Re: water spark gaps

["Jason Johnson" <hvjjohnson13-at-xxxxxxxxxxx> (by way of Terry Fritz <twftesla-at-xxxxxxxxxx>)]

----- Original Message -----
From: Tesla list <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Wednesday, November 29, 2000 10:01 AM
Subject: Re: water spark gaps


> Original poster: "Jochen Kronjaeger" <Kronjaeg-at-Stud-Mailer.Uni-Marburg.DE>
>
>
> > Has anyone ever experimented with water spark gaps?  If so, did you run
> > into any big problems?
>
> I tried this recently, though not systematically. I simply submerged my
> multiple copper tube gap in a bucket of tap water. This turned out to
> be far too conductive, i.e. shortet my OBITs without charging the cap.
>
> Deionized water will be better, but considering the small gap distances I
> doubt it will work well. Also, the water will propably degrade rapidly.
>
> I experienced another strange problem when drawing an arc between a copper
> electrode and a water surface. Sometimes, there was something like a small
> explosion, not really violent, but quite a shock.

I experienced this same problem while playing with two MOTs and a pop can of
water. I used the pop can (with top cut off) and the water as one electrode,
and a 12 guage solid copper wire as the other, dangling about an inch above
the water. I would start an arc at the surface of the water and pull the
copper wire back. The copper wire melted into a big ball at one end and
would fall into the water flash-boiling it and sending hot water droplets
all over. Twice when  this happened a very large molten copper ball
(1/8-1/4" dia.) fell into the water and made it all the way to the bottom
without cooling all the way. When it hit the bottom (aluminum pop can) the
water exploded, sending all the water in the can up in a foot tall column of
hot water. The water landed all over me and my large variac setting under
the bench. This happened twice and each time it happened I couldn't
reproduce it whenever I wanted.

Jason Johnson

 This might be due to
> electrolysis (hydrogen+oxygen production), but I somewhat doubt this as
> there was no reason for hydrogen to accumulate. Anyway, let this be a
> warning that unexpected and possibly dangerous effects might occur with
> under water gaps.
>
>   Jochen
>
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