Hi Steve, I have a corner "Bubble" with a back boiler. (Thirsty Brute!)
I used to have burning problems and thought is was due to poor air draft. I eventually found that I had a partial air lock in the fule line, which is a long run, (Partial fuel starvation). I cured this by creating a vacuum with a Pela oil pump. This sucked the air-lock through with the diesel at the fire connection end. Since then, I have hed no furtheer problems, even in the very strongest stormy gale force winds. I tried a long flue (Up to 6ft experimental when moored). This didn't help much as the flue gasses cooled too much. I then fitted a 180mm Marley plastic soil pipe around the stainless 100mm flue pipe and this did make a big difference. I fitted an 18mm think hardwood ply collar between the inside stailnless flue and outside plastic soil pipe tube. I was apprehensive about the plywood catching fire due to hot gasses. However, apart from some very local scorching, all was OK. There was never any chance of the plastic overheating unless it came in contct with the metal pipe. Now that I have found and solved the fuel supply problem, I find that I can run the "Bubble" stove OK on a short (cruising) 2000mm flue pipe, single skin. The above measurements apply to the length of flue above the boat roof AND I have an Anti-Downdraft fitted to the top (The cylinder type commercially available) which are about 150mm long and a much larger diameter than the 100mm flue pipe, with spigot to fit pipe. I don't know whether any of this information is helpful to you, but it is posted in the hope that it will be. ***A note: I thought all along that my problems were flue probs. This was in fact not the case and I spent unnecessary hard earned cash spending out on the wrong thing! ~Allan~
