Easily Soundproof a Stainless Steel Sink

Recently my wife and I replaced the sink in our kitchen with a two bowl stainless steel sink. When we ordered it from our local plumbing shop its description said that it was soundproofed, but when we received the sink we discovered this was stretching the truth a little bit, as the “soundproofing” consisted of four thin rubber rectangles glued to the bottom of each bowl (see the second photo).

Like any good nerd, I searched the Internet for a better solution and found many, including from spray on foam, automotive undercoating, and pickup truck bed liner. All of these solutions required careful masking, followed by a generally messy application of the product - all with mixed results. I am happy to say that the product that I used requires no masking, is easy to apply and works wonderfully - if you tap the inside of our new sink all you will hear is a dull thud.

What I used is 3M Automotive Sound Reduction Mat, a self-adhesive, flexible mat that is designed to reduce road noise and vibration. It is often applied to the inside of the door panels when installing automotive stereo systems, but it also works great on stainless steel sinks. You can find the 3M or equivalent product at most automotive supply stores or from a car stereo shop. The 3M product is a semi-stiff sheet about an eighth-inch thick with a black shiny finish and a diamond pattern. It is self-adhesive, protected by a peel off backing. For me, it came two sheets to a box, which was enough to do one bowl so I purchased two boxes.

Materials

• One or two packages of 3M Auto Sound Reduction Mat or equivalent

Supplies and tools

• Rubbing alcohol

• Cotton balls or cloth rag

• Putty knife

• Heavy duty scissors or utility knife

• This process is much easier if the sink is not installed in your counter top. Ideally, it should be upside down on a solid surface at a comfortable working height.
• Start by unrolling the sound reduction mat and lying it flat to remove its curl.
• If your sink has existing soundproofing you will need to decide whether to remove it or apply the sound reduction mat over the top of the current material.
  • In my case, since the soundproofing consisted of four little rubber squares stuck to each bowl, removing them was the obvious choice. I was able to easily remove them using a putty knife, followed by rubbing alcohol to clean up the residual glue. However, I could imagine sticking the mat to existing sprayed on soundproofing if the spray was thin and fairly level but I have not tried this.

The mat I purchased came two sheets to a box, which was enough to soundproof one bowl for me. Take one of the sheets (do NOT remove the backing that covers the adhesive, yet) and position it over one bowl to get an idea of its best position and how you will need to trim it to fit. If you wish, you can make a paper template and fit that to the bowl, but I just trimmed the sheet a little at a time until it fit correctly. Start with the area that goes around the drain hole and work out from there. Do this for each sheet that you will need. You can see one of my sheets trimmed to fit around the curves of the bowl in the picture.

• When positioning the mat take into account the location of any brackets or mounts that will be used to secure the sink.

Before applying the mat, clean the bottom of the sink one last time with rubbing alcohol to remove anything that might prevent the mat from adhering.

Now you can carefully remove the protective backing and adhere the mats to their places on the bowl or bowls. I removed the backing in sections to keep the mat from accidentally sticking to somewhere I did not want it. If you have a roller, large dowel or screwdriver with a round handle you can firmly roll it over the mat to ensure that the mat is well adhered.

That is it, your newly soundproofed sink is ready for installation. Here is a comparison of the 3M mat to the factory soundproofing. Quite a difference! You can see the finished product in the opening picture.