Another question...
How are the ends of the sheet fastened together?
Trevor,,,, re: washing soda,,,,
I'd go by the activity (action) in the electro, rather than the amp meter, as many times the meter on the chargers are not accurate because the electro does not have the same resistance factors that a batterey with cells has.
When running, after about 15 minutes, I feel/touch my positive and negative clamps from the charger to check for 'heat'... If they are too hot during use, too much soda... if they stay cold, I will tweak the amount of washing soda upwards!
Glad to see you have finally built your electro!! :)