overfire in Castine?

[dvellone]

My Castine took off tonight with a load of very dry hard maple and the surface thermometer was registering 700 with secondaries roaring away. I'd shut the air down all the way which I usually can never do and it still roared on, and I then saw the red glow of the air deflector(?) inside at the top of the door. I blocked off the rear air intake and got things slowed down- temp started slowly falling with secondaries burning nicely but not roaring. Though it's high I didn't think that 700 was necessarily an overfire, but the red air deflector is the give away... right?

I've got a lot of this dry hard maple ahead of me this season. Maybe install a damper.

 

[BrowningBAR]

My Castine took off tonight with a load of very dry hard maple and the surface thermometer was registering 700 with secondaries roaring away. I'd shut the air down all the way which I usually can never do and it still roared on, and I then saw the red glow of the air deflector(?) inside at the top of the door. I blocked off the rear air intake and got things slowed down- temp started slowly falling with secondaries burning nicely but not roaring. Though it's high I didn't think that 700 was necessarily an overfire, but the red air deflector is the give away... right?

I've got a lot of this dry hard maple ahead of me this season. Maybe install a damper.

I have a Damper installed on the Vigilant and Heritage. But, if you only hit 700, I think you should be fine.

 

[adrpga498]

I usauly cut down air to 1/2 whe nit hits 550-600. Then she might spike up to 700-750. Won't stay there more then 20 minutes and will settle out about 600-650. Thats the cruising speed I like. I don't have outside or secounday air kit but I can't say I've ever seen the red glow on the defletor up top and front. So in a word I'd say your FINE. Cheers

 

[Backwoods Savage]

700 is not a temperature that most folks would worry about as far as overfiring, but exceed that and it can get touchy.

 

[JotulOwner]

That happened to me as well. The secondaries were blowing like a blast furnace and the deflector did glow a deep red color for a short while (seemed like forever). I haven't noticed any problems resulting from that. I think I may have added too much wood to an already hot stove. It seems like loading north-south increases the effect. Now, if I add any wood, I pay close attention to the temperatures before deciding what to add.

 

[begreen]

700 is far from overfire in a Castine. I had mine over 800°F a couple times with no ill effect other than some personal cleanup needed on my behind. :red:

 

[jerseykat1]

not the same stove but my napoleon economizer sees 700-800 on a daily basis, i try not to hit 800 but sometimes its unavoidable. Stoves are made of steel not aluminum and steel has a very high melting point, i would not worry about 700-800 degrees, and a little bit of warping would likely be the only ill effect on a device that is not exactly a precision instrument (meaning it can warp a bit and still function 100%), as long as your flue is not cheap, flimsy and you dont have a bunch of flammables by your stove you will be just fine. Fire that sucker up

Manufactures tell you not to exceed xyz temperature because they have to warranty it if you screw it up and there is no telling if you had it installed safely (protect there ass), but they are also built to take a LOT of heat.

 

[begreen]

Cast iron can take a lot of heat too. If you've seen cast iron car manifolds glowing in daylight, you know what I mean. It's tough stuff. The greater concern would be if it is enameled. I'm not sure at what temp the enameling is destroyed. We've had our 602 over 900F without issue. But the back enamel bubbled when a house sitter overfired the stove. Must have been cherry red.

 

[dvellone]

Thanks for all the replies. I'm fanatic about the stove temperature and always on top of closing the air down long before things get out of control. Last night with a cold overnight forecast I loaded up with hard maple and my splits are fairly small because I generally run smaller fires to keep from overheating my space. So, I think the combination of very dry maple, multiple small splits with plenty of space between, and letting the fire build to a 550 roar before shutting things down were what contributed to the spike. My concern was that I couldn't slow it down by shutting the air control completely down which otherwise will normally stall the fire. Instead it roared on with the red glow making me feel like things were completely out of control in there. I remembered a poster here commenting that he kept a balled up piece of aluminum foil handy for this very situation so that's what I did and it got the fire instantly under control! Anyhow, the last thing I want to do is compromise my investment by overfiring.

