# Do I need to seal a mirror to its frame?



## costgeek (Aug 26, 2016)

Hello all.

I have installed two 30"x30" 1/4"-thick mirrors over my bathroom vanity. I'm going to frame them with rabbeted oak 1"x3"s and want to know if I need to seal the mirrors to their frames with caulk.

The mirrors are already secured with mounts and Loctite mirror glue so the frames do not need to provide support…they are purely cosmetic. The frames are finished on all surfaces with stain and polyurethane and are water-tight. I plan to install the frames with some adhesive and finish nails. The frames sit pretty flush on the mirrors and there are really no visible gaps to speak of. I don't think caulk would add anything cosmetically.

So should I seal the gaps? Could condensation cause me issues even though the frame is water-sealed?

Oh, I also happen to have some Loctite GO2 "crystal clear" glue if that could be used in the gap…

Thanks in advance.

CG


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## splintergroup (Jan 20, 2015)

My only concern would be the caulk being visible when looking at the mirrors edge. I often see this overlooked on mirror frames, the mirror clearly shows what the inside of the frame groove looks like.

Somehow sealing any gap between the mirror and frame might be nice so as to avoid anything getting stuck between there (cleaning paper towel bits, etc).


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## GR8HUNTER (Jun 13, 2016)

> My only concern would be the caulk being visible when looking at the mirrors edge. I often see this overlooked on mirror frames, the mirror clearly shows what the inside of the frame groove looks like.
> 
> Somehow sealing any gap between the mirror and frame might be nice so as to avoid anything getting stuck between there (cleaning paper towel bits, etc).
> 
> - splintergroup


VERY TRUE …make sure you put finish on rabbit


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## costgeek (Aug 26, 2016)

Yeah, the rabbet is stained so the meeting of mirror and frame look nice as is. I was worried about water resting in the bottom gap but good point about debris getting in there too. I wonder if that GO2 adhesive is the answer. It's supposed to dry perfectly clear, I just don't know if I can use it to fill a thin gap.. I guess I could test it…


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## DrDirt (Feb 26, 2008)

I would bed it in the groove with clear silicone, then when it dried, clean the mirror face with a razorblade.

That way nothing sticks out
Drips from spraying the mirror with Windex and gunk doesn't drop in.
But by bedding it, you can avoid as splinter mentions, seeing much from the edge. You can tell, but it will appear the same all the way around.

But in short - - I would caulk it to keep crud out of the rabbet when used for a few years


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## pintodeluxe (Sep 12, 2010)

No. No need to seal in that application. My mirrors are usually supported by the frames, but I have never had to seal between the mirror and frame.

It will create an unnecessary headache.


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## kohalabeeman (Apr 2, 2014)

With time , water may find its way to the mirror's back side where the reflective surface . This happens most often on the lower edge and looks bad . In 'high-end' homes , the owners will talk to no end about how bad a job you did or didn't do , at home though your in control ,so make life easier … Clauk it !


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## Cooler (Feb 3, 2016)

I've made hundreds of mirrors when I was a picture framer. No need to seal the mirror. Just mount a strip around the perimeter to keep it in place.

For smaller mirrors (2 feet by 3 feet or smaller) I simply backed up the mirror with a piece of mat board and drove in framer's points (similar to glaziers points), but they are made from softer steel and can be bent out of the way if required to remove the art. http://cdn.dick-blick.com/items/171/30/17130-0000-2-2ww-m.jpg

Framers points are driven with a point gun that works like a staple gun and is very fast and easy to use:

https://i.ytimg.com/vi/wUDS7gX9Bu8/maxresdefault.jpg

Note: If possible make a very generous rabbet. When you stand to the side with 1/4" rabbet on a mirror you will see the reflection of the cut off of the mirror. A generous rabbet will eliminate that.

I always ended up using pre-made mouldings so I was stuck with he stingy rabbet. But if you are making your own, then shoot for 1/2" if possible.


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## DanK (Feb 5, 2011)

There is a product to seal the back edges of a mirror to prevent moisture from attacking the silvering. Any glass shop that does mirrors will have some. It's a clear spray that dries in a few minutes. Caulking is used to provide a physical bond not for moisture.


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## distrbd (Sep 14, 2011)

I did install a wide mirror in our bathroom 4 years ago but after a year the wife wanted a wooden frame around it so I did exactly what you are describing,I put a nicely fitted frame on it without any caulking or sealant.


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## Cooler (Feb 3, 2016)

Old (antique) mirrors were backed with actual silver and they applied a very thin layer, sometimes unevenly, and you will see dark lines or spots on those mirrors.

Later on they use liquid mercury because it would not tarnish and would apply evenly. But since mercury is toxic they now back mirrors with aluminum.

I've only ever seen darkening of a modern mirror around the cut. So again a wide rabbet will hid this. I never sealed the back of mirrors (but most were not for the bathroom). Some of my mirrors are out there 40+ years and I have heard nothing from any of my old customers about that (I moved about 20 years ago, so the actual available history is about 20 years).


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