Morning all. Owl reporting back on the adventures of the chimney variety. As mentioned, the rusting flue on Bunny the Boiler finally kicked the proverbial bucket. There was glowing metal and whisps of flame and it was all very exciting, though entirely unsafe so we switched her off, and chopped it out.
Then there was some research to do. Bunny has a 6″ chimney connection, but the old flue was only 4″ wide. Here is the rusted horror that was, big to small…
I quickly discovered the 6″ to 4″ reducer was anything but standard. Several conversations with flue suppliers and heating engineers made it clear that reducing the flue is generally not advisable. This was good news because it meant we should use standard 6″ flue pipe (cheaper than custom). We ordered a whole lot of 6″ twin-walled flue parts from the nice folk at Flue Supplies which arrived the next day in several massive boxes.
Then we had to figure out how to cut a bigger hole in the deck above the boiler. Our friend T is masterful at making things in metal and wood, and also at lateral thinking. He had mentioned plasma cutters and oxy torches before but such things are expensive to hire and require some expertise to achieve a good result. T came to the rescue with a super simple way to cut the flue hole involving a drill, a jigsaw and an angle grinder.
First I had to cut the old flue collar off. This meant making a load of sparks with the angle grinder (unashamedly my new favourite tool).
T had swiftly knocked up this template for me in his CAD software…
…which I taped down and hammered each centre point with a punch. Then it was time for a meaty drill (with one of these attached) and making more noise.
After about 20 minutes of drilling I had something that looked vaguely professional.
The jigsaw swiftly cut between each hole and around the weld on the far side.
Then more making of sparks with a thick cutting disc to smooth out the sides…
…and we had a new flue hole.
The only remaining problem was the rain. We needed a new collar to stop water running off the deck and through the hole. T again came up with a very lateral solution – butchering a large saucepan. On the promise of steak and red wine for dinner, he generously brought his MIG welder over and we got to it.
The large saucepan had its bottom chopped off…
T took five minutes aside to make a new saucepan prototype… (work in progress people)
…before getting down to the tricky job of welding thin saucepan metal to a heavy steel deck. With red wine and steak in his near future it didn’t take too long. The results look pretty damn good in the cold light of day.
…so bar one support bracket (which I’ll fit tomorrow), this is the final result.
Incidentally, T also helped us make the main stairs removable so we can start work ripping out some redundant wooden (?!!) water tanks, but all that will be in the next post.