Under counter stainless sink with Formica?

[Will Blick]

I have never done this yet, but am considering it.

I want to use an under mount metal sink, and use a formica top. It's for the shop, so it doesn't have to perfect... just functional. Ideas on how to laminate the cut-out lip of the opening.... I fear basic hot melt laminate will fail after a short exposure period to water. TYIA

[David Giles]

Will,
I'll try anything once, but this doesn't sound good. Water and particle board are an unforgiving combination. That said, how about laminating the bottom as well as the top and attaching the sink with silicone caulk all around? The edge would have to be a smooth cut with no sharp corners so that the laminate would bond without cracking. And I'd put leave a 1/2" laminate lip below the sink so that water would drip off of it rather than run along the underside of the countertop.

[Steve Ash II]

There is a way to do it with a product called Counter Seal but I believe that you have to use their sinks. I'll try to find a url.

[Steve Ash II]

Here ya go...
http://www.counter-seal.com/Home/home/Home

[Will Blick]

Dave, I have considered all what you suggest.... I realize I am bucking the odds here

Steve, great link, but you were right, you have to use their sink. Argggg... I already have the right size sink.

Motorhomes often under mount their sinks with MDF/laminate... they use a rubber gasket-like material (molding?) that goes around the cut-out to cover the exposed MDF. IIRC, you must route a slot around the cut-out, where the rubber molding has an insert, it probably keeps the rubber molding straight and provides added glue-to-rubber area... I never see this product for sale? Any thoughts?

[Pete Brown]

Motor home sinks like that also don't get much use :)

Seriously, I wouldn't try it. Even rubber/plastic edgings offer no real protection. If you are determined, though, you may want to use some sort of epoxy or resin to seal the exposed edges: not pretty, but more reliable than using more laminate.

Finally, keep in mind that the particle board used in these types of countertops doesn't have the strength to hold a sink full of water over time, when being pulled via a couple sink bolts in slots. A regular sink provides a lot more bearing surface. If you want to use undermount, you'll also want to provide support for the sink from under the cabinet via a sink-shaped plywood cutout, or via thick cleats screwed to the cabinet sides.

IMHO, unless you really love this sink, I would ditch the idea. You can get a cheap sink for, well, cheap at the local big box store and save yourself all sorts of work.

Pete

[Jamie Buxton]

I've done something similar, combining an undermount china lavatory sink with formica. The sink gets daily use, and is now close to 15 years old. There have been no leaks and no formica failures. The key was to find an adhesive which will bond to the sink and to the bottom of the formica. Contact cement does not qualify. Some epoxies do. Test the ones you have available, or shop for one which is specified to bond to metal, wood, and plastic. In your case, I'd build a plywood substrate. I'd cut out the sink opening, and use a router to set the top of the sink's mounting flange flush with the plywood. Use contact cement between the plywood and the formica, but use epoxy between the stainless and the formica. Use a bearing-piloted bit to trim the formica in the sink opening.

[Will Blick]

Pete, unfortunately your response makes perfect sense :-(

Yeah, RV sinks get little use, hence why they get away with these methods... I wanted an under-mount sink, for easy clean up, as the surrounding counter top will get wet a lot..... with an under mount sink, its so simple to push the water in the sink, with no lip obstruction.

Then, the weight issue, more work, i was planning to support it from below, but, just another thing that can go wrong...

Since the sink / counter will get lots of water exposure, I better get a new top mount sink. I will search for one, with a very thin lip. Or, as Jamie suggests, maybe they make top mount Stainless sinks where the flange is designed to be flush mounted into the MDF/ply? The BORGs all seem to carry ones with lips that are not flush mount friendly. Flush mount would be the best compromise here.... more searching.....

[Steve Ash II]

Or... nows the time to make your first concrete countertop! Undermounts are a piece of cake!

[Jamie Buxton]

Here's an epoxy which looks like it would do your job...

"3M™ Scotch-Weld™ Epoxy Adhesive. Fast setting, room temperature curing, two-part adhesive bonding a variety of materials such as metals, ceramics, wood and many plastics."

Buy it at http://www.3mestore.com/3m-scotch-weld-epoxy-adhesive.html

[Bill White]

I have never done this yet, but am considering it.

I want to use an under mount metal sink, and use a formica top. It's for the shop, so it doesn't have to perfect... just functional. Ideas on how to laminate the cut-out lip of the opening.... I fear basic hot melt laminate will fail after a short exposure period to water. TYIA


Figure out a way to do this well and the cabinet industry will beat a path to your door. Not to be meant as a smarta$$ answer, but I've never seen it done.
Bill

[Will Blick]

Bill, I hear ya.... It seems there is no flush mount, top mount sinks either.... at least none that I could find... oh well, seems like way more trouble than its worth....

[Howard Acheson]

Going back to your initial post, hot melt glue is waterproof. Have you ever put the glue stick in water? It won't be affected.

The installation guys in our shop used to install lots of counters where the edge met the top (in fact, virtually every one was this way). Never had a problem with water as long as the job was done right.

I think you are letting your imagination get away from you. Use the hot melt and you will be fine.

The process is to put the edging on first, trim flush and then put on the top laminate. That way the laminate covers the laminate to substrate seam and no water can get down there anyway.

[Will Blick]

Howie, it's so nice to see Woodnets greatest asset here also!

Ok, your post and the link below has re invigorated my under-mount concept.

Here is flexible PVC Tee molding I was mentioning above, used to cover the exposed MDF at the cut-out. Since its flexible, I can make the cut-out with rounded corners. Hot glue was brilliant, I use it all the time and yet never considered it for this... your thoughts on this plan?

http://www.outwatercatalogs.com/2007_Master/lg_display.cfm?page_number=14&catalog=070148