First I tried the Sievert 2943. I tried different gas settings, and different positions of the burner in the fire box. I quickly discovered that an opening had to be present next to the supporting flange. Despite that, steam was produced in 10 minutes, and 20psi was achieved in 15 minutes. My aim is to obtain 40psi, and maintain 40psi during engine operation.
Unfortunately this burner does not work if there is any significant back pressure in the system. Stuart has advised me to try the Sievert 2954 which he says will cope better with back pressure. The Sievert 2954 has a similar appearance to the 2943, so I have not photographed it.
I have borrowed a Sievert 2954, but it needs some setting up, so I thought that meanwhile I would try a burner style which had been mentioned earlier. It is a tube with multiple transverse slots. Despite being constructed rather roughly and quickly, it produced a good hot flame. Perhaps a bit small, but promising.
If the next Sievert is not satisfactory I will come back to this style, and experiment with different slot numbers and sizes.
If you are becoming a bit bored with all of these gas burner experiments, I understand. When the burner is finally sorted I will be delighted and relieved.
I have machined some wood to be used for lagging. It is West Australian Jarrah. A dark coloured wood which is often used for exterior flooring. I will apply it to the boiler soon.