Concerned about stove top temp differential and metal integrity, please help.

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Dave K

Burning Hunk
Sep 26, 2013
122
Sussex County, NJ
I took a bunch readings with my IR thermometer last night (all pics were taken within 2 minutes) and noticed that the stove gets a lot hotter on certain parts of the stove top than other spots (closer to the stack is almost 100 degrees different). Is this normal? Here are some pictures of the stove, you can tell that certain areas are a little discolored and that makes me question the integrity of the metal. The fire was roaring at the time of these pics. I know the stove has been used consistently for many winters and it may be fine to operate like this. Am I just being paranoid, or should I be concerned?

[Hearth.com] Concerned about stove top temp differential and metal integrity, please help.

Here is the top right and top left as well as the top-middle. Notice that as you get closer to the stack it is significantly hotter than the outside edges

[Hearth.com] Concerned about stove top temp differential and metal integrity, please help. [Hearth.com] Concerned about stove top temp differential and metal integrity, please help.
[Hearth.com] Concerned about stove top temp differential and metal integrity, please help.
[Hearth.com] Concerned about stove top temp differential and metal integrity, please help. [Hearth.com] Concerned about stove top temp differential and metal integrity, please help.

I feel that the temp differential shouldn't be this far apart. Has the metal weakened? should I worry about this?

Here is the temp difference on the bottom step...

[Hearth.com] Concerned about stove top temp differential and metal integrity, please help. [Hearth.com] Concerned about stove top temp differential and metal integrity, please help. [Hearth.com] Concerned about stove top temp differential and metal integrity, please help.

Lastly, here is the back of the stove. You can see that some of the metal has a whitish tint.

[Hearth.com] Concerned about stove top temp differential and metal integrity, please help.


Thanks for your input and for reading this. I thought you guys would have some opinions on this and this is the place to learn!!
 
Those temps aren't anything to worry about. If you want to check the integrity of the metal, wait until it cools down and then inspect it by hand. Look for rust. If you find some, try to scrape it off with a screwdriver. If your screwdriver pokes through the metal, worry about it. If not, don't worry about it.
 
Those temps aren't anything to worry about. If you want to check the integrity of the metal, wait until it cools down and then inspect it by hand. Look for rust. If you find some, try to scrape it off with a screwdriver. If your screwdriver pokes through the metal, worry about it. If not, don't worry about it.


I've gotten those temps a lot hotter than shown in the picture. I usually keep the top at about 450-600. I just wanted to show the difference in the temps and ask if that is a potential problem. The fact that the metal looks a little "white-ish" is the reason that I am concerned. I let the stove burn while I'm at work so I want to make sure that there isn't a problem
 
Happens with ever stove I have ever owned. I find hundred degree differences in readings six inches from each other on the top plate. In fact one of the things people liked about the step top on that old stove is that you had different temps on the upper and lower steps for cooking different stuff at the same time.

Perfectly normal. Except for the part about white spots. Quit burning the crap out of it. >>
 
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Happens with ever stove I have ever owned. I find hundred degree differences in readings six inches from each other on the top plate. In fact one of the things people liked about the step top on that old stove is that you had different temps on the upper and lower steps for cooking different stuff at the same time.

Perfectly normal. Except for the part about white spots. Quit burning the crap out of it. >>


haha, thanks BB! I just bought the house, so I wasn't the one burning the crap out of it.

Near the base of the stack (in front) and at the back of the stove is a little white (as seen in those pics I posted) and there are some rust spots. It kind of looks a little pitted. Is this normal also?
 
I'd only worry if the metal is really thin. They making stoves with 3/16ths inch thick steel.

(broken link removed to http://www.century-heating.com/en/products/wood/wood-stove-on-pedestal-model-fw2700)

That tells me that steel 1/8" thick is probably adequate. If you get down to 1/16th, or .0625", you can probably put a screwdriver through it if you jab it hard enough. Even then, if the thin spot is small enough, you can get a welder to add more metal or weld a plate over it.
 
I'd only worry if the metal is really thin. They making stoves with 3/16ths inch thick steel.

(broken link removed to http://www.century-heating.com/en/products/wood/wood-stove-on-pedestal-model-fw2700)

That tells me that steel 1/8" thick is probably adequate. If you get down to 1/16th, or .0625", you can probably put a screwdriver through it if you jab it hard enough. Even then, if the thin spot is small enough, you can get a welder to add more metal or weld a plate over it.

Its an old Fisher stove, and according to Coaly's Fisher thread... "ALL Fisher stoves are welded 1/4" thick steel plate, most having 5/16" thick tops. ALL steel plate construction is specified to be HRS or Hot Rolled Steel. Shield material is 22 gauge cold rolled steel."

