Had a revelation tonight

[Haywire Haywood]

I build a "half cell" last week to experiment with. It was 3 2.5" +-+ cells in series and I've been running it with my 6v 6amp battery charger about 2 hours a night to see what this "conditioning" thing is all about. Once I forgot it was running and left it going for 6 hours. I had enough sodium hydroxide in it to pull 5a cold and it maxed out at 7a when warm. One thing I've noticed all along is the SS nuts on the end plate were producing. I thought this strange since I had the bolts isolated from all the plates with a plastic sleeve.

Tonight while eating dinner it came to me. The bolts, while isolated from the plates are right there in the bath with everything else and they span the stack from end to end. I had a massive current leak. It was jumping from the first plate to the nut, running the bolt the length of the stack and jumping from the nut on the other end to the last plate. I had a look at my cell and sure enough, the nuts on one end were dark (conditioned) and the OUTSIDE of the plate on the other end (which shouldn't be reacting with anything) was also dark.

I took my cell out of the bath, dried it with a hair dryer, encapsulated the nuts in silicone and tried it again. Lots more production with about the same current draw. Duh.

Ian

[redneckgearhead34]

Thanks friggin genius. I have been seeing that on some of my test cells. I just thought it was normal for some odd reason. I will have to some testing on my own to see how much of a difference it will make and keep it in mind when I make my other cells

[mytoyotasucks]

I always keep my bolts out of the solution.
I knew that they would draw current if they were in the solution.

[Haywire Haywood]

If they're strong enough, I'll be switching to nylon screws instead of sleeved stainless to eliminate this problem.

Ian

[EltonBrandd]

If they're strong enough, I'll be switching to nylon screws instead of sleeved stainless to eliminate this problem.

Ian

Nylon all-thread is definitely strong enough to use. It is expensive locally, $18 a meter. Look on-line and buy a few at once.

[Haywire Haywood]

I couldn't find any locally, expensive or not, couldn't find the stainless all thread either. Had to order it from McMaster-Carr. I suppose I'll be getting the nylon there also.

Ian

[Smith03Jetta]

That's one of the several reasons I don't use bolts or nuts of any kind.

[precaster1@msn.com]

I build a "half cell" last week to experiment with. It was 3 2.5" +-+ cells in series and I've been running it with my 6v 6amp battery charger about 2 hours a night to see what this "conditioning" thing is all about. Once I forgot it was running and left it going for 6 hours. I had enough sodium hydroxide in it to pull 5a cold and it maxed out at 7a when warm. One thing I've noticed all along is the SS nuts on the end plate were producing. I thought this strange since I had the bolts isolated from all the plates with a plastic sleeve.

Tonight while eating dinner it came to me. The bolts, while isolated from the plates are right there in the bath with everything else and they span the stack from end to end. I had a massive current leak. It was jumping from the first plate to the nut, running the bolt the length of the stack and jumping from the nut on the other end to the last plate. I had a look at my cell and sure enough, the nuts on one end were dark (conditioned) and the OUTSIDE of the plate on the other end (which shouldn't be reacting with anything) was also dark.

I took my cell out of the bath, dried it with a hair dryer, encapsulated the nuts in silicone and tried it again. Lots more production with about the same current draw. Duh.

Ian
Could you explain that again in concrete guy terms? A sketch would be best. I don't see how the current will jump and it seems like you would get more production with more amps not less.

[Haywire Haywood]

Electricity is lazy. It follows the easiest road available to it, not the one that makes it work the most. It had a choice to make. Flow through all those plates and the electrolyte between them... or... go through the first plate and instead of jumping the electrolyte to the next plate, jump instead to the exposed nut. Then instead of having to do the obstacle course of the plate stack, it just runs the threaded rod right through the middle and out the other end, thereby avoiding doing any more work than it had to.

More amps = more production IF that amp draw is where you want it. I could put a 1/2" bolt in the water with + on one end and - on the other and could up the amps till it glowed but still get no output from it.

Ian

[precaster1@msn.com]

So your bolt and nut are touching nothing, just there to hold everything together?

[Haywire Haywood]

Yep, they were sleeved in nylon tube with nylon washers to isolate them from the end plates, just the nuts on both ends were exposed. Instead of jumping the gap to the next plate, it jumped the nylon washer to the nut.

Ian