Electrolysis question and discovery

[markba633csi]

If I'm not mistaken you can use sodium bicarbonate instead of sodium carbonate, it just off gasses somewhat more, but they both will make the water conductive enough to work
Mark
ps I don't think you can use table salt because it makes nasty chlorine

 

[RJSakowski]

OK talk about unexpected. As I was doing some cleaning last night I found an old muzzleloader derringer kit I had forgotten about having. As I recall I picked it up for $1 at a flea market some years ago. It had been put together poorly by the PO as it came out of the box and fired it a handful of times, lost interest and didn't clean it before storing it somewhere humid and without temperature control. At the time I cleaned it enough to stop the copious rusting and then promptly forgot about it myself. So when I found it last night I decided to see what I could do to derust it. Disassembled it completely, seriously, 2 screw, 2 pins, 2 springs, brass receiver, 2 spring guides, hammer, trigger and barrel is all there is to it. The barrel had the worst of the rust so it went into the bath first. And soaked overnight. This morning it was rust free, though pitted and discolored so I put the hammer and trigger into the bath. Let them soak a couple of hours and went to check them.

No bubbling going on. Hmmm. Checked the connection to the parts and it looked good. So I went to check the arrow connection and when I touched it, it fell into 2 pieces right at the waterline. When I dunked the part of the arrow still connected to the power back into the bucket the steel parts started fizzing right away. Where it broke was right at the waterline and coincidentally I think right where the arrow had printed on it what it was before. The area surrounding the break was tissue thin and none of the breakdown happened on the outside of the shaft, the painted parts would have made that pretty obvious. And the rest of the arrow that was submerged is as structurally sound as the end that wasn't in the water/washing soda mix.

I am fairly certain the problem with that arrow was a split at the nock end, result of a near Robin Hood shot. I didn't detect any damage elsewhere in the shaft so I am really curious why the damage done by the electrolysis right at the water line only. Very curious so I set it back to brew some more and will see if any breakdown of the carbon happens at the new water line.

So in short, carbon arrows will work and work well for electrolysis but has the unexpected result of dissolving the carbon fiber/epoxy bonds.

Most likely the carbon combines with oxygen from the air at the interface. Also, below the waterline, the reaction continues but it is cooled by ythe liquid. Above the waterline there is no local reaction. But at the waterline you have the combination of reduced heat transfer and the chemical reaction. I'm still surprised that the carbon arrows have that much electrical conductivity.