Beefing up a Castine...

[Wade A.]

So....I have a nice slab of 6/4" limestone left over from my hearth installation. (Let me give you some free advice...don't ever try to move a 200 lb. slab of that on your own. Because, well...just trust me on that) I've been thinking that I could top my F400 with a slab of that and get a huge jump in my thermal mass. Then again, maybe all I'd do is melt the top plate. What do you think?

 

[jotulguy]

I wish I could find the thread that was done on this already. Let me try and sum it up for it you. It didnt work.... in fact the stove heated less. The reason is the block on top of the stove slows down the heat coming off the stove. It for sure did not improve the output and wont on any stove.

 

[firefighterjake]

Nice idea in theory . . . but not enough mass. I did something similar with a slab of soapstone that I put on my Oslo . . . it look nice in my opinion, but a single slab of stone on top of a stone does not magically convert a cast iron or steel woodstove into a stove having the same properties of a soapstone stove. I wouldn't say it has hurt the heat output or thermal retention of the cast iron stove . . . but it hasn't really helped things either.

If you do a search on this site you can probably find my original thread with pics and a description of what I did . . . I used some spacers for example to make sure that I didn't overheat the stove by just laying a slab of stone on top.

 

[pen]

The stone works well in a soap stone stove because the flames are actually licking the backs of the stones. Placed on top of a metal, you won't get the same heat transfer and will actually slow the removal of heat from your stove and give it a better chance to go up the chimney.

pen

 

[Wade A.]

Figured it had been tried before.....and I'm glad to have the collective wisdom of this forum to spare me from recreating a (broken) wheel. One thing that did cross my mind is that the top of the stove is going to take whole lot longer to heat up initially, and that would probably hurt the reburning ability. Thanks to all who responded.

 

[pen]

I don't know what your layout (as far as hearth pad / floor protection / floor in front of the stove) is like or even if the limestone can handle it, but I know that the hottest place around my stove is 2 foot in front of it. My stove is installed in my basement on a concrete floor. There are days I can barely stand in front of it in stocking feet because that concrete has has absorbed so much radiant heat through the stove glass. Any chance you have a similar situation? Maybe infront of the stove on the floor to absorb that radiant heat from the glass could be attractive and functional?

No matter how hard my stove is running, the floor is barely any warmer than ambient directly under the stove or anywhere that these massive hearth pads have to be built for some installs. It makes me laugh.

pen

 

[Wade A.]

Thanks Pen. Yeah, I built my hearth to Jotul's R value specs, and dimensions, and it barely gets warm to the touch underneath the stove. Talk about over engineered... it is waaaaaay more than you need. My floor in front also doesn't catch much heat. Really though, I'd rather it be that way than the opposite. I think I get more heat radiation back from my 3-sided alcove surrond, which is built to a firebox configuration and about 5' tall, travertine. That sucka gets toasty. I backed it with crete board mounted on steel rails.