When asked about the old Merlin gas burners that were made about 30 years ago I have always said that they either don't work very well and if they do they will melt the soft solder and destroy the gauge glass of the boiler.
Merlin gas burner.
Having assembled a Mamod locomotive from some bits and pieces made a hard soldered boiler with no gauge glass I tuned up a Merlin burner and fitted to the model. The model worked perfectly in the garden and on the garden railway track at the CMES plenty of steam and power. However its first run indoors at the Warley Model Railway show a couple of weeks ago after several circuits of the track; this happened.
Running outdoors, yes; but indoors far to hot even at its lowest setting gas setting. For an indication of how hot; the piston and the back of the port block.
Even the leading axle had 'Blued'!
The cylinder was taken apart and soldered together again and new packing fitted; oddly the other cylinder was fine and its packing in good condition. The parts of the model were cleaned and the frames painted with an enamel paint not the acrylic paint previously used.
Made a start on the ceramic burner; a new frame spacer to support it.
I think the shape of the Merlin burner created the problem; being round a lot of heat goes sideways. With luck I will get the chassis back together tomorrow and make a start on the burner. I have made many ceramic burners but never for a Mamod locomotive which will make is a little more interesting.
Regards Tony.
