Undermount Solid Surface Sinks with Laminate Countertops

A few technical tips on mounting solid-surface sinks under laminate counters. July 26, 2010

Question
I have recently, for the first time installed the product named counter seal ring. Where do you install a 1/2" wide x 3/4" thick Corian rib in the hole cut out in the particle substrate so you can undermount a sink in a laminate countertop? The laminate is adhered to the solid surface ring with a solid surface adhesive. Have any of you guys tried this, and how dependable is it?

Forum Responses
(Laminate and Solid Surfacing Forum)
From contributor R:
Don't adhere the laminate to the ring with solid surface adhesive. You are supposed to use the supplied epoxy that you use to attach the ring to the substrate. They stopped using the solid surface adhesive a couple of years ago and supply epoxy with the rings now. We have been doing these for at least six years. I have lost count of how many we have installed. We have had only one failure, but it was because our installer didn't epoxy the faucet hole cut-out, and the core swelled up from the moisture from the faucet sweating, so it wasn't a ring failure. Now we only use moisture resistant Industrial Board, so that is a non-issue now.


From the original questioner:
I did use the supplied epoxy adhesive that came with the ring but I thought it was the same as the solid surface adhesive. No matter it seems to have gone fine.

From contributor G:
No, that epoxy is not even close to the solid surface adhesive. Glad it worked out for you.

From contributor C:
I have found some very helpful info here over the years, now I'll give some back to the community. I have built well over 300 laminate/undermount sink jobs of various kinds, a few dozen with the Counterseal system. In many cases, to keep my material cost down I mimic the Counterseal system by making my own Corian gasket and buying sinks at wholesale pricing when I have a job of this sort. It is a perfectly viable system if you follow the instructions to the letter and use the supplied adhesive. Solid surface adhesive is not the best choice due to its brittleness.

Remember, your laminate countertop is going to move with changes in temp and humidity. The epoxy supplied with the counterseal kit retains a bit of flex. This is the key to the whole thing staying water tight for years. There is a new sink on the market for this application that basically renders the Counterseal system obsolete. The same people that make the Karran acrylic sinks for this application have a new stainless sink called the "Edge" that eliminates the Corian gasket in the Counterseal system. It costs half of what the counterseal system costs and is a simpler, more reliable system. The "Edge" people say to use solid surface adhesive in their process but we use the Loctite product that Counterseal uses. We get it on line from any number of distributors. Undermount sinks in a laminate countertop are the future of the laminate countertop biz.

I grabbed onto this idea very early on for my business and it has become the cornerstone of what we do. Nearly every job we build for residential use at this point has an undermount. Check out our unique system featuring quartz sinks. Anyone interested in undermount sinks in laminate countertops should take a look at our website.