Having had a couple of people take a look at the boiler I have for the Britannia, I have decided not to go for closed flue firing and instead use the Stephenson's approach with a blower. Seeing as no-one else has the same boiler and firing method I am somewhat starting from scratch here, however, I have effectively made a much larger version of the Dee burner, with two secondary air holes. Copper sheet and tube, silver soldered throughout. Ceramic grate at the top. Finished this evening and yet to test it!
