Best adhesive for mounting mirrors

[Rick Taylor]

I am going to be turning several hand mirrors with handles to be given to family members as gifts. I saw some turned by John Lucas earlier and was inspired to turn some on my own. Mine will be very simple unlike the beautiful ones John creates. I expect to spend as much time as necessary making them as well as I can. I want them to be able to stand the test of time. I intend to purchase quality mirrors but am concerned about what method and adhesive to use to mount the mirror after the turning is completed. I do not want the mirror backing to be adversely affected by the adhesive. What type of mounting have you used in the past and how has it held up over time?
Thanks in advance,
Rick Taylor

 

[Ian Thorn]

If you are buying your mirrors from a glass company use what they recommend, I would use i silicon type glass glue or a flexible contact adhesive and leave a small gap at the edge for wood movement.
Ian

 

[john lucas]

I use clear silicone caulking. It's looks and smells like the stuff they sell in the glass shop but is about 1/4th the cost. Of course you do need a caulking gun. Sometimes you can buy smaller tubes in the glue and paint section of your hardware.
I have tried other things over the years and had failures so I would advise sticking with the caulking or mirror glue(same thing)

 

[Rick Taylor]

Thanks for the quick reply John. I will get some clear silicone and give it a try.
Rick Taylor

 

[Bill Boehme]

Here are a couple:

• Liquid Nails LN-930 Mirror Adhesive
• Loctite PL-520 Mirror Adhesive

Some silicone adhesives can react with the aluminized or silvered coating on mirrors. Also, some adhesives may get too hard over time and cause the coating to pull away from the glass.

 

[Wayne Spence]

Mirrors

Many years ago I made hand mirrors out of walnut and cherry. The one for my wife cracked after about 4 months. I notified those who had purchased the others and there were no problems. I never heard any more from the purchasers. I attributed the cracking to wood movement and epoxy used for mounting the mirrors . The fit between the wood frame and the mirror probably left no room for expansion or contraction. From my bad experience I would stick to what has been recommended by Lucas,

 

[john lucas]

First of all I allow for wood movement. I undercut the mirror opening so the glass will go in but the bottom of the groove is cut larger using my Thompson detail gouge. Here's a video I made to show the important details of making a hand mirror last.
https://www.youtube.com/watch?v=jgVdMOrGgXU

 

[stu senator]

Years ago I had to mount a 1 meter dia ceramic ring to an aluminum ring and be vacuum tight and not have it fail under normal (50 to 150 degree F) temperature change.

I did this by using a flexible epoxy and maintained a gap of .01" between the components. The epoxy was in shear stress and its load rating and that of the aluminum and ceramic rings was not exceeded so the joint held.

In this case you have a wood that is subject to moisture and temperature changes in size as well as limited strength and glass that does not move much in normal room temperature changes.

A flexible adhesive that has adequate shear strength and a uniform gap between the wood and glass would work. The gap may be maintained with shims. The gap must be adequate so that the shear strength of the wood, glass or adhesive is not exceeded in the temperature and humidity travels of the shop, transport, storage or use of the item.

I can not give a number as it will vary with application, only general rules.

Stu

 

[Bill Boehme]

.... The gap may be maintained with shims. The gap must be adequate so that the shear strength of the wood, glass or adhesive is not exceeded in the temperature and humidity travels of the shop, transport, storage or use of the item....

That makes a lot of sense. If the adhesive layer is too thin then any benefit of its flexibility would be lost.