I think I need to describe my all my problems clearly so you could diagnose my RMH:
1) From the beginning, I had exactly same problem as in the link Satamax gave: Which is at the begining my RMH burn at the tips of the wood and very nicely. But after burn for a while, my feed tube was so crazy hot that the minute I drop the firewood in, it ignited either full length or very long part of the wood (I had to wear helmet when came near the feedtube so it won't babecue my face). When I saw the link from Satamax it had my exactly problem, I thought after I cool down the top layer of the feed tube just like they did, I should be fine. But after I stripped off the insulation on second layer of feed tube, even my feedtube is not crazy hot and I had better temperature, but still have red charcoals and some burn up
2) I then changed my feed tube 2nd time: used half size bricks at bottom layer and full size bricks at second layer. Satamax and Glen advised bone dried small hardwood at first then big wood and Shilo advised more length to the chimney with cap. I already borrowed the ladder to claim up the roof and bought the cap (please take a look at the photo to see if it is ok). I don’t have any one to help get up on the roof yet. Hopefully next week.
3) Today temperature is 90 degree, but I would want to test about the wood may give red charcoal and I would want to see if changed the size of the bricks on the layer of feed tube would help my RMH. So, I burn 3 loads of small finger sized woods: First and last load with hardwood purchased from hardware stores, and middle load the same wood pick on the street and I used them previous burn. Here is what I find out:
• First load with purchased hardwood: Burn was reasonable at the tips, after burn for a while, I don’t see crazy hot feedtube ignites big part of wood as it did before, neither burn up - good
• The second load (same wood used before): it burned up, burned quick, and turned in to a whole ton of red charcoals.
• The third load, I went back to the type of wood as the first load, burn was nicely at tips: no more burn up and not much red charcoal
• After 45 minutes burns, my feedtube was reasonable hot, not crazy hot, I measured and I had only 525 degree
Here is my what I think:
• So, beside my feed tube was too hot, the wet wood or the type of wood is another reason I have burn up and red charcoal. When winter comes, I think this problem fix itself as my wood have more time to dry off
• I burned three loads, about 45 minutes, but the temperature is only 525 degree. What happen? I should be above 630. Last time after the first fix of cool down the feedtube, I burned 45 minutes and my gun gave me 630 and then after that “OH” which mean temperature was higher than 630 degree. This time it’s only 525 which is worry me a lot. What happen? Please help, 525 is not that nice
• I already insulated the 2nd and 3rd clean out, but the 3rd clean out still dripping. After stop burning for one hour, I opened the 2nd clean out, and there was water inside, little, not much to drip outside but inside there was water.
Question: If my thermal mass doesn’t have enough clay, what kind of problem it causes my RMH . I saw Paul Wheaton used only sand for his RMH. So, if sands alone is ok, then not enough clay should be ok too, right?