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Ron Klein
01-23-2017, 8:14 PM
Can a first surface mirror be safely engraved? I want to remove the silver coating to create a sign. I make my own silver coated mirrors with real silver and need to know if the light will bounce back and destroy my laser tube, or worse yet blind myself. I could coat the silver with something if needed but it would be an extra step I would like to avoid if possible.

Bill George
01-23-2017, 8:58 PM
Search brought up pages of answers > https://www.google.com/search?sitesearch=www.sawmillcreek.org&q=engraving+mirrors&submit.x=13&submit.y=8


Most of the new comers questions have been asked many, many times before. This Forum has a wealth of info if you just Search and read.

Bert Kemp
01-23-2017, 10:46 PM
i ENGRAVE THE BACKS OF MIRRORopps all the time never have a problem. I do not know what a first surface mirror is but like I said I engrave the backs a lot. Like Bill said do a search here at the creek, Mirror questions come up all the time.

Kev Williams
01-23-2017, 11:01 PM
If you're putting down your own silver, you may find it tough going for your laser to get thru it. If you put all 100 watts to it, you'll likely break the mirror, I've found it plenty easy to do with just 80 watts...

Aside from that, attempting to engrave silver won't hurt your laser, and as long as your lid is shut, the plex/polycarb window will absorb any stray reflections... unless you're engraving down the side of a cylinder or a beveled edge, either of which can reflect the light off at an angle, reflections are highly unlikely...

Dave Sheldrake
01-23-2017, 11:59 PM
don't even think about hitting real silver with 10,640nm

Kev Williams
01-24-2017, 1:21 AM
So, a little research tells me that silver is bad to hit with a C02 laser, due to possible reflections. Also supposed to be bad is mirror polished stainless, which I tested just to see if reflections would kill my machine. Nothing happened.

Maybe I was lucky, or maybe mirrored SS isn't so bad. But nothing happened.

But another anomaly was brought up in my research...

But first, just want to make note that the tables of my ULS, LS900 and GCC lasers are aluminum. Only my Triumph has a honeycomb table.

So, what was the anomaly? Guess what's the second most reflective metal next to silver?

Aluminum...

oh kay.... ;)

Dave Sheldrake
01-24-2017, 8:39 AM
Aluminum...

It's the melt pool Kev, the stuff is a nightmare even on big co2's that don't have oscillators, before mine were fitted I trashed a few len's cartridges :(

Kev Williams
01-24-2017, 12:19 PM
Well, one thing's for certain, lasers are definitely not 'set it and forget it' ;)...

Tim Bateson
01-24-2017, 6:44 PM
I laser glass, mirrors, chrome, etc... never had an issue. You have to remember a CO2 laser has a VERY short effective range. So by the time it reflects back, I doubt there would be enough power to do anything.