Topband: Spark gaps

[Tom W8JI]

Has anyone looked at, or looked for, cheap electric fence gaps??

My system copper pipes near tower legs work great for me on rigid towers, I 
can bend them so they spring away from the tower and then slide an inner 
pipe in or out to set gap distance. I'm thinking of gaps for wire antennas.

Maybe something is good from some other application that is a good bit 
better than a spark plug.