7. Prepare layout for etching - The first attempt of this was to see what would actually happen when I dropped the board into the Ferric Chloride. What came out was some mixed results. the pattern was etched as expected, but there were some unwanted side effects with the process. There was a slight amount of undercutting underneath the Vinyl, which caused a bevel at the edges of the copper traces. there were some spots under the Vinyl Where the FeCl had gone completely underneath the vinyl. Not perfect results, but perhaps still usable with some tinning. The most interesting part was where the Sharpie marker had hit the edges of the Vinyl. There was almost a perfect edge at those spots. (circled in red)
By this point, I had also just discovered that the ValveCaster board I etched was missing a specific component (by the layout creator's design) and probably wouldn't be as useful as I wanted...
However, this was great for an experiment, and I learned a lot from this, but I was ready to try a different tactic...I took another layout for my 2nd attempt, this time for the Pepper Shredder pedal, which is more involved and intricate. Taking another layout:
And converting it into another SVG cutting path:
Cut it out, and applied it, and etched it. I missed the step this time of pressing it with a iron, so the undercutting was more extensive than the first one, with it going almost 1 millimeter under the vinyl.
Not pictured is where I followed another's advice and marked out large sections of the copper board with sharpie, to conserve Ferric Chloride. There was one point where I had used a piece of paper as a straight-edge and marked across the board, between the intended patters, as a separator. Well, there was some ink-crawl underneath the paper and the sharpie ink hit the vinyl again. After wiping it off with Isopropyl Alcohol I discovered on etching that where the Sharpie ink hit the vinyl again, there was almost a perfect edge to the copper traces. Maybe I was on to something here. Time for a 3rd attempt...
I cut out another set of patterns on the Cricut in Vinyl, and applied it to another Copper board. This time, I liberally applied a wet sharpie to all the edges of the vinyl to see what result I would get this time:
I then thoroughly wiped off the entire board with Alcohol to remove the Sharpie ink on the surface. After running it through the etch, I discovered this was the secret to get minimal undercutting, although it presented another issue of its own. Be sure to remove ALL extra sharpie ink off the surface, or you may find yourself with short-circuits (which are easily cut and can be scraped off an Exacto knife)
(click for full-size)