Thirty three years ago, in 1978, Jeanne and I bought a compact L. Lange Model 6303 wood burning stove for our apartment. It went along with us to our new house in Ira in 1984 and has been keeping us warm ever since. Last year it was showing small fissures in the seams between it’s cast iron panels and we knew it was time for a major overhaul. I tried smearing furnace cement into the cracks but that wasn’t working. To recaulk the stove it had to be taken apart.
L.Lange, a Danish company, made their stoves from premium cast iron as is evident in their durability and engineering. Because the stove weighs over three hundred pounds I took it apart, and later, reassembled it in place. Only eight short bolts hold it together and all but two surrendered to my wrench. Those had to be drilled out.
The original caulking between the stove panels was very deteriorated and the panels pried apart easily. Now I could start cleaning them. I used a small air powered chisel but hand tools would have worked too to remove the remaining baked on caulk from the mating joint surfaces. Joint surfaces should be cleaned as close to bare metal as possible, I used a wire brush after chiseling and then sandpaper to expose the base iron. There were fifteen panels to clean and the job took me a few hours out on the lawn making noise and dust. I wore a ” nuisance” style paper dust mask because of the caustic dust.
To reassemble our stove I bought Rutland brand furnace cement, made right here in Rutland, Vermont, a silicon and alkali mixture which bonds metal to metal, perfect for stove repair. I used two 10oz tubes for a caulking gun, plus a half pound container in the course of the job. The caulking gun made filling the long joints on the panels easy with little mess. The contents of the bulk container spread into the wide joints between the stove’s arched side panels with a putty knife.
To make sure the assembly went right I put a series of the panels together without caulk and marked them one to the other with a fine chalk mark, then laid them out on drop cloths. That is important because the caulking compound is chemically aggressive and will permanently etch any ceramic or glass it dries on. We have ceramic tiles under the stove and I learned this the hard way. Wearing rubber gloves is recommended.
Application is pretty simple. Wet the joint surfaces with water (I used an old paintbrush) then apply enough caulk to fill the joints when assembled. Then put the panels into place lining up the chalk marks and any bolt holes. Remove excess caulk that squeezes out of the joints to use on the next panel and smooth the work. If any caulk gets on an outside surface it has to be immediately wiped off and the area washed with warm water. Rutland’s refractory compound is permanent when it dries.
After more than thirty years of heating our woodstove had some slight warping which resisted reassembly at the final stage. I solved that by using two wood clamps to bring the panels into alignment and locked them in place with the last bolt. In a couple weeks, if cool weather arrives, I’ll light a small fire in the rebuilt stove to set the refractory and then it will be ready to heat our home for some more winters. In the meantime it needs a new coat of stove blacking, and that’s for a rainy day.