The undermount sink is an appealing alternative to traditional drop-in sinks, both in terms of aesthetics and functionality. While drop-in sinks with potentially bacteria-catching rims are necessary evils in many kitchens today, more often than not, an undermount sink is preferable. Undermount sinks come in a variety of materials and styles and now can even be installed with laminate countertops. One of the most functional material combinations when it comes to sinks and countertops is the solid surface sink undermounted to a solid surface countertop. Why? The results are seamless installations in many patterns, colors and material thicknesses.
What's the appeal of this integral undermount combination? The sinks and countertops are sleek to look at, offer the convenience of being able to wipe countertops directly into the sink without hindrance and are generally more hygienic than drop-in sinks. I am sure most people can appreciate just how unsanitary the rim of a drop-in sink can become after years of use.
THE MANUFACTURING PROCESS
In a discussion of undermount solid surface sinks, one would be remiss to assume all solid surface sinks are made equal. Actually, they can be quite different. There are numerous types of manufacturing techniques when it comes to solid surface sinks, such as poured or cast and thermoformed or vacuum-molded.
Poured or cast sinks — Poured or cast manufacturing refers to when a male and female mold, separated by about ½ in., are filled with a liquid resin and left to set up over time. The molds are then split apart and the sink is removed. This process can be expensive because it takes more time and requires many identical and expensive molds. But it does create a sink with a heavy weight as well as uniform thickness. Consumers equate heavy with strong and good quality; however, some argue that poured sinks can suffer from cracking when exposed to rapid changes in temperature. Poured sinks have the advantage of tighter corners and radii than vacuum forming, though, resulting in more style definition in some cases.
Thermoformed or vacuum-molded sinks — Thermoformed and vacuum-formed sinks involve taking a flat sheet of material, heating it in an oven until it is flexible, then placing it over a mold and using a vacuum to suck the air out from between the mold and the sheet of material, drawing the material into the shape of the sink mold. This type of sink has the disadvantage of being thinner and lighter, leading consumers to think the sink may be of lesser quality; however, these sinks are usually reinforced with fiberglass on the back side, which can actually make them stronger than some poured sinks. This type of sink can be strong and durable though because it will generally not suffer from thermal cracking problems.
Chemical make-up also varies greatly between brands of sinks. Just as with a solid surface countertop, the sink material may be made with either polyester or acrylic resin with greatly varying ratios of resin, which can also affect both the performance and price of a solid surface sink.
Acrylic-based material is generally harder, more impact-resistant and less brittle than polyester. Acrylic also has greater thermoformability, meaning it can be formed and shaped with heat more easily than polyester. Polyester, on the other hand, is more chemical-resistant and can also achieve a higher polish than acrylic and offers a greater ability for achieving a translucent effect. Polyester costs less than acrylic so, in general, polyester-based products can be more inexpensive than acrylic-based products.
So, is one sink better than another or are they all pretty much the same? Absolutely there are some sinks that out-perform others. When it comes to permanently bonding a solid surface sink to your countertop, a little research and investigation is always worthwhile. So, what is a great sink? It is one that is completely nonporous. It should be a breeze to clean and not be prone to staining. High-quality sinks should be resistant to heat and thermal shock. They should also be easy to fabricate. Educating yourself on sinks is simple. Call your fellow fabricators, read industry message boards, read industry publications or go to training classes. The information is out there as to what sinks are preferred by fabricators. And more importantly, which sinks they don't.