Glass Etching Mini-Project: Next-Level Beer Bottle Cup

I've always been a proponent of "J.F.D.I." and never letting lack of motivation stand in the way of anything. Some of you may know the current medical situation with my family, and it's at times like these that I think it's most important to not let life drag you down and away from doing and making. So today I humbly present to you my (finally) finished beer bottle cup, stylized with a symbol most geeks of my generation should recognize: the Triforce from Legend of Zelda.

In addition to its iconic appearance, the Triforce was actually the perfect design to test because of its geometric simplicity. I purchased a small bottle of glass-etching paste from Amazon without really knowing what I was doing and set to work on one of my bottle-derived cups.To make the stencil for my design, I turned to clear packing tape. The glass-etching paste is highly corrosive but ineffective on plasticized/polymerized surfaces which packing tape, and apparently masking tape, function as. To do this right though, you'll want vinyl contact paper or even "real" stencils from an art store. I wasn't so discerning (read: I'm a cheap, angry engineer) and opted for the solution I already had lying around.Planning my design, I knew I'd want to mask an inverted triangle shape, as well as the outline of the Triforce. To carve a precise triangle, I drew its outline on a piece of paper, put two pieces of tape over that outline. The first layer was sacrificial, it was so I could easily peel off the second layer after I cut out the triangle, since packing tape doesn't easily separate from paper...After taping it onto the bottle cup, I just used straight pieces to complete the Triforce shape. You can just barely see the shape on the bottle in the picture above. By the way, I did a small etching test on a scrap bottle beforehand so I knew the paste (ammonium bifluoride) wouldn't just melt through the tape.I applied the paste to the glass with the only thing I was reasonably sure wouldn't dissolve (a popsicle stick), dabbing it on and letting surface tension draw it into an even coat. The instructions call for a thick coating to be applied, a thin layer won't maintain sufficient concentration to etch the glass. I let it sit for 10 minutes, although the instructions called for 5 minutes. The extra time won't add appreciably to the depth of the etching, but it helps make sure surface impurities like fingerprints are fully penetrated. Ideally you want to have cleaned the glass surface with alcohol or soap. I just used my shirt to wipe it clean.After 10 minutes, give or take, I rinsed the etching paste off in the sink. If you have a ceramic/porcelain sink, you may want to rinse off the paste into a plastic bucket so it's more dilute when you dump it. The paste will apparently eat away the enamel of your sink with repeated use. I have a stainless steel sink so I didn't care.The etching is technically more of a frosting effect. It was hard to see when wet, but I could tell the test had been a success. After drying, it looks like the first picture in this post. Future designs will probably require me to get an exacto knife instead of using scissors and boxcutters to make a stencil/mask, but the etching process itself is wonderfully simple. Another idea I had for an etching project is to make a measuring cup, since I currently don't have one in my kitchen (hard to believe with how much I cook around here).That's it for this post, I'll be putting together a video version of this walk through in the next few weeks (including a new design hopefully) so keep an eye out for that. Until then, happy Making.In case you missed them: