Many thanks to Obvious for sharing the following about an unfueled test. I think reports like this can be very valuable for replicators and replication students. This was originally posted on this thread.
A quick summary of a test last night (no fuel):
I added ceramic paste to the outside of my tube that has been run many times, that has a thin enamel coat “wetting” the coil to the tube. This was before deciding that the paste is a bad idea, and it was already baked on, so no going back. I will do a proper data analysis later (bit busy right now), but these are the notable parts.
The temperature delta between outside and inside is greatly increased. I could formerly get the exposed surface to vey close to the interior temperature. Now it is very much lower in temperature.
The delay period of both thermocouples to reaching a steady state takes much longer. I would guess the time period has doubled, maybe more. This is due to increased thermal mass, no doubt. At higher temperatures it seems less noticeable than lower temperatures, but it is significant.
The interior temperature was greatly increased at the same power level. This might seem like a good thing, but I think it is very bad. My previous maximum temperature was about 780°C, now 1075°C, at around 523 W.
I think it there was a LENR event at my current maximum temperature, the tube would fail, the contents would boil, the coil windings would melt, the TC maximum rating would be exceeded (in no particular order). The interior heat cannot be removed fast enough with exterior insulation, and there is now a long delay before it would be noticeable. If I were to bring the exterior to 1200°C, then the inside would be well over 1500°C now, maybe much hotter.
I think that NO EXTERIOR INSULATION would be best for testing, and the coils should be designed to make the correct heat externally. The inside heat will be hotter anyways. This way coil problems can be seen, the coi ls will remain oxidized properly, and internal heat will not cause instant failures. If any insulation is used, it must be very thin, very high heat conductive, etc.,until other problems are sorted out.
The tradeoff for higher inside heat with exterior insulation is poor heat release to the outside. If excess heat occurs at a rate that the heat cannot be conducted away, there will be certain failure of the device. Maximum heat radiation is required for successful experiments. Any quality PID control of heat needs the most fast-acting, lowest Delta T, and representative temperature reading it can get.