Many years ago we bought a soapstone stove at a garage sale for $25. It was not in the best shape with numerous stones broken. I brought it home and dismantled it so I could move it. The complete stove weighs around 700 pounds. I stored the pieces in the barn. Now that I am retired, with a little more time on my hands I decided to fix it up and install it in the house. I have a lot of wood and it would be nice to have a backup for the propane heat we have.
The stove is a Hearthstone I made by the Hearthstone stove company of Vermont. I believe that the Hearthstone I is the first model made by the company and is no longer in production. I did learn from an online dealer that the Equinox 8000 stove replaced the H1. It looks similar but the innards have been modernized.
Replacing the stones
The first task was to see if it was even possible to replace the broken stones. A few years ago I visited the local Hearthstone dealer and asked about getting replacement stones. They said I should talk to the factory. I contacted the factory and they were kind enough to send me an owners manual for the stove but said I had to go through the dealer to get part. The old run around. The factory would probably have had to make the stones and that would be and expensive way to get the stones. I did find an online dealer that had some of the stones but they are quite expensive. One valuable thing I got from the online dealer was a chart showing the layout of the stones in the stove. That leaves me with getting some soapstone and making the stones myself. It turns out the stones are 30 mm thick which is the same thickness as the soapstone slabs used for kitchen counter tops and the like. There does not seem to be any soapstone counter top dealers nearby so I have been contacting soapstone suppliers. I got samples from three suppliers, Finnish soapstone, Brazilian soapstone and Virginia soap stone. I wanted to match the look of the old stones. Shipping turned out to be quite expensive for the stone so I finally found a dealer a few hours drive away in Wisconsin. The slab I purchased there does not match the stones of the stove but arranging the new stones symmetrically it will look OK.
The picture above shows the broken stones. I used this to estimate the amount of new stone I needed to purchase. After I got the slab of new stone I realized that I actually needed more stone as I wanted to move the flue outlet from the back of the stove to the top. This requires a few different stones, which I have to make. To compensate for this I decided to glue the stones with simple breaks and no missing parts. This is a stove and the stones get quite hot so you can’t use just any glue. I have a gallon of sodium silicate which can be used as a glue. Sodium silicate when dry is essentially glass and can withstand high temperatures. This worked quite well and after refinishing the stones the breaks are hardly noticeable.
The picture above shows the method I used to cut the new soapstone slab into the sizes for the stove. I put a diamond tile saw blade in my circular saw and cut the stone wet with a clamped on guide. This produced a nice smooth cut. I was careful not to get the electrical part of the saw wet and it is plugged into a GFI outlet.
I planned on cutting the grooves and bevels for the stones on my table saw with just an ordinary carbide wood cutting blade. I tried cutting some of the broken stones to see if this would work and they cut quite nicely. When I went to cut the new stones they promptly ruined the carbide blade. The new stone was much harder than the original soap stone in the stove. A 10″ diamond blade for the table saw solved that problem.
Each stone has a decorative beveled edge and grooves in the edges. Flat metal strips fit into the grooves to hold the stones in place.
After sitting in the barn for years it was impossible to remember how all the pieces of the stove fit together. It was a jigsaw puzzle type of challenge to sort out the stones and metal parts. The metal parts had become quite rusted.
As can be seen in this picture of one of the stove doors. All the metal parts got sandblasted and the cast iron parts repainted with flat black high temperature stove paint. Some parts like the screen for the doors had to be replaced. I replaced the screen and all the nuts and bolts with stainless steel. I also had to replace some of the steel strips that hold the stones in place because I changed the vent from the back to the top of the stove. This requires some different length strips. The ugly bolts in the door handles were replace with some stainless steel rod and some nice brass acorn nuts.
Because the complete stove weighs somewhere around 700 pounds there was no way I was going to assemble it and then move it into place.
In the picture above the base of the stove is placed along with some of the internal workings. There are cast iron plates and a channel around the bottom that supplies air around the base of the fire. The incoming air is regulated by a thermostatically controlled damper on the back of the stove. The 400 pound water filled cast iron radiator behind the stove provides and excellent radiation shield to protect the wall behind it from the stove heat. Not seen in this picture is another metal radiation shield on the right wall.
Above is another view of the stove being assembled. The three stones in the back with the fiberglass screen on them are some of the replacement stones. The original stones were shorter to allow for the vent in the back. You can also see the ends of the steel strips that hold the stones in place. Because of the way the temperature of the stove is regulated by controlling the incoming air it is important that the stove be airtight. The rope gaskets for the doors were replaced. New ceramic fiber paper gaskets between the door frames and the stone were installed. When assembling the stones into the stove each stone mortared with furnace cement to seal all the joints between the stones and between the stones and the cast iron frame.
Above is a picture of the completed stove with a nice fire going. Normally I use the side door for ash removal, loading wood and starting. This winter I have been using the stove daily. It will keep the downstairs part of the house warm without any additional input from the propane heat even on below zero days. When the temperature is in the 40’s it is easy to get the house a bit overheated. Because of the way the air is regulated I believe you are supposed to be able to load the stove up with wood and have it burn most of the day. I prefer to keep only a small amount of wood in the stove and add a piece every hour or so during the day. This way if it gets too warm I can just stop feeding it wood.
Since the stove is in the dining room it can be used to keep food warm. Here it is keeping thanksgiving dinner warm.
The dining room gets a bit warmer than the rest of the downstairs so I have a fan to help circulate the air to the other rooms.
Hearthstone stove manufacturer http://www.hearthstonestoves.com/
Soapstone supplier http://www.elegantstoneproducts.com/