Jock Simpson

Could a hot plate be built on the burn tunnel of a jtube or would it prevent a clean burn.I am building a Tim Barker style hot water heater and would like to incorporate a hot plate.If it’s inadvisable on the burn tunnel Does anybody know of a method to incorporate one . Thank you?

I have a J tube I built 2 years ago That has a bell over the riser tube with soft 15mm copper tube 15 m long coiled around it. It has done stirling service but now the steel riser is starting to disintegrate,hence my decision to build a new one.The firebox was larger and taller feeding a 6 “ pipe as burn chamber and riser.  I suspect that this is why it didn’t get as hot as a 6” rocket can get probably fortunately as I have always had a concern about the copper pipe melting,hence my reason for a new design and my question “How critical are the correct dimensions?regards Jock

I am planning on building a 6” j tube water heater along the lines of shown on various forums by Tim Barker and Geoff Lawton.I have what appears to be good soil for making bricks which has25 to 30% clay and 65% sand and 5+% silt.I  have made some green bricks in a mould and they air dry with minimal cracking.I want to make enough to Build my rocket with the air dried green bricks and fire up the rocket to cure them in situ.Anyone who maybe done this or foresees a problem with this please comment.Thank you in anticipation