How to protect the back of a mirror from sunlight?


I have a vintage frameless mirror mounted in a bathroom window. Previous owner protected the mirror's backing paint by covering it with tinfoil which is now coming off and creating a mess. Don't wish to add a wood backing so I was wondering if there is a paint I can apply over the backing paint that will protect it from sunlight?

  13 answers
  • GrandmasHouseDIY GrandmasHouseDIY on Sep 16, 2021

    Hi Dwain! Honestly I think any kind of paint would work for this. Black Rustoleum would be what I would use because its oil based and tends to be a lot more durable.

  • Cheryl A Cheryl A on Sep 16, 2021

    there are spray paints for mirrors and glass that would work for you just look in your local Home Depot type store

  • Betsy Betsy on Sep 16, 2021

    Hi Dwain: Choose a glass paints that cure without heat. Acrylic and water-based enamel craft paints stick to the slick surface of glass and are quick to dry and have a durable finish. Keep in mind that the darker the paint, the more heat it will absorb, so a white or light colour may be best. Be sure to clean the surface completely, as preparation is the key to a good job.

    Good luck

  • Dwain Medlin Dwain Medlin on Sep 16, 2021

    Thank you all for your replies and helpful advice.

  • Mogie Mogie on Sep 16, 2021

    You could resilver the back. It isn't cheap but if this mirror has value to you look into this.

    • Dwain Medlin Dwain Medlin on Sep 16, 2021

      There is no need to resilver. The mirror front and back is in very good shape. I am just trying to keep it that way. The back paint is exposed to direct sunlight without some type of covering. Previous owner taped tinfoil to back to block sun. While the tinfoil worked for years it has started coming off. I would like to use paint instead but am concerned with damaging the back paint and silver backing if I use the wrong paint. My local paint store was unable to help.

  • Redcatcec Redcatcec on Sep 16, 2021

    You can also find the glass paints that cure without heat at Amazon.

  • Em Em on Sep 17, 2021

    Not sure why you don't want to add wood. Best protection for sun. A thin piece of luan and 4 glass clips would not be heavy and give you 100% protection. I would be concerned that a spray paint may be a problem for the silvering on the back of the mirror.

    • Dwain Medlin Dwain Medlin on Sep 17, 2021

      Considered 1/8" luan and decided against it for a number of reasons. Mirror is frameless and basically floating in a window. Four clips would not stop thin plywood from warping and don't want to add a frame. Glue would create even more problems.

  • Kmdreamer Kmdreamer on Sep 19, 2021

    Use like a brown paper bag to cover it just tape it on or glue it

  • Dwain Medlin Dwain Medlin on Sep 19, 2021

    Thanks for the suggestion but number of problems with that. Brown paper bag wouldn't last long exposed to strong southern sunlight. Also, point of covering back of mirror is to protect it from absorbing heat from sunlight which brown paper would intensify. If I decide to cover it with taped on covering, original owner's idea of using tinfoil would be better. Thank you again.

  • Dwain Medlin Dwain Medlin on Sep 19, 2021

    I understand that there is a 2 step epoxy backing paint out there called Grincoat. I think the topcoat of that product would work but am unable to find anyone who sell it. Does anyone out there know where I can buy Grincoat or a similar product?

  • Maura White Maura White on Sep 19, 2021

    I would use a spray paint that can be used on mirrors or glass to protect it!

  • This is a very specific application. I would definitely ask at either a) an antique store since their dealers may have some advice for you or b) at a paint store, a specialty one, not Home Depot. They have more knowledge when it come to the specifics.

  • Deb K Deb K on Oct 07, 2021

    Hi Dwain, you can buy rustoleum mirror finish and spray the back with it,