Ash Cleanout

I've watched some of your short videos about the rocket stove mass heater and I have a question. On the video for the day and a half workshop, you showed a cleanout on the far side of the ductwork. This cleanout was eventually moved closer to the combustion chamber. My question is this: shouldn't the cleanout be located right under the combustion chamber, or maybe in front of and inline with the feed end/short end of the J-tube, which is horizontal for 5-6 inches, then goes up into the tall end of the J-tube? That way you would have access to use a long-handled ash shovel to scoop out the ashes from the combustion chamber and wood-feeding area. If you have the cleanout after the combustion chamber/barrel, then there's no way to get the built up ashes out of the combustion chamber. Besides the ashes eventually building up too high, I want those ashes for my compost pile. We have a Woodstock soapstone stove that is over 90% effecient, but there are are still ashes we have to deal with. Or, is the rocket stove mass heater so efficient that there are no ashes to remove?

Barry Pulley : Wood should be fed vertically down into the Rocket Mass Heaters RMHs Feed Tube, at no time should there be more than a tea cups worth of
ashes forward of the Feed Tube, adding more wood in this area (which is about he only way that you could have ash in this area) will constipate your Rocket
and hurt performance. As you will only be burning your RMH for a few hours at a time once or twice a day, getting in there with a small coffee can or large
soup can with one flattened side might be needed every other day or so !

Your other stove will produce a gritty ash with some large pieces and some charcoal, the Fly Ash made in a RMH, is as light and fine as talcum powder and will
be carried through your burn tunnel, up the heat riser and will (mostly) settle out into the ash pit below your Transitional Area where the vertically failing gases
are funneled at right angles horizontally out to your Cob thermal Mass Bench! With a large enough ash pit below your Transitional Area some people go a couple
of years with out any cleaning ! Y.M.M.V.! Hope this helps and is timely !

Barry-
As Allen said the clean outs are for the fly ash that accumulates downstream of the actual combustion in the RMH core. Minimal quantities but some method of clean out needs to be included in design.
As far as ash in the feed tube I can tell you this it is highly dependent on the quality of wood you use as to how much of a problem ash buildup can be.
Allowance for an ash pit and clean out of the feed tube (and perhaps the burn tube) is a somewhat neglected point in most discussions of design in my opinion.
I have an ash pit at the bottom of the feed tube that is 2 1/2" deep (full brick width on side) and about an inch further into the burn tube than the top and I still get a fair amount of ash in the opening of the burn tube. I'm using a P-channel too which aside from it's intended benefit helps a bit with ash in the burn tube. I can't burn much of the huge supply of very old almost rotten (but dry) wood I have for more than maybe 2+ hours without my burn tube becoming nearly choked off. I have to let the fire die down and shovel out the coals and restoke it. Even with the best seasoned oak I can only go maybe 4 hours. An unfortunate requirement for my RHM in a greenhouse during the freakish cold 0-20deg range days here.
Bottom line I plan on including a feed tube ash pit clean out opening for any future RMH build. It's easy to do and there's no reason not to. Lets face it ash is going to build up in the feed tube why not make it as easy to clean out as possible.

John Adamz : Everyones rocket stove is different, indeed to identical seeming rocket stoves will create their own unique characteristics during their build, I
would not consider your RMH and its Ash accumulation to be typical, but we use what we get. With the lighter fire brick we sometimes get more ash at the
end of a "Burn'', but I have no thoughts on why, other than Wood types and the amount of bark you burn to explain your RMHs 'manners at the dinner table'

I have no problem with Ash pits or Clean Outs for the front of your RMH, merely wanting them to be air tight! Nothing i have said ether changes what said
earlier or reflects on anyone else's RMH, I would sooner tell someone their first born was Muf'uggley ! For the good of the Crafts! PYRO-Logically BIG AL

It is amazing the differences in performance and efficiency that result from very similar designs of RMH's. The type of wood burned plays a HUGE role. I honestly can't see how a plain J-tube with no ash pit at all at the bottom of the feed tube wouldn't clog up the burn tube even after only a couple hours with premium wood. I guess cleaning after every use might be the price to pay for the simplest design.
All of the oak I use has no bark, the other old misc wood has very thin bark. Maybe I should clarify to mean hot coals building up before they turn completely to ash. Even with the most exceptional wood I use that produces maybe 1 1/2 qts of ash in a day of burning in the house insert I'll get about 1 1/2 cups of ash after completely burned out from ~3-4 hours burning in the RMH.

I would agree that a cleanout would be necessary after the burn chamber also, but it sounds as if my concern about the buildup of ashes in the feed and burn tubes is valid. If the author/creator has used his own design to build RSMH's in his own house and has built as many RSMH's as he/they have, then certainly somewhere along the way, this issue would have come up and been resolved. And somewhere in the four DVD set and in the plans there would be provision for or mention of that. I don't mind paying $100 for the set, but something as basic as a sensible location for this specific ash cleanout has to be there. I don't want to have to reach into the feed tube with a cup or anything else to scoop up ashes, because there will be ashes between the feed tube and the burn tube, as well - which will be difficult to get to. I can see it now: my wife finding me with my arm stuck in the feed tube up to my elbow as I was trying to get to the built up ashes in between that point and the burn tube.

So, is there a better location than where I suggested in my original post? If so, what would be the best way to accomplish this? Ernie and Erica Wisner, is this information included in the 4 DVD set?

Barry Pulley : this is very much like you wanting a second opinion from your Doctor and the Doctor selecting the one HE wants you to see, but as I assisted
on the construction of this one with Ernie and Erica, and it turned out similar to my experience I wanted to give you the opportunity to see this !

In the Listing for all rocket stove forum threads with most recent listed 1st find and click on Video: Great Rocket MassHeaters in upstate N.Y. & Quebec,
it is the first one I want you to see, A look at Chellies' . . . . . this is more inline with what I have found, most of the fly ash ends up down stream and outside of
the Barrel, and i think my RMH has a stronger 'Pull' BIG AL !