I've just had a bespoke mirrored bathroom cabinet installed. The mirrors have had holes drilled for the knobs, and one of the holes has a white mark around it and generally doesn't look very clean. The mark is visible even when the knobs are in place.
The cabinet maker tells me "such a white mark around the cut out in the mirror is normal. It's very difficult to cut through the mirror with a very clean cut".
Is my cabinet maker correct, or should I ask for a new mirror?
See pictures:
Best Answer
I used to work for a company that built machines that drilled these holes (though we did it in much larger pieces, usually 3/4" to 2" thickness). It's not a hard process, it's slightly expensive, but it's doable. The process is basically as follows:
In the situation where vibration cannot be controlled, and you don't have an upper and lower bit, the manufacturer would typically use an ultra-low RPM (like, 20-30 RPM) which avoids the vibration. This takes longer to cut a hole, but avoids problems.
With ultra-thin material (1/8"-1/4") we would use a direct water-jet, we would literally push water at 60,000 PSI and blow a hole straight through the glass. This is done by backing the glass with a solid (usually metal) surface with a hole for the jet-stream.
You should end up with a clean-cut hole, and no scarring or scoring - minimal fracturing. We used to build these machines, and this type of scoring is very unusual and indicates a faulty machining process. Your cabinet maker likely has one of these machines quite possibly from us or a different company.
This is a defect (it actually looks like the mirror wasn't adequately cooled, so it fractured). It's plain-and-simple, this is a manufacturing defect, and you can probably convince them to send you a new one.
However, I would avoid that altogether.
While this may be unsightly right now, here's how I would fix it (usually for less than $2.00 at a nearby hardware or crafts store):
If done right, you should be able to eliminate the defect area visibility entirely, and you should end up with a visually pleasing result. Depending on the theme of your bathroom, you may opt to get a larger OD on the washer and use an "accent colour" ('hot rod red', for example) to make it "pop" and get a more unique look.