Hi all; Been living with and loving my rmh in the greenhouse for almost four months now, thought it was time to open it up and see how the cast chimney is holding up as well as how much ash had built up in the manifold. After inspection, things couldn't be better! Using a piece of 8" soni tube as a sacrificial form for the cast chimney worked perfect ! Ash buildup after four months was minor ! Just recently added the last lift of cob & rock into my mass and its drying fast. originally I was getting top of the barrel temps of over 1000 and side temps of 750 now with the mass drying out and holding more heat I am still reading temp over 1000 (as high as my digital gun goes) and side of barrel temps are in the 850 degree area!!! Have not gotten the barrel top to glow orange yet but.... I have had wear issues on the feed side of my cast core , using waterglass I was able to patch worn areas back to good as new. I am considering using all refractory for my next casting, cost will be considerably higher (100.00-150.00) but if the wear problem is gone then the longevity will make it cost effective. Bottom line is I don't know how I went all these years without a rmh and now that I have been enlightened I will never be without one again !