Homebrew PCBs

On Tue, 15 Mar 2005 12:05:40 -0500, uhmgawa <uhmgawa@...> wrote:

>
> Alternatively to avoid intricate pump components having
> to withstand etchant corrosion it would be possible to
> use compressed air to pressurize a container of etchant
> located below board tank level.  This again is not 100%
> duty cycle as the etchant must be allowed to gravity
> backflow to the etchant container when said container
> becomes empty.  Achieving this could be as simple as locating
> a check valve in the backflow line and bleeding off the
> air pressure in the etchant container.  The only thing
> required to automate the process is a float switch in the
> etchant container and a solenoid air valve to alternatively
> pressurize/bleed air to/from the etchant container.


Had the same idea a few days ago. However, will try rotational etcher  
first.
Nozzles need quite a lot of volume.

ST