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How To Remove Mastic From A Mirror [3 Methods To Try]

Mirror mastic is often used to attach frameless mirrors on walls. It is a powerful adhesive that usually leaves traces on the surface. Have you removed a mirror from the wall and want to clean the mastic left?

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Are you searching for ways to do so? If you are, then you’ve come to the right place. We have done our research to give you the methods and steps to remove mastic from a mirror.

There are different ways to remove mastic to clean the wall or the mirror. Along with other tools, choose one of these methods to get rid of the adhesive from your mirrors.

  1. Non-chemical method
  2. Applying heat
  3. Solvent method

Throughout the post, we will provide detailed steps for each method. You will also learn more about mastics to help you identify which way is more suitable. Continue reading to get more information on this topic.

The Old mirror restoration. Antique antique mirror. Restoration and cleaning of the old mirror., How To Remove Mastic From A Mirror [3 Methods To Try]

What Is Mastic?

Top of homemade bright mousse cake with mirror glaze.

Mastic is an adhesive used to safely and easily attach mirrors on walls. This is used to avoid damaging the mirror’s lining during installation.

Mirror mastic is also designed not to damage the back of the mirror when removed.

However, if there is a need to take the mirror out and move it somewhere else, the mastic residue may be difficult and tedious to remove.

How Do You Remove Mastic From A Mirror?

Most of the time, when you are upgrading the mirror or trying to move it to a different location, you’ll find that you’ll have to remove the old mastic or adhesive, not only from the wall but behind the mirror too.

In these cases, you can try three different methods:

1. The Non-Chemical Method

First, try this method before resorting to using solvents. This is easier since you only use readily available cleaners in your house.

You’ll need hot water, a putty knife, a razor scraper, a heat gun, an iron or air dryer, and an old newspaper or brown bag.

Pour Hot Water Over The Mastic

Hot water in a glass.

Some mastic is water soluble, and this method will only work for those kinds. Before scraping the mastic, soak it in hot water. Adding vinegar to the hot water will make a more potent solution.

Moreover, this solution will make the mastic soft, and you can scrape it off easily after an hour of soaking.

Scrape Off The Mastic

Hand with putty knife repair damaged wall

After soaking in hot water, you will notice that the mastic will become loose. This is the time to scrape it off. Using a putty knife or a chisel, remove the mastic while it is still wet.

Lastly, wipe off the surface. You may repeat the process if you still see traces of the adhesive. You can also scrape off the remaining adhesive with a razor blade or scraper.

Click here to see this razor scraper on Amazon

2. Heat The Mastic

Another way of removing mastic is by applying heat.  This is because mastics contain linseed oil that becomes soft when treated with heat. For this method, you may use an iron, a heating gun, or a hair dryer.

Bear in mind that when applying heat using a heating gun, keep it at least 18 inches away from the mirror’s surface and make sure not to concentrate the heat in one area. This will keep the mirror from breaking.

If you don’t have a heating gun, use a hair dryer, and keep it a few inches away from the mirror. Place a rug or an old newspaper over the mastic, then heat the area.  Use the paper or rug to wipe the melted mastic.

If you don’t have a heating gun or a hair dryer, you can use an iron to melt the mastic. After placing a newspaper or brown bag on top of the mastic to be removed, run the iron over the covered area.

Run the iron as if you are ironing clothes; this way, the mirror will not be overheated and won't break. Use the newspaper to clean the melted mastic.

Use a wet scrubbing pad with soap to remove the residue of the adhesive.

3. The Solvent Method

A hand of a painter holding on a piece of cloth, soaked with thinner, removing sticky rough glue and tape remain on the old concrete wall

Some mastics can’t be dissolved by hot water or heating. In this case, a solvent needs to be used. For this job, you’ll need an adhesive remover, a putty knife, a razor scraper, a paintbrush, and a rug.

When doing this method, make sure that you wear safety gear like a face mask, a pair of gloves, or goggles.

The solvent method is time-consuming as it involves applying mastic remover, waiting for it to react, surface agitation, additional applications, and re-scraping.

Spot Test

Before application, test the product first. Mirror mastic is usually applied to different areas of the mirror. You can put a solvent or adhesive remover in a small spot to see if it’ll damage the mirror’s surface.

Apply the product per the label’s instructions to maximize it.

Apply The Solvent

Use a paintbrush to apply the solvent over the mastic to be removed. Add more solvent to the edges to soak it. Let the remover sit for a couple of minutes.

Soaking the mastic will break the bond; thus, it’ll be easier to lift later.

See this mastic remover on Amazon.

Lift The Adhesive Off

Now that you have left the solvent to soak the mastic, it’s time to lift it. Add a bit more solvent to the edge of the mastic where you’ll insert the putty knife. This will lubricate the blade and further break the bond of the mastic.

Next, make a rocking back-and-forth motion while prying the adhesive. This will ensure that the mirror won’t be scratched or damaged. Forcing the putty knife into the adhesive may break the mirror. Add more solvent or mastic remover as necessary.

After this step, you’ll find the bigger portion of the adhesive gone, but some residue may still be left.

Scrape The Residue

Next, grab a razor scraper. Run the razor scraper to remove the tiny bits of the adhesive left.  Finally, after you've removed the residue, get a rug or a scrubbing pad to wipe the traces of the solvent off.

Now that you have removed the mastic, the back of the mirror will be flat and ready to be reinstalled.

How Do You Remove Mastic From A Wall?

Although most mastics are designed not to damage the wall, you must remove them carefully.

You can do the same process discussed in the previous section to remove the remaining mastic from the wall.  If you are going to use solvents, make sure that the room is ventilated.

Check the label to see if the product is appropriate for the surface. There are different mastic removers for wood, concrete, and other surfaces.

Depending on how much residue is left on the wall, other solvents like acetone or rubbing alcohol may also work.  In some wall types, like drywall, a repair may be needed to mask the surface where the mirror was removed.

It is important to note that you should not overuse mastic remover, especially if you intend to reinstall an upgraded mirror or frame in the same area. This may affect the surface and make it difficult to bond something in the future.

To Wrap Up

Removing mastic or any adhesive comes with home renovations that involve uninstalling and reinstalling mirrors. Doing so may be difficult and tedious, but it is not impossible.

To properly remove mastic from the mirror and the wall, prepare tools like a putty knife, razor scraper, heating gun, hot water with vinegar, and solvent or mastic remover.

You can use different methods, such as heating, non-chemical, and solvent, to clean the mastic off the mirror. Ultimately, whichever way you choose, this will help you eliminate that mastic from your mirror and wall.

If you found this post helpful, be sure to check out these other articles:

How To Hang A Frameless Mirror [2 Different Techniques]

Can You Use Mastic In A Shower?