolhouse wrote: ↑

Wed. Jan. 23, 2019 9:45 pm

I should also mention that the load door where the secondary is is not airtight at all. There is an interesting set of notches on the latch for the door that allow you to either have it fully closed, a bit open, and a bit more open. When I open the door, even when the secondary is already open, I do it slowly because I can hear the stove heating up, ie clicking sounds from the metal expanding. At least i think that's what it is.

What was considered "air tight" back when that stove was built is nothing like what we think of with modern stoves with gaskets. But, the stoves were designed to work with it. And that small amount of air leakage does help reduce the chances of a puff-back after putting in a fresh batch of coal.

The clicking sounds might be because it's cooling down. When you open the door it lets in a lot of cold air that gets quickly sucked into the stove pipe. My base heater stove pipe makes those little clicking noises ( like there's mice scampering around in there) when I put it back into base heater mode after I've had the dampers open and it's been getting the pipe very hot. And that's just with the cooler exhaust from the base chamber until it heats up again closer to the pipe temp. The air through the open loading door is likely even cooler.

I'm just amazed that with that size firepot (BTU output), and with that much secondary air, plus a back pipe extracting even more heat from the exhaust, that it is not putting the fire out due to slowly reducing the draft strength. Must be a really good chimney system you have there. There's guys who'd give a ton of coal to have a chimney that can draft that well.

Paul

Well that makes sense, I was thinking about that all backwards. How is the secondary air supposed to be used? I understand that it lets air in to help burn the gasses. I suppose i will just have to tinker around and see what works the best. I shut it down to half for the night and we will see what the morning brings.

Wow that's a pretty stove I like how slender she looks and the design in the front. Awesome work. Congratulations on the whole project from finding it to the toasty house!

oldschoolhouse wrote: ↑

Wed. Jan. 23, 2019 10:19 pm

Well that makes sense, I was thinking about that all backwards. How is the secondary air supposed to be used? I understand that it lets air in to help burn the gasses. I suppose i will just have to tinker around and see what works the best. I shut it down to half for the night and we will see what the morning brings.

Many of these old oak stoves were meant to burn wood or coal. If you burn wood you use more secondary air than primary air to help burn off the creosote. Plus letting the wood firebed burn top down to bottom, it will last longer.

With coal, the majority of the air must feed up through the grates from the primary damper (that's why it's called the primary). You use the secondary to burn off the large amounts of volatile gases that a fresh batch of coal produces.

Then when the firebed is burning well, and the blue ladies appear, you can close the secondary down almost all the way. You should see the blue ladies even better then. I know that with my two stoves the blue ladies don't like cold, they don't come out to dance if it's drafty over the fire.

Some guys have good results opening the secondary to help slow the fire to get longer burn times or les heat output during warm spells. But that seems to only work on stoves with bigger firebeds, and/or, if you have a strong enough drafting chimney system, as in your case.

If the chimney draft is weaker, too much secondary air will just make it weaker still. That can eventually lead to the draft strength getting so low that the fire stalls and goes out.

Paul

Thank you very much for the explanation. 12 and a half hours later and its still burning good. I'm going to shake and load it and leave the settings where they are for today.

Here's an update on the stove. Its been burning for a week now no problems. The house is nice and toasty. I've been running it on a 12 hour schedule, shaking and loading at 6 am and again at 6pm. I'm burning 30 to 40lbs a day, keeping it shut down as low as I can. Everything is working just as I hoped. Thank you all for your help and input!

Good news. Glad to hear the learning curve has straightened out a lot, for ya.

Paul