I bought one of those Micro Mark photo etch kits a couple of months ago. The procedure sounded quite daunting, and a slip accompanying it warned of wasting a bit of the materials in the first few attempts as you acquire the skill. So I took it super cautious, real step-by-step.
Yesterday I finished my first sheet of photo etched parts. These were friction shock absorber blades for my scratch 1/8 scale locomobile racer. The blades are not super small, so I thought they'd be a good starting project. I did include some spring star washers that are needed for the shocks also- these are a bit smaller and finer in detail.
I needed 8 blades and two washers. I laid out 12 blades for the blank and five washers. I ended up with all twelve blades usable, but some have some blemishes. I will have no problem selecting the eight best. One of the washers was a bit crudey, but since I only needed two I am delighted.
I did modify one task compared to what the fine, lengthy instruction book says. You are supposed to strip the photo resist off the etched parts with concentrated lye. They include latex gloves for this step (and for the etching in ferric cloride). I didn't like the idea of working with small parts in concentrated lye, and suspected acetone would also strip off the photoresist. I was right- I put the sheet in one of the trays they provide and poured in enough (about a quarter inch) of acetone, and indeed it stripped the resist off fine.
The worst part of the whole project was etching evenly in the ferric cloride bath. They provide an aerator, but that was not quite enough. I still had the resist starting to disappear at one end of the sheet before the other end ate through the etching areas. But the difference was not bad-, I was able to flex the sheet in the area that was not etched all the way through, to seperate the parts from the sheet.
All in all I was delighted with the results. I will now do a few finer detail parts and get on with the project.