John Fritz wrote:New to rmh but have not found any reference to life span of the steel barrel. They get pretty hot. Do they eventually warp or otherwise wear out and need replacement. If so, that would seem to be a fairly involved renovation, seeing how some designs have them embedded in the the mass.
They last far longer than in other barrel-stove designs, since they're not exposed to flame path.
Ianto Evans' stove that has seen the longest regular use is over 20 years old now, and has never needed to replace the barrel.
We do sometimes see warping of the lid, especially if a heavy cookpot is placed off-center during the heating cycle, on lighter barrel such as the food-grade barrels we like for their removable lids.
I think the heaviest barrels on the market are 16-gauge (1/16 inch). We don't see as much warping with these, though there can be a slight dome or dip effect as the center heats, returning elastically to original shape on cooling.
The fact that the heat is centered does seem to be an advantage to heating/cooling stress and longevity.
Between the slight warping, and common insurance concerns, upgrading to a heavier metal cylinder (such as 1/8" steel) would be sensible if you can afford it.
Custom rolled-steel cylinders with a welded top would probably run about $200-$300, the same as a new stainless barrel, and much stouter.
Once you are accustomed to earthen masonry, removing a few inches of earthen plaster to replace a barrel seems easy compared to the work involved in most other ways of sealing a metal-to-masonry connection. But fortunately, we don't have to take the barrels off very often either way.