Is it possible to retro fit a conventional stainless steel kitchen sink with an undermount sink. I have a granite counter top surrounding the 2 sinks. Can this be done and if so, is this a major undertaking? Thank you – Pam

Hello Pam. This might work but it will be very messy and probably not give you the best results. First of all, your top mount sink was most likely caulked around the edge, between the sink lip and the granite surface. When you lift the sink, you will see a caulking stain that will most likely be impossible to remove because it has been there for a long time.

Secondly, a fabricator will have to re-cut and polish the opening to the fit the new undermount sink. A topmount sink cut-out is usually larger than an undermount polished cutout so I doubt you will find a large enough undermount sink that will allow you to do what you want.

If you want to pursue this further, start by measuring the already cut opening in the existing countertop. You might have to get under the sink to measure how and where it was cut. Then look for an undermount sink that is bigger than the opening and still fits within your cabinet size. If you pass these two hurdles, go ahead and pull the sink up to see how bad the caulking stain is.

Hi Tom,

We are thinking about using overmount sink for our granite kitchen countertop for our new home, even though the trend is to use undermount sink. We think that the overmount could be safer after we saw the sealant used in the model home undermount kitchen highly visible. When I wash my foodstuff in my current overmount sink, I often have the water filled to the rim. With this habit of mine applied to the undermount sink probably will wear off the sealant fast and also induce some residue from the sealant to my food. There is some advice out there that overmount sink for granite countertop will make the sink surround difficult to keep clean. My question is: Will sealant wear off faste when constantly immerse in water? Will sealant leech out some toxic when immerse in water. Why overmount difficult to keep the surrounding granite clean as some advice stated? Thank you for your advice. Hope

Hello Hope,

Let me present the pros and cons for both types of sinks and you can at least make a well informed decision.

Undermount sink: It can be debated that an undermount sink allows the granite to present itself better because a bulging sink does not stop the eye from admiring the beautiful natural veining and minerals. The polished sink edge along with faucet holes going through the granite also enhance the high-end upgrade for which you paid so much money. Another benefit is that you can clean your countertop by simply sliding what you are cleaning right into the sink.

Now for the cons of undermount sinks! Undermount sinks do create a maintenance situation at the caulking joint between the sink and the underside of the granite. The degree of maintenance is measured by the method and expertise in which the sink was installed. I have seen the worse and the best. If you go with an undermount porcelain sink, insist that steel ‘sink-spreaders’ are used to hold the sink up. Do not accept cleated wood or notched and screwed wood anchors. These will not last.

Furthermore, the sealant used is traditionally a latex or acrylic-laex caulking. Sometimes 100% silicone is used but because the messy application process of silicone, most installers opt for the water soluble latex caulking. This caulking is sufficient to keep splash water from seeping into your cabinet but it is not suppose to be 100% submerged. Therefore, if you are the type to fill you sink all the way up, don’t use latex caulking.

In fact, I would only recommend a special caulking made by Vulkum Products which specifically states that it is 100% submersible caulking.

Top Mount Sinks: I really don’t like the look but they do have functional purposes. You can get a much bigger sink with a top mount sink because they are not limited in size by the cabinet walls. I feel that is the #1 consideration for going with a top mount sink. If you are going with a soft countertop stone, like marble, the a top mount sink would protect the edge.

Usually you will save $150 to $200 by selecting a top mount cut, instead of a polished edge finish.