Thanks for the link, I was using slightly different values. So maybe after a few tries it will work. I'm currently using about 0.1M salt and 20 mA/cm2. Not sure if the cathode should be fully submerged (is easiest to let it stick out of water). Maybe best would be plate-to-plate with small gap?
My nickel is Aliexpress "99.99% pure", obviously could be bad.
Does not seem to be too easy to replicate, this time tried 48 h electrolysis with tap water and pure nickel cathode + Pt plated bar anode -> 0V. Easy improvements might be using distilled water (car battery water?) and somehow doing 2 hours of drying in hot (60 degrees C?) plate. 1W power for electrolysis sounds unclear, 1W per how much cm2? Current per cm2 maybe clear enough? Used K2CO3, but how much molar per volume? I'm also not sure if there should always be oxide coat (by heating or with electrolysis)?
What happens for example if you do electrolysis for NaCl + water, with graphite anode + cathode? I tries this, and noticed that it produces H2 and Cl2 gas, but after a while there is some kind of balance, where no gas comes out of the jar, and there is still bubbles forming, but they get absorbed back to electrolyte. So what does the electrolyte contain? Also i have used acetic acid, and i guess more or less the same thing happens here?
Comment to this paper: https://www.lenr-canr.org/acrobat/RoutRKreproducib.pdf
The oxygen helps electron emission, for example oxide layer is used in gas-discharge lamps. Or lack of oxygen works as barrier for electrons. Test with x ray film should be done again so that oxide layer is always present. Then i guess vacuum works best?
About the "mysterious radiation": i think the mechanism is the same as in thermionic emission, but in case of fusion, each fusion event throws a few electrons out of lattice, and temperature does not have to be high. So in both cases lattice vibration causes electron emission. Not so mysterious after all? Lenrionic emission? With thermionic emission, if temperature is low, no electrons will escape the lattice, and if temperature is high enough, there will be constant flow of electron emissions.
1. I used about 5% HCl, but now I think brass is a problem, and i will use pure iron for anode and cathode in future.
2, With HCl, voltage was like <0.5V, and i used current limiting.
I tried this with iron plated on brass and got no current or voltage, questions:
- what should the current density be? i tried with 1 mA/cm2 and it does not seen to be plating anything, too low? Is the idea to use low current density?
- what kind of brass? There are many versions, with different copper/zinc content. Also tried plating on copper circuit board, is that ok?
- what kind of iron? I tried with some cheap iron wire, and not sure if it should be pure iron? What does "white iron" mean?
Note that the heating wire is still intact, but there was something else inside gastight space that caused the pressure to go high enough for black stuff to break. So this is basically a pipe bomb.
How about thermionic emission? I guess it affects, if heating one of the electrodes while other one is cooler? I think there was negative voltage in one of measured experiments, which would make sense if outer pipe has higher temp than inner?
I tried to heat a small piece of metal + had thermometer bolted to same block. So far i do not have anything working, and i'm trying to replicate "lattice energy converter", which allows measuring electricity, which would make it unnecessary to try doing calorimetry with badly working lenr devices that do not create much power.
Got yet another explosion, this time with heating resistor. It was ARGOL 10 ohm 25 watt heat sinked resistor, and the problem was that if i tried to go above 200 celcius, there was "explosion", with one cap of the resistor blown out.
Maybe should try to drill out the center stuff, and use resistor wire, and fill with some non-exploding cement (any suggestions what would be good cement?)
Tried to use nylon tubing in vacuum reactor, and there seems to be slow leak, and started to suspect that nylon might be problematic due to being hygroscopic, and thus leaking water vapor in low pressure environment. Is there some other plastic tube type that would work, since i like the flexibility of plastic compared to metal pipes. Or is nylon ok after initially giving off some vapor?
Well got the nickel carbonate, it was fine green powder, and tried mixing with some vinegar, it takes a few hours while co2 bubbles off, and then you get clear green liquid that is nickel acetate, and that can be used to nickel coat.
Yes, I made order from one pottery firm, only problem with them is that there is no spec about purity, it is just "nickel carbonate".
I live in Finland, and just tried to buy nickel carbonate from Finnish chemistry/laboratory stuff seller, who refused, because they suspect that i do not have proper laboratory and a person that is hired as "chemical security expert". So does this apply to all Europe? Which country do you recommend where i should move to be able to buy simple chemicals like that? Any recommendations where to buy that stuff from the net?
So to avoid explosion the first rule seems to be to avoid red hot temperatures. Then it does not matter if there is some oxygen in the mix. Tried using titanium wire, that absorbed hydrogen nicely. Or could have been just the oxide layer sucking hydrogen? Anyway, hopefully can produce pure hydrogen by first soaking heated titanium wire in "dirty" hydrogen, then using vacuum to suck gas out, and then heating the wire to release pure hydrogen. Works?
One possible reason for explosion was that I had rather long tube connecting hydrogen bubbling part to the jar, so there was possibility of oxygen staying in the cold lower part of the tube, and gradually increasing until contacting the hot upper part and then bang. So if there is just roundish jar with hot wire near bottom creating mixing gas flow, then probably does not explode.
Then maybe should use something else than nickel as base metal, that does not absorb hydrogen? (well maybe all metals do absorb)
What kind of loading ratio can be achieved by loading palladium with deuterium gas at high temp? Sounds odd that loading stops reaction.
Avoiding too high temperatures seems to be working... Did about two weeks run without explosions.
btw, according to Elon Musk "first principles" should be used, but how to apply that to cold fusion? Or what are the fundamental principles of cold fusion?
Maybe should add one more car part: knock sensor 
or some piezo that could estimate max pressure if/when explosion happens
The explosions i saw sounded like hydrogen-oxygen explosion, and were not very powerful, but managed to kick the glass jar lid open and break some weak 3d printed parts. At least one was logged for current and temp once per second, basically there was nothing unusual and then temp dropped due to opened jar.
I read a physics book "Fundamental University Physics: Quantum and Statistical Physics Volume III" and that gave me the idea about thermionic emission. Still have not tried to actually calculate if that is relevant.
There is also stuff about hydrogen, recommend reading that before starting to talk about condensed state of hydrogen.
About filtering water vapor with paper: what prevents the paper from getting wet and then vapor leaks to the other side? Was that measured to work?
