We All Have To Learn Somehow.
I will now try to detail my mistakes, and what I'd do differently.
First & foremost: I left it to etch for too long. Most of the sources I read on this particular method & mix for etching generally encouraged multiple runs in the etchant, at 5 to 15 minutes each. This was more for consistency, and especially for those etching artistic designs rather than circuit boards.
It took me soo long to dig out the resist that I wanted to do this in one shot, if possible! I don't think it needed 45 minutes, even spread across several dips. But reports from others using similar recipes were yielding inconsistent results based on standard timing intervals (likely due to not-fresh ingredients). My hope is that with future attempts, proficiency & efficiency will increase, making the thought of successive applications of resist less dreadful!
The initial resist was a solid orange because, of the four colors given to me by SWMBO, it blended with the metal tone of the razor the least. Two had glitter, which I suspected would be a bad idea for a resist fue to the likelihood of it being metallic in nature. The secondary coat I applied to fix some of my boo-boo's was one of these glittery shades. It seems this resisted the acid less than the orange color. Lesson learned.
Another hypothesis: my self taught technique for digging out the resist was flawed in the final stages. The tolerances I was trying to correct to for finishing the lines were such that I was afraid trying to even chip it away minutely with my needle (tip refined on a 15k Sharpton) would remove too much material. So I figured out the polish was just malleable enough to push it aside slightly (very carefully!). What I couldn't see: this caused the resist to lift & separate from the razor, expediting the undercutting effect. another lesson learned: don't push the polish!
The container I used was effective for repurposed trash, but could have been better. I poured the etchant into an empty 20 oz. bottle (cleaned), and it came to just under 20 oz. Food for thought. Anyway, ideally, I'd like some sort of container that can be sealed (or at least closed tightly). Good dimension would be around 2"x7"x3", or maybe 3"x8"x3" just for added wiggle room. I can MaCGyver a harness for suspension, and a hole for the air lines.
Well, that's about all I can think of right now. Despite how thorough I've been, I feel like I'm leaving something out:confused::shrug:.
If y'all have any questions, please feel free to ask! Got my trainee again tomorrow :y:nj:beer2:.