We have a niece getting married on the 21st. I was asked to make a basic welcome sign for the big event. As usual, I got a bit carried away. I had planned to make a wood frame with a mirror with the info engraved into the back of the mirror & painted black like I usually do.
I decided to get creative & see if I could back light the text with Led’s. It worked out really well. Not knowing what the lighting will be like at the church & reception, I was concerned that it would be bright enough. I had a strip of side mounted led’s & 3D printed mounts for them. They allowed me to double up the led’s for each line of text. The photo in the back yard ensures that lighting won’t be an issue.
I built an 8 cell AA battery pack into it along with a power jack for a wall adapter. I can’t wait to see the looks on their faces when we drop it off tomorrow!
That looks great! So, the LEDs illuminate through the 3D printed bracket (the bracket acts like a diffuser) or does the bracket have holes that align with the LEDs?
The mirror is positioned in front of the led’s about an inch away. I put white packing tape on the back of the glass to diffuse the light. I thought after the fact that I could have used more laser power to fracture the glass which leaves it looking frosted. Next time! Engraving mirrors & leaving the glass clear requires low power. I used 10.9% power with the Laser Tree K60 laser set to 20w. I usually paint the back of the mirrors different colors, & the colors are more vivid if the glass is clear.
I’ve experimented with techniques to etch away the mirror silvering on the back. What worked best for me was covering the back with tape, then laser etching with just enough power to nearly get through the tape. I followed up with an application of muratic acid (concrete cleaner) that easily removed the mirror backing while the untouched tape acted as a masking film.
Results worked great, clear, unetched glass and sharp lines with the mirror silver backing.
After engraving, there’s a little dust residue stuck to the clear glass. A few passes with fine steel wool takes it off easily.
The next time I plan to back light, I plan to turn up the power a bit so that it leaves the glass frosted. That will provide an even coating to diffuse the light.
