Water escaping from hole under sink!

[humptyd]

Well, I'm back again and it's much sooner than anticipated. I hate Easter

Right, water running into an unplugged sink which was a bit blocked so water wasn't escaping as fast as it should but nothing to worry about. I then noticed that water was escaping through the hole in pic 2 which is looking up at the bottom of the sink. There is an exact same hole on t'other side of the sink but that seems ok.

I did a bit of plunging and although it wasn't that badly blocked before, maybe 10% only, it did stop the water coming out when free running. However, fill the sink up to just below the overflow wotsit, let it go and after a few secs or so, about an inch of water will come out of the hole. What the?!?

In pic 1 there are 2 holes in the metal as you look down plug hole (shown by the amateurish pointing) which have always been there, may or may not have somert to do with it.

Haven't got a clue really, any pointers gratefully received.

 

[tamz]

Basins are made double skinned and the overflow runs down a (sealed ) section to the grating and to the drain through the holes marked in picture . The holes in picture 2 are for hanging the basin when it is made in the factory. When you release water and the basin is full and slow draining, it will fill this overflow section of the basin (through the holes in the grating) and drain at the same rate
There must be a gap somewhere between the overflow section of the basin and the rest of it. You could fill the hole in 2 but it will probably start to smell after a wee while because of the trapped water. Maybe best to replace the basin or you could fit an unslotted grating which will seal between the space but you will have no overflow.

I could have perhaps explained this better but you should get the gist of it.

 

[humptyd]

No, sorry, I don't get it. At least I think I don't

The grating (those 2 square holes, opposite each other, as you look down the plug hole?) takes in water as it drains and that's the reason for it coming out of hole in pic 2?

I don't get why this has just started happening, will something be blocked somewhere?

 

[tamz]

The grating (waste) is the whole chrome bit with the 2 square holes opposite each other as you look down the plug hole. These square holes are to allow the basin to overflow (from the hole at the top) down through the inside of the basin to the drain.
A basin is made double skinned i.e. a basin inside a basin and is hollow in between. The overflow comes down between the 2 skins in a sealed section. This inside part is leaking allowing water to pass through. It cannot be repaired as you can never get to it so you have 2 options.
1 Bin the basin and get another.
2 Fit an unslotted grating i.e. one without the square holes.

Here you will see the difference
http://www.bathroom2u.com/sagittarius-slow-drain-basin-waste-unslotted-p-3569.html

 

[humptyd]

Ok, ta. The tool box can go back in the cupboard then