cast iron wood stove modification

[jamesdeano123]

I have a couple of old cast iron stoves. Instead of getting rid of one of them I was just wondering what would happen if I took some of the parts from one stove (like the top, back or a side) and tack welded it to the other stove. I'm not talking about modifying a door, intake or vent Would the extra mass help hold more heat or lose it because of too much thickness?. Some of the pieces have beautiful designs in them which I would hate to loose.

 

[St. Coemgen]

Personally, I would simply place them on a shelf and display them as works of art.

If you want to add them to a stove, do so in a way that the current metal of the current stove, and these panels, can move independently with expansion and contraction so they can respond to heating and cooling in their own way, and not directly tied to each other. Old iron may expand/contract differently under heat from new iron or steel. So, I would not weld them together. And any welding may leave a mark, decreasing their historical value.

 

[Jags]

First question would be....have you ever tried to weld cast iron? It can be done, but is darn near an “art”. There is a reason that cast iron stoves are assembled, not welded (like plate steel). Second, I doubt that you will notice any meaningful gain because of the added mass. Remember, its BTU’s in and BTU’s out with “efficiency” Being the wild card. Extra mass will hold heat a little longer, but it also takes longer to heat up in the first place.

 

[peakbagger]

They are nice castings. The problem with adding mass is it has to heat up. Its pay me now pay me later deal. You dont get heat as quick when you light off as the cold cast iron has to heat up. Stoves are mostly radiant heat and putting anything between the hot stove and the cold body in the room reduces the radiant heat felt by the cold body. I agree with prior poster. Hang it up as art.

 

[jamesdeano123]

Thank you for your comments, they are just as I expected. And yes , welding cast is a groan, plus I probably would have cracked the stove I would have welded to, and I'm sure if a thicker 2 layer cast stove heated better, they would make one. I was just trying to think of something new. I guess it would have had the same effect as the time I surrounded the stove with soap stone . Just like you guys said, holds the heat but takes forever to heat up. I finally looked it up, and If I were one of the people who understood

then I think I could make a better stove. Oh well!

 

[mikey]

Thank you for your comments, they are just as I expected. And yes , welding cast is a groan, plus I probably would have cracked the stove I would have welded to, and I'm sure if a thicker 2 layer cast stove heated better, they would make one. I was just trying to think of something new. I guess it would have had the same effect as the time I surrounded the stove with soap stone . Just like you guys said, holds the heat but takes forever to heat up. I finally looked it up, and If I were one of the people who understood

then I think I could make a better stove. Oh well!

If you also have a open fireplace those panels will make great firebacks.

 

[Isaac Carlson]

Every material conducts/insulates to a certain degree. Thicker steel/iron insulates better than thinner metal. Adding these to the outside of a stove will put more heat up the stack.

I grew up with barrel stoves. We had one in the shed and one in the house. They put out a tremendous amount of heat because of the thin metal. The heat just goes right through it. It was not difficult to reach over 100* in the house.

 

[bholler]

Every material conducts/insulates to a certain degree. Thicker steel/iron insulates better than thinner metal. Adding these to the outside of a stove will put more heat up the stack.

I grew up with barrel stoves. We had one in the shed and one in the house. They put out a tremendous amount of heat because of the thin metal. The heat just goes right through it. It was not difficult to reach over 100* in the house.

That has much more to do with the size of the firebox than the thickness of the metal

 

[bigealta]

Can u make a stand for them to hang from and place them on the sides or behind the stove as "heat shields".

 

[Isaac Carlson]

Heat tranfers through thinner metal much faster than it does through thicker metal. Adding another plate to the outside of the stove will reduce the heat flow through the assembly. It's like putting another layer of siding on your house. The insulation value goes up. In the case of steel, it is a poor insulator, but having 5-10x more thickness ( plus any air space or gaps) makes a difference. Thin steel heats up quickly with less energy input, while thicker steel tends to soak up heat and hold onto it.

I can stand pretty close to my 1/4" thick cook stove with a roaring fire, but I would have to be at least 4 feet from a barrel stove with the same fire in it to keep from getting burned. The reason wood stoves are not made from sheet metal any more is because it does not last as long as 1/4" plate and it is easier to warp/sag/melt and it doesn't hold heat or even out the temp cycles.

Make a stove out of 1/4" plate and make an identical stove with sheet metal. The sheet metal stove with throw more heat than the thicker one with the same fire. Heat exchangers are thin for a reason. You could make an oil cooler with 1/4" steel, but it wouldn't do much.

Material thickness directly affects conductive heat transfer. Double the thickness and the conductive heat transfer is cut in half.

Steel is a pretty good insulator when compared to other metals, bit it will take quite a bit of heat and is relatively easy to work with, tough, and cheap.

 

[bholler]

Heat tranfers through thinner metal much faster than it does through thicker metal. Adding another plate to the outside of the stove will reduce the heat flow through the assembly. It's like putting another layer of siding on your house. The insulation value goes up. In the case of steel, it is a poor insulator, but having 5-10x more thickness ( plus any air space or gaps) makes a difference. Thin steel heats up quickly with less energy input, while thicker steel tends to soak up heat and hold onto it.

I can stand pretty close to my 1/4" thick cook stove with a roaring fire, but I would have to be at least 4 feet from a barrel stove with the same fire in it to keep from getting burned. The reason wood stoves are not made from sheet metal any more is because it does not last as long as 1/4" plate and it is easier to warp/sag/melt and it doesn't hold heat or even out the temp cycles.

Make a stove out of 1/4" plate and make an identical stove with sheet metal. The sheet metal stove with throw more heat than the thicker one with the same fire. Heat exchangers are thin for a reason. You could make an oil cooler with 1/4" steel, but it wouldn't do much.

Material thickness directly affects conductive heat transfer. Double the thickness and the conductive heat transfer is cut in half.

Steel is a pretty good insulator when compared to other metals, bit it will take quite a bit of heat and is relatively easy to work with, tough, and cheap.

Steel has an r value of . 003 per inch. The difference in resistance between sheet and plate is not enough to make any difference. The difference comes from the firebrick and heat shields. As well as the generally uncontrollable nature of most barrel stoves.

Now adding another plate will make a huge difference because it will act as a radiant heat shield. But that is due to the air space.

 

[begreen]

Before cannibalizing the stove(s), determine the value.

 

[stoveliker]

Any comparison between a stove with one layer and more layers is due to the airgap convective heat release and/or the impedance to heat flow due to the interface between the layers if they are snug.

 

[EatenByLimestone]

there are times you want a lot of heat out of your fuel load, and times you could justify, if not want some of that heat to be stored a little while. Shoulders are the first time that jumps out in my head. Tops of stoves are generally flat. You could lay the old piece on top.

However. I wouldn’t expect much from it. You’re adding 20-40lbs probably. I don’t think that will change much.