How can I easily fix my bathroom medicine cabinet mirror?

June 5, 2019 12:34 PM

My medicine cabinet's mirror has developed these big black spots behind the glass. Ugly. I can't easily replace the medicine cabinet itself. Is there a way to fix this situation without replacing the cabinet?
posted by storybored to Home & Garden (8 answers total)

This is usually because the 'silvering' (coating that makes glass into a mirror) is going bad. It's made from actual silver, and when the varnish covering it wears off, the silver tarnishes, leaving black spots/streaks.
The only cure is to either replace the mirror, or have it re-silvered. Re-silvering is expensive and very hard to find. The only place that did it in the Seattle area closed almost five years ago. So replacing the glass (a glass/mirror shop might be able to help you out) is your best shot. It *could* be as much (or more) to do that than to replace the cabinet, though. Good luck!
posted by dbmcd at 12:41 PM on June 5, 2019 [2 favorites]

If the design of the cabinet permits it, it might be easiest to stick a new mirror on top of the old one... one that fits exactly. Or even one that's slightly smaller and leaves an equally wide border of the old mirror visible on all sides, provided that none of the spots are in that border.
posted by Too-Ticky at 1:06 PM on June 5, 2019 [2 favorites]

There is spray paint that does a cheapo version of (re)silvering. I don't think it claims to make your mirror as good as new but if you're just looking to improve the appearance of spots around the edges it might do the trick.
posted by stefanie at 1:20 PM on June 5, 2019

Depending on your particular cabinet, it may be possible to disassemble it and replace the mirror only. If you can take some photos of the cabinet showing how the door/mirror are connected and post them somewhere (imgur or something similar), someone here might be able to give you ideas on if/how this could be done.
posted by yuwtze at 1:24 PM on June 5, 2019

Might you have a model name/number of your cabinet? This could help with finding a part number for a replacement door — it can be easy to replace a door, even if the cabinet would be difficult to swap out.
posted by They sucked his brains out! at 2:12 PM on June 5, 2019 [1 favorite]

One of our bathroom cabinets developed these spots when the spray cleaning solution we used on the mirror ran around the edge and soaked into the back.

Our mirrors (3) also serve as the doors and have a steel disc stuck to the back of the mirror to mate with the magnetic catch. The solution also dissolved the adhesive and pulled off a round patch of the silvering. When we prep for selling I plan to take out the mirror panels and have a glass shop cut three new ones.

If I have this type of mirror/door in the future I'll try some clear spray to seal the silvered back.
posted by tronec at 3:45 PM on June 5, 2019 [1 favorite]

Response by poster: Some great ideas here thanks so much to everyone.

@They - the door is riveted to the mirror, so is pretty hard to remove.
@dbmcd - yeah, resilvering is probably going to be more dough

@Too-Ticky - I think I'll pursue that! Another idea it sparked: The black patches are around the edges, so I was thinking of making a new frame and gluing that to the mirror, where the frame will cover the patches.
posted by storybored at 5:45 PM on June 5, 2019 [2 favorites]

Response by poster: Followup: I ended up doing much simpler, and easier. cheap too! I ran across a company called dc-fix that makes self-adhesive metallic film. I bought a roll of it (silver colored to match the existing frame color) then I just put a 4 cm tape border around the mirror. (i.e. a "frame" of tape).
It is not super perfect or beautiful but way better than the black stained thing I had before!
posted by storybored at 6:52 PM on June 14, 2019