Trying to engrave the back of mirrors

I’ve been trying to engrave the backs of mirrors. I’ve been using some of the 6 pack 12x12 1/8" thick mirrors from Lowe’s. I was curious if you will always get the frosted look on the front when you engrave the back coating off? I ran a material test on one of the mirrors on my 50W OMTech laser. I either don’t get all of the coating off the back or it’s off and get the frosted look. I just didn’t know if that was the only option or if you could get off the backing and have a smooth look. Thanks for the feedback. Here’s my test mirror for reference. I ran the rectangles with a min power of 0%, max power of 70% and then power scales to give me 5%-65%. With a 0.07 line interval and 1 pass each.

Front:

Back:

Because the laser energy has to be applied, it is either going to remove the silvered coating and backing paint and then begin to impact the glass, or it isn’t. Once the glass is hit by the laser, it is fractured microscopically and you have the frosting.

I’ve removed backing paint from a mirror in the past which resulted in the desired object, a front surface mirror, but I used chemical paint remover. A recent attempt also destroyed the silver backing. I suspect the first success was due to higher quality coating, but it’s the type of thing that’s hit or miss.

If your objective is to clear the paint and the silver backing, a chemical stripper may be the only way, but you’ll also want to have careful masking to ensure only the area you want cleared will be affected.

Yeah that’s what I was thinking. I was just wanting to make sure. Thanks!

I like it as it is :crazy_face::grin::grin:

And will steal the idea if you don’t mind, brilliant, thanks

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Haha same I like it. I just wish the color would pop a little more when I paint the exposed part on the back. It shows but it’s not too much through the frosted part. But then again I haven’t tried painting this piece yet just some other tests before that weren’t as much power as some of this test.

:grin:

Will be really interested to see the results please.

We teach teachers STEM subjects to teach to students including laser cutting and engraving. The students will also really like this.

So, you are helping our future artists and engineers, thanks :sunglasses::sunglasses:

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It looks pretty good painted. I just threw on some black spray paint to the back. And Engineer here so always nice to help out the future ones.

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