We recently had a call from a very distressed customer whose wooden toolbox had been hit by an 80 Watt CO2 laser beam, and had caught fire!. After a short conversation it became clear what had happened.
He had a low power Chinese made CO2 laser system, fitted with what gold coated glass mirrors. We’ve seen this before several times, and it can be extremely dangerous. Even in 10 Watt systems, glass mirrors can heat up, the mirror will crack and fall apart, and the laser beam can then pass straight through the mirror aperture. I guess the mirror mount looked like this one that is being sold on Amazon.
It’s sold for CO2 lasers, although they wrongly call it a lens mount. All that stops someone being burnt, or blinded, is a self tapping screw, and a small piece of glass. Of course even 10 Watts is not low power, it will blind instantly, and set many materials alight, including skin.
There doesn’t appear to be any clear rules, regulations or legislation to prevent this happening, other than general “Health & Safety” risk assessment. (please respond if you know differently). AILU is trying to establish a low power laser safety group.
Solid Copper mirrors may cost slightly more than cheap glass based ones, but they are much better suited to, and safer for use with CO2 lasers of any power. Copper mirorrs can never crack, can never allow a beam to pass through them, and can even last longer than the laser. We have customers who have being using the same mirror for more than 15 years.