 

[begreen]

No problem, based on the description it wasn't close to overfiring. For the overnight temps you folks are seeing I'd be running that stove at 650+°F. When we had a week long power outage our Castine saw those temps pretty regularly.

 

[dvellone]

No problem, based on the description it wasn't close to overfiring. For the overnight temps you folks are seeing I'd be running that stove at 650+°F. When we had a week long power outage our Castine saw those temps pretty regularly.

That's what I understood, that 700 wasn't a problem. But the glowing air deflector is what really makes me apprehensive to approach that temp again. My thermometers aren't state-of-art accurate - just rutland spring models, and I wouldn't be surprised if they were off a bit though the two I keep were dead on 700 at peak.
Should I see a red glow on the deflector at a 700* surface temperature or should I assume that the thermometers are off and registering 700 while the interior is beginning to glow indicating a higher temperature? The deflector is at a point where it's receiving the brunt of the secondary heat.

As far as the cold tonight, this is where my choice of the castine in our 800 square' cabin pays off! Load and go to bed without a whiff of deep cold stress.

 

[OhioBurner©]

That's what I understood, that 700 wasn't a problem. But the glowing air deflector is what really makes me apprehensive to approach that temp again. My thermometers aren't state-of-art accurate - just rutland spring models, and I wouldn't be surprised if they were off a bit though the two I keep were dead on 700 at peak.
Should I see a red glow on the deflector at a 700* surface temperature or should I assume that the thermometers are off and registering 700 while the interior is beginning to glow indicating a higher temperature? The deflector is at a point where it's receiving the brunt of the secondary heat.

As far as the cold tonight, this is where my choice of the castine in our 800 square' cabin pays off! Load and go to bed without a whiff of deep cold stress.

I'd bet that rutland is off. 700 is nothing for my Jotul 550 - I got the baffle glowing a couple weeks ago and the stovetop was a bit over 900ºF (accident - and I dont have the ability to block the secondary air like you do). Even at that temp though it was only glowing right on the edge.

I have a rutland on my old stove, the old stove runs a bit cooler, usually around the 400-500 mark and the rutland reads about 75º low, much over 500 and its probably about 100º off. No idea how far off it would be at 700-900. The other problem is it only gives you temp at one point. I'm sure you have your stove figured out to where it gets the hottest, but nice thing about having an IR gun around you can quickly sweep over the whole surface and see what the temps are everywhere, plus you can use it to 'calibrate' your other thermomenters, assuming its calibrated well (even without verifying its cal I'd still trust it over the rutland any day). Sometimes, depending how you load it, if you had the door cracked open for a while, etc, it may be hotter in different areas.

 

[Wade A.]

Put me in the column for "not a big deal." Taking into account the +/_ variable for the thermometer, I've had that hot a fire in my Castine on several occasions, with no damage. Now, I wouldn't go there on purpose, but you'll get away with that every now and then. Don't leave it there for long is the key, and you didn't. You've learned that loading sub 10% m.c. hardwood to the gunwales, on top of a good coal bed, will get your temps up pretty damn quick in that stove. 'Nough said.

 

[begreen]

Was this a particularly tall load in the stove, up near the manifold? It sounds like the flame was impinging directly on the air deflector. It has to make a 180° turn at that point and is like a blowtorch on the deflector. I could see it getting quite hot. Seems to me that as long as the stove top is staying well under 900, it's probably ok. Ours glowed a very dull red a couple times and the top was around 700F. If it was glowing bright cherry red I would be a bit more concerned.

 

[DawgDoc]

The same thing happened to me last week. I didn't know where the rear air port was and used 2 fans to cool the stove down. It worked!

 

[kobudo]

Where is the rear intake?
If you have a photo please post it.
I think I will start keeping a ball of foil handy.

 

[begreen]

Bottom, rear center of the stove.

 

[gpcollen1]

No problem, based on the description it wasn't close to overfiring. For the overnight temps you folks are seeing I'd be running that stove at 650+°F. When we had a week long power outage our Castine saw those temps pretty regularly.

