DIYbanter - View Single Post

Jon Elson[_3_]

wrote:

I was unhappy with the depth of my brass etching.

I etch brass shim stock with ferric chloride to make stencils for
solder paste for PC boards. My spray etcher has a heater in it, and
I get the etchant up to about 35 - 40 C. The spray system is a typical
pump (Little Giant-style with stainless or maybe titanium impeller and
shaft) and the wand is PVC tubing with holes drilled in it. A fiberglass
window screen is used as a diffuser to break up the jets. I get complete
etch-through of .003" shim stock in about 3 minutes. No electrochemistry
involved here, just etchant and agitation.

Your results look like the effect of no agitation and gas bubble buildup
blocking the electrolyte.

Jon