So I should be fine, right?
 
The white metal is a sign of overfiring but with 1/4" thick steel I wouldn't worry too much unless I saw some warpage, cracks or popped welds. Clean it out real good and inspect it inside and out.
 
Yep.
 
The white metal is a sign of overfiring but with 1/4" thick steel I wouldn't worry too much unless I saw some warpage, cracks or popped welds. Clean it out real good and inspect it inside and out.

Okay thanks.

I have checked the whole stove and haven't found any popped welds or cracks. See this pic... at the rear of the stove where it is a little white, the metal bulges out a little bit. I don't know if you can tell from the pic but there is a little bulge. This is right above the firebrick. Is this considered warping? If so, what should I do?

[Hearth.com] Concerned about stove top temp differential and metal integrity, please help.
 
5/16 thick top not to worry.
Probably not Satin Black Stove Bright paint. hint hint it's ready.
Smoke Shelf Baffle time. ;) Discoloration shows where the heat is. Up the stack !

I bulge out a little too, but work just fine.

Here's hot, no damage done; 1/4" stove body, 5/16 top same as yours.

[Hearth.com] Concerned about stove top temp differential and metal integrity, please help. [Hearth.com] Concerned about stove top temp differential and metal integrity, please help.
 
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5/16 thick top not to worry.
Probably not Satin Black Stove Bright paint. hint hint it's ready.
Smoke Shelf Baffle time. ;) Discoloration shows where the heat is. Up the stack !

I bulge out a little too, but work just fine.

Here's hot, no damage done; 1/4" stove body, 5/16 top same as yours.

View attachment 119574 View attachment 119575


Wow, okay that makes me feel better because its not nearly as white as yours! I am working on getting a steel plate cut for my baffle. Plan on having that installed by Xmas.
 
And maybe a ... d a m p e r ??
 
And maybe a d a m p e r ??


Haha yes. I plan on taking all of your suggestions and implementing them. I just have to find the time!!! Between working 10hr days and then getting home to stack wood, unpack boxes, etc I can't seem to find much time recently!!
 
Our stove top is not steel, but we see 100F differances all the time from corner stone to center stone.
 
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Some of these Steel stoves will glow a bit in normal high operation won't they, around the flue? Jay

Only if it is over fired.

(broken image removed)
 
Notice the paint color on this Papa Bear and how much heat was going up the pipe !
This was burning all soft wood, pines and fir.

[Hearth.com] Concerned about stove top temp differential and metal integrity, please help.

Also notice there IS a damper in the pipe of this installation.
The manuals for (single door) Bear Series stoves did not suggest a damper.
They were required on (double door) Fireplace Series only.

Always wondered about why they were not required on all models, and I've always recommended them.
Here's proof from the stove king's home himself !
 
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Notice the paint color on this Papa Bear and how much heat was going up the pipe !
This was burning all soft wood, pines and fir.

View attachment 119605

Also notice there IS a damper in the pipe of this installation.
The manuals for (single door) Bear Series stoves did not suggest a damper.
They were required on (double door) Fireplace Series only.

Always wondered about why they were not required on all models, and I've always recommended them.
Here's proof from the stove king's home himself !

Now that seems like a hot pipe!! I wonder why my Grandma Bear (Its a 1979 I believe) didn't have a baffle or a damper if they were required on the fireplace series. Possibly the maker of mine didn't follow the plans completely?
 
I wonder at what temps do you have to burn at to turn the metal white like that?
 
It's just the paint oldspark. Some high temp paints are more resistant to it.

The Smoke Shelf Baffle was added when the models became the redesigned Model III in 1980 and after. It was one of the attempts to reduce smoke.

The instructions include a damper required for double door stoves for open door burning. That is the only control you have with screen in place with doors open. Slowly close damper until smoke starts to roll in at top, and open slightly to slow draft but allow no smoke inside. They were not considered a radiant heater with doors open in fireplace mode.
 
It's just the paint oldspark. Some high temp paints are more resistant to it.

The Smoke Shelf Baffle was added when the models became the redesigned Model III in 1980 and after. It was one of the attempts to reduce smoke.

The instructions include a damper required for double door stoves for open door burning. That is the only control you have with screen in place with doors open. Slowly close damper until smoke starts to roll in at top, and open slightly to slow draft but allow no smoke inside. They were not considered a radiant heater with doors open in fireplace mode.

Gotcha! I don't use the stove with doors open, unless I'm starting it cold.
Thanks for clarifying that it is the paint that gets discolored. I too thought it was the metal
 
Yes, open door burning with a screen is a novelty that usually wears off after a few fires. I found their best use was quickly starting a fire or in the case of damp or wet wood that would smolder and die with less air than wide open.
 
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