My bathroom has a Corian sink that uses a tube for the overflow drain. Unlike most overflow drains, this one is not molded into the sink itself. The sink is 20 years old. The box at the end of the tube appears to have been glued onto the under side of the sink, but now the glue is old and it has come off.

Should I remove the glue from the old box, or buy a new box? I can remove the box from the tube, it is just held there with friction and some ridges. Do they sell the boxes? If not, how should I remove the old glue?

When re-attaching it, what adhesive should I use? I'm thinking of using clear silicone. Is that a good choice?

  • Here is the best resource that I have found so far: askmehelpdesk.com/plumbing/… There is some disagreement on what type of glue to use, and nobody has addressed removing old glue or getting a replacement box. – Stephen Ostermiller Jan 5 '17 at 19:30

I ended up using a utility knife to cut off the old glue then I washed the part. I also cleaned the underside of the sink and sanded old glue off. It turned out pretty well:

I used clear silicone (applied with a caulking gun) as the adhesive:

Because the silicone doesn't adhere very strongly, I followed the advice to find a way to put pressure on it. I cut a wedge that can go between the overflow and the cabinet:

This overflow drain is in the front of my sink, although I have another similar sink where the overflow is in the back. In this case because the overflow is in the front, I figured out how to remove the front panel of the cabinet to make access easier. Here it is installed with the silicone and the wedge:

I used a screw from the outside of the cabinet to hold the wedge in place. The front of the cabinet ends up covering up the screw, so it isn't even visible once everything is back together.

I then added some more silicone around the outside, connected the tube, and put the front of the cabinet back.

So far it is working for minor overflow problems. I can splash water down there.

I tried filling up the sink up above the overflow and it isn't perfect in that case. The overflow drain doesn't take water as fast as the faucet can put it in the sink, so eventually the sink will overflow. I didn't glue the top of the overflow because it looks like it isn't meant to be glued there. Because the water level can get high, that means that water eventually comes out the top of the overflow into the inside of the cabinet.

I think I have repaired this the best that I can, but it appears to be a very poorly designed overflow system.


The newer Corian sinks are made differently. There is no box around the overflow. The overflow tube has a 90 degree bend and glues into the sink without a box. Even with the new design, mine let go. Since there is not big box, it may be an even more difficult repair. It appears to have used hot melt adhesive from the factory. I am trying super glue because that is what was suggested at another site.

  • Let me know how the superglue holds. From what I read the superglue is great for the sink side, but doesn't adhere well to the plastic overflow part well. It also is hard to get it spread evenly and adhered well enough to be waterproof. – Stephen Ostermiller Feb 13 '17 at 22:34

Use two part epoxy after cleaning both the box and underside of bowl. Hold in place with duct tape over night. I sealed the next day with silicon but the epoxy alone was already tightly adhered and water tight. This was my third try in fixing using different sealants.

  • The two part epoxy should do better than the silicone alone. The silicone doesn't hold very well. – Stephen Ostermiller Aug 16 '17 at 18:32

protected by Community Feb 20 '18 at 17:27

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