Homebrew PCBs

>
> A constant current source is not essential. Often the voltage can
> be set and the cell ohmic resistance is enough to get reasonable
> consistent current. When experimenting use a electronic power
> supply so you know for sure that your power source is stable. If
> you get into full scale then you should worry about power supply
> requirments.
>
> ......

Thanks a lot, that gave some numbers.
I will see if i can find carbon electrodes.
I was very afraid using them seeing the carbon brush from the motor
coloring the etchant around it dark, but then i had loads of gas and
the brush may have been dusty with carbon dust.
I think i understand the issues you said may happen with titanium.

ST

I have a 1.2 to 1.4 specific gravity hydrometer floating in the etchant,
do you think i can use this to monitor the process?