MacGregorSailors.com

I think I want to mount a tv on the mirror - can it be drilled through?

as there are several mirrored pieces in the cabin that have holes, i would have to say yes. The mirror, as far as I know, is not a glass mirror, so it should be OK

If you mean the big mirror on the bulkhead, I've drilled several holes in it to mount galley shelves, no problem. (See mod here for a similar example.) I'm certain it is some kind of plastic.

That is where BWY put our TV. It is ok there but when sailing put a bunjee around it so it doesn't swing around, ours is on a swing arm, it is good for loading DVD's.

The mirrors are made of acrylic sheet. It can be drilled with standard twist drills, but you must go thought the material very slowly, especially when breaking through the back surface. To make nice clean holes with no cracking, grind the drill bit cutting edges flat, so they scrape the acrylic, rather than cut into it. It also helps to grind a steeper tip angle on the bit - at least 90 degrees, and 60 degrees works even better. If you don't have a grinding wheel, Plastic supply houses (like Tap Plastics here in California) sell bits ground like this for drilling plastic sheet. Drill your holes a little larger than your fastener to reduce the possibility of stress cracks spreadinmg out from the inside wall of the hole. Don't over tighten the fasteners, again to reduce the possibility for stress fracturing over time.