Homebrew PCBs

Grant,

You could try using one of the Little Giant pumps. I haven't bought 
one of these pumps in years but they used to cost about $25 from WW 
Grainger. Kepro uses this small pump in their etchers. They modify 
the pump by removing the metal impeller and installing one made from 
PVC plastic. There are two pumps in the machine, one for each side. 
The manifold is made from 1/2" CPVC pipe. The pipe has about twenty 
or so small holes drilled to give the spray pattern. A piece of 
plastic window screen hangs between the manifold (spray bar) and the 
part to be etched. This screen is used to disperse the spray pattern 
across the board for even etching. It works pretty good with 1 ounce 
copper taking about 4 minutes to etch with ferric chloride.

Tom