mansfield high temp?

[bebopin]

Just wondering what is the highest temp you have got yours to. Also what is the best way you have found to char your wood? with front door open or with the ash pan door open?
We have had ours up to 600-625. getting good secondary burn and starting to love it.

 

[struggle]

The manual says not to go over 600 as it is overfire :ahhh:

I have had mine at around the 625 range and it gets way tohot in the basement in that range.

I get secondary burn at temps below 300 but the fire is intense at that time building heat.

If you have to char the wood buy leaving the door or ash pan open I am suggesting using smaller splits to get the intial fire going and then lay on the bigger peices.

You should never have to leave the ash pan or door open to get a good fire going. Are you having draft problems or lack of draft?

 

[bebopin]

No, the draft is good.Have not checked it but when I look at the top of the stack i can see the heat radiating.also my wood is not the driest.but i am working on getting some better wood this week.I was just wondering what others are doing with this stove.This is a good source for my learning curve.

 

[Highbeam]

I have the heritage which is very similar to the mansfield and I do not need to leave anything cracked or open to char. Plenty of air comes in with the draft control wide open. My stove has been 550 and almost 575 but never 600 since it might turn to dust since that is the overfire rating.

I get secondary combustion with a cool stove like Struggle. I get really good secondary action with a closed draft control above 400.

 

[swestall]

I have a question in to Hearthstone about this exact issue. I've seen 637, not that I wanted to but in these past few days that have been at 10 degrees or less I have had a problem twice. I would get the load carred and then shut down the damper all the way. At that point the secondary burn tubes would take off like a jackrabbit and the heat would keep rising. This was not a good experience but I was able to control it: Mansfield owners take note: there are two small oval holes in the rear bottom of the stove that suck air into the secondary manifold. I plugged these up with the curled over thumbs of my leather gloves and the fire abated. Now, the manual says that you can/should install a pipe damper in the flue pipe if your draft is too strong. I didn't do that because before we had the low temps it was not an issue. I also noticed that this happened when I was burning north/south: it didn't seem to happen on an East/West burn. I've changed my overnight and daytime burns to E/W and use the N/S to get fast heat when I get home and in the morning.
But, it leaves me wondering what they actually run these things up to in the lab and why they say 600 is the top. At 600 it seems to be putting out the amount of heat I would expect an 80K/BTU stove to generate. I'd love to burn this thing at 550-600 all the time. So, what I am asking them to tell me is what is the margin of safety in the 600 degree limit, if any. I know it will take 637 without a problem; excepting that you get scared and have to change your shorts when you see it!
Will post a separate thread or to this one if I can get an answer from them; if no satisfaction then I'll try going through the dealer service dept. as they are pretty good here. In fact, I'll also PM Tom Oyen to see if he can help with this question as well.
Best to all.

 

[struggle]

I know what you are talikng about as my stove will go crazy secondary burn and the stove top will rise very fast in what you experienced. I have even had this happen with a dampner in place. My draft is very strong and gets amplfied on the really cold nights.

To cool the stove off I run a tower fan about 5' from the stove sweaping across the stove and it keeps the stove right around 500 then.

AS far as damage I am unsure of what will happen beyond cracking stones which I believe is the main concern and I am guessing that if you experience sudden heat temp changes from low to high that is what really causes the problems with going to the higher temps and cracking stones. I find it hard to believe the casting parts would suffer damage from 600 degrees.

Something else to prevent the high fast secondary burn rate like this is to rake all the coals to the front of the stove and let the wood burn back loading E/W and this seems to slow the stove down compared to loading a bunch of splits on hot coals all the way accross.

 

[thechimneysweep]

I think there's a tendency to be overly concerned about overfiring. With thousands of woodstoves sold, I can only remember a couple of cases where overfiring resulted in irreparable damage to the stove, and both were WAY outlandish situations. Even in those extreme cases, it took several seasons for the damage to evidence itself. And in both cases, the manufacturer honored the warranty anyway.

In normal operation, woodstoves are impossible to keep at a constant temperature. It is simply the nature of a wood fire to peak and trough, and the swing can be several hundred degrees. Manufacturers know that, and build their stoves to take the hit.

I spoke to Hearthstone today, and learned that they have tested their stoves to an outside surface temperature of 700 degrees, the point at which they become concerned the stones might crack. This doesn't mean that all the stones cracked at temperatures above 700 degrees, just that at least one did. Anyway, having established a red zone at 700 degrees, they play it safe with their posted 600 degree limit, realizing that this limit might include spikes approaching 700 degrees at times.

Note: it is really, really hard to get the surface of a soapstone stove up to 700 degrees. It will probably never happen in your lifetime.

 

[Todd]

INote: it is really, really hard to get the surface of a soapstone stove up to 700 degrees. It will probably never happen in your lifetime.