That's what I understood, that 700 wasn't a problem. But the glowing air deflector is what really makes me apprehensive to approach that temp again. My thermometers aren't state-of-art accurate - just rutland spring models, and I wouldn't be surprised if they were off a bit though the two I keep were dead on 700 at peak.
Should I see a red glow on the deflector at a 700* surface temperature or should I assume that the thermometers are off and registering 700 while the interior is beginning to glow indicating a higher temperature? The deflector is at a point where it's receiving the brunt of the secondary heat.

As far as the cold tonight, this is where my choice of the castine in our 800 square' cabin pays off! Load and go to bed without a whiff of deep cold stress.

While I don't try and make the secondary baffle glow, it can happen. not a big deal as that will not warp the stove or anything. My secondary tubes on the olympic get a good glow here and there. That stove can take the heat boy...

 

[firefighterjake]

Put me in the "concerned, but not too worried about long or short term effect" column . . . I would have been monitoring temps and may have stepped in to help things . . . but would not worry about overfiring at those temps . . .

That said . . . I might be a little more careful in the future . . . shut 'er down earlier, watch the size of the splits, load size, etc.

 

[JotulOwner]

No problem, based on the description it wasn't close to overfiring. For the overnight temps you folks are seeing I'd be running that stove at 650+°F. When we had a week long power outage our Castine saw those temps pretty regularly.

That's what I understood, that 700 wasn't a problem. But the glowing air deflector is what really makes me apprehensive to approach that temp again. My thermometers aren't state-of-art accurate - just rutland spring models, and I wouldn't be surprised if they were off a bit though the two I keep were dead on 700 at peak.
Should I see a red glow on the deflector at a 700* surface temperature or should I assume that the thermometers are off and registering 700 while the interior is beginning to glow indicating a higher temperature? The deflector is at a point where it's receiving the brunt of the secondary heat.

As far as the cold tonight, this is where my choice of the castine in our 800 square' cabin pays off! Load and go to bed without a whiff of deep cold stress.

I have two Rutland stove top thermometers (one on each side of the stove top), a Condar Fluegard stove pipe thermometer and an IR gun (I like redundancy when it comes to safety devices - especially CO detectors). I thought the Rutlands might be inaccurate, but, it turns out that the temps on different parts of the stove top vary greatly. I find them to be pretty accurate when compared to the IR readings.

 

[dvellone]

Was this a particularly tall load in the stove, up near the manifold? It sounds like the flame was impinging directly on the air deflector. It has to make a 180° turn at that point and is like a blowtorch on the deflector. I could see it getting quite hot. Seems to me that as long as the stove top is staying well under 900, it's probably ok. Ours glowed a very dull red a couple times and the top was around 700F. If it was glowing bright cherry red I would be a bit more concerned.

Yes, exactly. Not only a tall load but, as I mentioned earlier, smaller splits with plenty of airflow between.

I'm greatly appreciative of all the input here. My family ruined a stove at our camp from much overfiring and so I'm a little more than a bit nervous about it.
Time for a more accurate thermometer.

 

[prescottonian]

Hi good people,
As for over-firing at 700 degrees , I highly doubt anything happens . The melting point for high carbon steel is 2500 degrees . I assume that all steel stoves are heat treated after they are welded , so the welds relax .
700 degrees could possible warp or anneal the stove to some degree but I have my doubts . In my humble opinion unless you dump cold water on it at the temp , your good . I tried to melt a 55 gallon drum I made into a stove by cutting a hole in it and putting legs on it with a stove pipe on top. I could not do it . I got that sucker glowing red but it didn't melt . The heat transfers to fast .

 

[Wade A.]

Prescottonian....all true, no doubt, but the issue with a cast stove like the Castine is the cemented seams coming un-seamed, and plates possibly cracking. There are no welds, to my knowledge, just gaskets and furnace cemented joints, with bolts. Melting is probably not ever going to be a possibility, as you noted. At the least, you might wind up with a messy and expensive rebuild if you don't watch your temps. But I think the consensus here is that this incident was not anything to be overly concerned about.

 

[prescottonian]

My bad ,
I did not realize it was a cast iron stove .