I’m in the process of replacing a Kohler cast iron sink that is undermounted to a half inch of solid surface countertop. The sink was set on cleats before the countertop was installed. The screws holding the cleats were pretty inaccessable and I ended up drilling apart the cleats to free up the sink.
The new sink is the HD Pegasus 80% granite 20% resin. It is supposed to have a lifetime warranty from HD. The instructions are very flexible and acknowledge that there are many acceptable ways to install the sink. It is capable of self-rimming, but the customer wanted it undermounted like the original.
I’ve installed it using clear GE silicone II for kitchens and baths. It is supposed to have the best adhesion even on plastics. While it is drying, there are two “3rd hands” holding it up to the countertop. Tommorrow, I will be removing the supports and installing the faucet, airgap and garbage disposer.
The question is, shouldn’t the silicone do a good enough job of attaching the sink to the Ctop or do I absolutely need new cleats? One of the reasons that I didn’t automatically install new cleats is that the front of the cabinet is angled and makes it difficult to install cleats. If you think that I had better install cleats, then how about putting silicone on the cleat and sticking it onto the side of the cabinet (inside) and supporting it until it sets. Because of the clearances, I can’t just screw it onto the inside of the cab. What do you think?
Replies
I would feel better with cleats if this sink has any weight at all.
How about long side panels with the real cleats fastened to them. You fasten the whole cleat frame on the sides, below the bottom of the sink.
Remodeling Contractor just outside the Glass City.
Quittin' Time
Call the fine folks at GE 800-626-2000. They can best answer you. Or check out their website gesilicones .comI do not use the II as an adhesive. Yes it has great bonding qualities but I don't beleive it is a structural adhesive. I had a similar question when I first began to install undermount sinks to Corian and the like. GE introduced me to SCS-1001. The 1001 is used to glaze windows in high-rises and I was told by a GE Sealant and Caulk Specialist that it is ideal for undermount sinks, if you don't want to use cleats.To test it out, I used it and after it dried over the weekend (curing time is 5 days) I stood in the sink. Taa-Daa! Pretty great stuff.Don't know if using this stuff for cleats alone would be sufficient. When/ if you speak to the silicone reps on the phone, besure to ask about any issues with bonding due to the existing silicone residue on the counter underside. Will that affect bond?F
"Or check out their website gesilicones .com"There website is WORTHLESS.
Edited 3/15/2005 10:39 am ET by Bill Hartmann
Ouch!
I'd like to use cleats.
Would a cleat deeper than the sink work? So what if it's 12" deep, it's nice insurance.
Good call Jeff2, actually I ended up using that arrangement yesterday. I picked up a piece of edgebanded melamine, fastened some simpson right angles to it and attached it to the sides of the cabinet. It is clean and matches the cab interior and provides enough support for my piece of mind. I think that if I were doing this with another cast iron sink instead of the composite sink that I used, I would have to use something much beefier.
For anyone finding this thread looking for another solution, there is a sink support for undermount sinks that I have seen at trade shows. It is an adjustable aluminum bracket that attaches to each side of the cabinet at the front and back. Once it is secured to the cabinet, you tighten up some wing nuts to come into contact with the underside of the sink flange. I don't remember what the name of the product is - if I find it later, I will try to come back and add it to this message.
RC