Tom,
Woodstock states overfire at 700. I have seen 735 a couple times and currently had it at 680 til I brought the air back. I can easily get up to 700 if I want to. Maybe it's because the cat is right under the top stones? Do you think the difference in overfire temps is due to the cat, different stone, or they are just using the 700 number with no fudge in it?

 

[struggle]

Note: it is really, really hard to get the surface of a soapstone stove up to 700 degrees. It will probably never happen in your lifetime.

Sounds like a challenge to me. Let the soapstone stove heat races begin :coolgrin:

 

[thechimneysweep]

I don't know why the temperature difference. Woodstock uses two layers of stone with an airspace in between, so you'd think their surface temp would be cooler, if anything. The two companies get their stone from different places, so it might be the character of the specific stone.

There's a soapstone quarry a few miles from here in Marblemount, WA, and when we were kids we used to drive up there and load up "reject chunks" that had been tossed over the bank by the people working the quarry. They called this "artist quality" soapstone, and it was way more colorful than the stuff used in stoves. The color came from veins of minerals running through the soapstone, and could range from brown to deep orange and various shades of green and blue.

Soapstone is soft, and can be cut with a pocketknife. We used to carve pipes out of our harvested reject chunks, for smoking a certain rare herb used in religious ceremonies and for treatment of the side effects from certain medical procedures. Under strenuous use, the more colorful pipes had a marked tendency to crack along the lines of color separation. We always attributed this to the different rates of thermal expansion in the various materials that ran through the stone. At any rate, the pipes carved from basic gray soapstone definitely held up better. Still have one somewhere.

So, I suppose it is possible that other materials running through the soapstone from a given quarry, or lack of same, could affect the maximum temperature a stove could achieve, or the temperature at which it might crack.

Might just dig up that pipe and do a little research.

 

[swestall]

Thanks for the help on this one Tom; always a pleasure to get your input.
Steve.

 

[Todd]

Soapstone pipes, that's funny. There is a difference in the soapstone colors of Woodstock and Hearthstone. Woodstock is a light gray/blue with some white in there, mined in Canada. Hearthstone is darker gray with different swirley colors and mined in Brazil.

 

[Reggie Dunlap]

I've had my Mansfield at 700 lots of times, and probably hotter than that for short periods. I don't know if it has hit 800, but I wouldn't be surprised. When it's really cold here I let it run between 5-600 and don't worry too much if it gets up toward 700. It throws some serious heat at those temps and that's a good thing when it's 20 below. I have a stainless liner up through a huge masonry chimney so high stack temps don't worry me much, and I've never had any creosote.

I replaced the steel baffle this fall because it was crumbling. I don't know if it fell apart due to high temps or because the stove has burned 4-5 cords a year for 9 years. Either way the baffle replacement is an easy job.

 

[bebopin]

Looks like I asked a good ?. I will add more later as I have to be off to work. Phil

 

[bebopin]

Well I have been burning for 2 weeks and all is good.Stove is putting out good heat (wife said it is hot in hear :gulp: ). I never thaought I would hear that from her.
I put in a internal pipe thermometer and when the stove top temp is 450-550 the pipe temp is about 200 all the time. I did let the fire get burning good and hot and the temp got to 800 for awhile.But when I closed the air down to half and started the secondary burn it was back down to 200.also I have a damper and if it is 1/2 closed the stove temp rises and the pipe temp holds at 200.

Well that is all for now hope everyone is staying warm. Phil

 

[Todd]

200 internal pipe temp? That is awfully low for a stove crusin at 450-550.

 

[jpl1nh]

INote: it is really, really hard to get the surface of a soapstone stove up to 700 degrees. It will probably never happen in your lifetime.

Tom,
Woodstock states overfire at 700. I have seen 735 a couple times and currently had it at 680 til I brought the air back. I can easily get up to 700 if I want to. Maybe it's because the cat is right under the top stones? Do you think the difference in overfire temps is due to the cat, different stone, or they are just using the 700 number with no fudge in it?

I've been up to and just over 700 several times too, like you say, that's measured directly above the cat which when really cranking is probably hitting 1400+. I bought my stove with about 4 years use on it and the by-pass door and by pass door housing were warped. I don't think the previous owners used the cat, there was so much ash packed in it and between the cat and the protective metal screen that no air could possibly get through it. They had a straight pipe up through the ceiling and told me they regulated the fire with the pipe damper only.. :ahhh: Can't imagine what temps they had screaming through the by-pass. The stone is fine though, no blemishes anywhere. At least the cat still has lots of life to it, seems it was hardly ever used. :coolsmirk:

 

[bebopin]

That is what I thought also.The wood is not wet. Have had it split and in the house near the stove and mixing it with wood from store that is dry. I am just not sure if I am burning this stove the right way.Good heat output does not mean the best burn. I did buy some wood today that is well seasoned and it is also smaller piece's. We will have to see if that makes a deference in the way the stove acts