Rocket mass heater Drum lifetime?

How long typically does the drum last before it needs to be replaced? Or does it ever?

Ivan the information I have comes from Ernie and Erica Wisner and comments made here at permies.com by other members, with ~ 100,000~ made word wide, and many
now over 20 years old we have reports of barrels being replaced by their owners through an excess of caution, and zero reports of any failures !

Interestingly the Heat Exchangers in Commercial Fossil Fuel Fired Forced-air Furnaces, and that is what the Rockets barrel is, a Heat Exchanger, is made from lighter gage
ductal steel than the gage of ductal steel found in modern barrels, and the commercial models usually have a 20 year warrantee !

Good news all round For the good of the Craft! Don't be the Marshmallow ! BIG AL !

Thank You

Pretty sure that I have seen photo examples of damage occurring to barrel or other parts of the system on this forum. Probably due to poor construction or unsuitable materials. Can't find it in my bookmarks, tho. I remember it was a barrel with a removable top, so they were able to access easily and I think replace the internal chimney.

Looking forward to building one (55 gal system) in the backyard in 2014. My barrel is already rusty after storing outside for a year (paint burned off). Love this forum... jeep up the good work!

Peter Gallo & Permies Cloud : Perhaps you are talking About Rob T.s Experimental build ( You Tube Web 4 Deb) that had a total heat riser failure and started to burn the concrete
bricks/pavers!

The inside of the barrel was heavily sooted up except directly above the damaged heat riser that channeled hot enough Exhaust gases to keep this area Clear, even though he
had had a Radiator failure at a previous misadventor that allowed a scale of rust to form on the outside top of that barrel. I believe that that barrel was pressed back into
service and not replaced, -I will check on that soonest ! Big Al