So I tore open the stove and while doing so tore off the duct pipe clay also. I realized there was still cardboard covering part of the duct pipe opening! So that gave me a glimmer of hope I can still create more of a chimney draft to suck up more smoke.
The problem is that the Silverfire is designed as an outside stove. It is considered best to run it with the front door closed. But there is also a "ramp" to feed the twigs into the fire. So the implication is you have the door closed enough to cover the twigs that are on the ramp, being fed into the fire, as they burn down. So the door is never totally closed.
But that assumes the Silverfire has the chimney effect from the stove being open, thereby pulling the air straight up and burning off the oxygen from below, as a real rocket stove would then burn off its own fumes by pulling the oxygen down, from below.
So I figure it is next to impossible to run the Silverfire indoors without smoke coming out of the door - unless I get some amazing chimney effect from the duct pipe, which I doubt. The smoke didn't seem to get pulled out of the duct pipe but rather lingers at the duct pipe exit. So that means it is more pushed out and that is how the rocket mass heater works as well. So then I need to extend the duct pipe another section - since the smoke was still too close - and the question is will the rocket fire be able to "push" the smoke out that far. I think so, especially now that I redid the duct pipe opening, after making sure to clear out any last bit of cardboard.
So I then opened up the stove opening and I put a metal pot lid sealed into the clay - with enough space - about an inch - for smoke to move over to the duct pipe. I then used a clay flower pot base to cover the duct pipe - inserted in the clay mold.
I'll take a photo when I get a chance - I buried the duct pipe that I have and will have to get an extension of duct pipe. But first I want to see if I get better chimney effect draw of the smoke out from the Silverfire stove.
In the mean time when I began wondering the "nutritional value" of smoke I realized the fumes were getting to my brain. haha. So I cooked up some shiitake and drank some stinging nettles juice. A comment on youtube:
they all seem to make the mistake of having the door open during testing and review, either because the fuel used is too long and keeps the door open, or by propping it completely open. You actually managed to make both mistakes in the same test. This ruins the oxygen feed, convection dynamics, and temperatures the burn chamber is designed to create. This results in lower burn-chamber and therefore cooking temperatures, as well as making it very inefficient.
2. Do you see that little metal thing on the door? The literature says it's a fuel gauge. All of your fuel should be thin enough to fit into that little circle. About pencil-thin, or slightly bigger. The fuel you both started the fire with, and used throughout was too thick. The Silverfire is essentially meant to be a disaster preparedness asset. It runs on whatever twigs, wood chips, or pine-cones that might happen to be around someone who is in that kind of situation, and needs the ability to do a fair bit of cooking safely, (think people starting fires for warmth and cooking in or around collapsed buildings)yeah so the draw improves once the stove is hot. I'll have to try it again, now that I cleared the duct pipe out and it is overcast outside.