Cleaning out the exhaust system on the Jumbo involved some serious surgery.
The exhaust system comes in three parts; the front pipe, mid-box and the rear can.
The front pipe was corroded by in a useable solid condition, with the mid box complete but full of carbon from 15-20 years of use. The end can had had open-heart surgery in the past, and was in a rough state. I’d sent the exhaust off to Redditch Shotblasting along with the frame and other bits and they shotblasted then spray the parts with PJ1 Black Satin Engine paint (ie heat resistant paint).
In an attempt to clean out the rear box, I’d swilled around some paraffin in the box, then moved it out of the workshop into a the field. I took the blowtorch, attached it to a long stick, lit it and applied to the end can. The resulting explosion only moved the end can a couple of feet, didn’t split it, but for sure loosened the crud inside the exhaust.
However, still thought that end can some needed some attention, so decided to cut out the back plate and weld on a new one. Remove the packing at the same time, as it was completely knackered. Then, with some trepidation, decided to take the air saw to the till-now virginal mid box. Allowed me to clean it out and again removed the packing.
Both welded neatly by Pete and then sprayed again with PJ1 Satin Black, three coats and with the space heater in the workshop cranked up to get up the required 21 C for spraying.