Fireview Cookstone Surface Temp observations

[Slow1]

Some interesting (to me anyway) observations about my Fireview and the cookstones as they relate to the surface temperatures. I'm hoping that someone else out there may have them and may be able to report back their experiences with them too.

Background:

I bought the FV and at the same time bought a pair of the soapstone cook stones. For those who don't know these - they are perhaps 1" thick soapstone pieces that are cut to fit exactly on the top of the stove within the 'frame' of the cast iron surface. One goes on each side. I bought them since I planned to keep a pot of water on top all the time and also figured on cooking etc so figured it would protect the nice surface of the stove (can always replace the cook stones I figure).

I knew that these would take longer to heat up and thus the thermometer would lag on temperature changes (up and down). So to engage cat etc I would have to watch the flue temp as much as surface temp. Ok, no problem there.

Observation/experience:

Burning with the stones in place did indeed result in slower surface temp changes. I put the stones in place shortly after my burn in fires and kept them there 24/7 pretty much ever since. Now this is where it gets interesting. Once it turned colder and we went to 24/7 burning I noticed that although we were nice and warm I never got really high surface temps. In fact never over 450 generally, perhaps 500 once. I thought this was odd compared to what others reported as their temps... I wanted more heat from the stove if/when it gets really cold so wanted to know if I could get to 600 or at least 500.

The experiment:

I had a thought last weekend that maybe the stones not only slow down the heat transfer but may actually lower the max temp on top of the stove. Makes sense if you consider the air gap (small though it is) between the stones. So with the stove top steady and reading 425ish I removed the stone under the thermometer and set it down. (that was hard and interesting, hot stone to move!). The thermometer quickly registered a temperature over 550! It then settled down around 600. Hmm...

Rest of weekend I ran without the cookstones in place. Surface temps consistently ran higher than they had with the stone there.

Conclusion & Implication (?):

I am left to conclude that for my stove at least the cookstones are acting to significantly reduce the surface temp on top of the stone. Not too surprising really, but something I had neglected to consider before for some reason. I had expected that once the stove got up to temp the surface temp would get very close to what it would have been without the stone there - certainly not more than 150* difference.

Now I doubt this really makes much of a difference in terms of actual net stove heat output into the room but there may be arguments on both sides of that question. However, the critical implication of this is that if I'm using the cookstone, I can't use the surface temp on it as my guide for the stove's red line top safe operating temperature. I can only guess what temperature the stove would have to reach to get the top of the cookstone to 650* but it would certainly appear that it would be quite a bit higher.

Thoughts anyone?

 

[goofy]

Well you beat me to the punch on this one. I was planning on making a post in the next day or two named "cook stones kill heat" or something like that.

I have the Woodstock Keystone, so although not the same stove, very similar in many ways. On the Keystone, when you install with the pipe straight out the top, you are left with an 'extra' square stone (would go on the top if the pipe were to go out the back). I initially used this stone to put a cast iron kettle on the stove top. I later switched to a cast iron steamer, because it put more humidity into the air than the kettle. The steamer evaporated about a gallon of water a day. Our house is pretty dry in the winter, so I figured if one steamer was good, two would be better. So, I ordered a pair of cookstones from Woodstock, so I could put a steamer on each side of the top of the stove.

Keep in mind that the top of the Keystone is a bit different than the Fireview. The top is pretty much split into thirds, instead of two halves like the Fireview. The 'extra' stone I was using for the single steamer sat in the middle front of the stove top. The newer setup for the two steamers had the middle cook stone removed, and two new stones on the outside thirds of the stove top.

After the change, the first thing I noticed is that the middle of the stove top where the initial single stone had been was MUCH warmer that it had been with the stone and steamer there. It now puts out the most heat of anywhere else on the stove top. The two outer thirds with the cook stones and the steamers now were putting out significantly less heat than before. I thought that once the cook stones got up to temp the net output of the stove would pretty much be the same, but it wasn't. Ever after keeping the stove at 400+ degrees all day, the two outer thirds with the stones never put out the heat that they did before the cook stones were added. I ended up removing all the cook stones and steamers, and now the stove puts out a noticeably larger amount of heat.

What I have concluded is that soapstone makes a better insulator than a conductor. If it were a good conductor then it would behave more like cast iron and easily and quickly dissipate its heat. Since those stones are insulating the top of the stove, more of the heat is ultimately going up the pipe, and not radiating into my house.

Trust me on this one, unless you really want to cook something, leave the cook stones off the stove top.

PS. I now run a humidifier to replace the duty of the steamer(s).

 

[MacPB]

Slow1.

Thanks for your observations and valuable feedback for this stove.

When I order a cooktop stone from WS, I want to see if they can customize it a bit(I'm willing to pay for it). I want to have a 3-5" hole "punched" out so that I can put the steamer on it as well as get higher temps for a pan, pot, etc. when I need it. I would use the other flat area of the coook stone for simmering at lower temps.

I would also like to to have the perimeter (about an inch inset) mitered out to created a recess or groove sort of like a chopping board to catch any liquids before they go on to the stove top.

Mike

P.S. I have not got around to trying that oven out yet (I hopefully will soon).

 

[Slow1]

Wow, that's a lot of customization there!

I've heard the stone is soft enough you can work it with 'normal' woodworking tools... although I bet even working with a talc-based rock such as this will dull blades pretty quick. You may just want to work it yourself. Good ideas though!

For my part I'm simmering my water directly on the stove surface now and will use trivets for cooking on top and generally just be careful of the surface. I may or may not use the cookstones again for their intended purpose... last night I used them as bed warmers and that was rather nice really - got me some points with the wife anyway.

 

[Backwoods Savage]

Wow. That is about what I figured might happen. It begs the question: where is all that heat going if not transferred through the stone? Probably up the chimney which is a total waste of energy.

Since we've had our stove, we also have had the boot driers. These are just small soapstone blocks about 2" x 7" and a little over 1/2" thick. They come in pairs (so do feet). We also have the smaller ones which are about 1.5" x 6" (I think. I should probably measure). When we cook on the stove (daily now) we always use these to set pots and pan on. It seems to work fine. We also always have water on the stove to help with the humidity as I really do not like the regular humidifiers so will put up with some dryness. But then, my wife also likes to dry clothes by the stove after washing. That really helps with the humidity and saves on the electric bill too.

And earlier today I took one pair of the boot driers with me to the woods while cutting wood so I'd have a nice warm pair of gloves to wear when I finished. That is super nice.

 

[MyFyrByrd]

I have also purchased two of the cooktops to protect the top surface from scratches. Like Goofy said , when using these, alot more heat goes up the flue. I'd like to try a test: Get the stove up to temps (450 to 500 degrees) without the cooktops, then record the temps on the stovepipe. Then place the cooktops on the stoves surface. I'm willing to bet that you'll see a change in flue temps within a short time.

 

[MacPB]

last night I used them as bed warmers and that was rather nice really

(broken link removed to http://cgi.ebay.com/Antique-SOAPSTONE-Handled-Buggy-Bed-Sleigh-Foot-Warmer_W0QQitemZ350217524608QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item518a975580#ht_2007wt_1167)


That's actually something people in the old days used it for.

 

[rob bennett]

I ordered my keystone with an extra set of top stones. They told me that it would basically cut the heat out the top in half. I got them anyway since it was free shipping and it gives me more options. They recommended that I buy 1/2 inch stones that don't cut the heat down as much. The gas stoves use the thinner 1/2 inch soapstone.