Monobloc tap for small hole

[Tombowombo]

Hi there!

I have an old reclaimed porcelain sink for which I am looking for a mono mixer tap (second hole to be blanked off) Have purchased two now and neither fit the hole!

Hole is square (ish) with minimum dimension of around 30mm. First tap had a brass threaded collar which was intended to pass right through the hole and secure with backnut, it is too big by about 2mm. Second tap was (what I consider to be) more common monobloc design with small lengths of stud and horseshoe shaped washer. Combination of flexi tails and studs do not fit...

Does anyone have any suggestions of manufacturers who make smaller mono mixers? Or does anyone know how I can reliably widen the hole in a ceramic sink without cracking it?

I think if I take an angle grinder to the brass collar of the first tap and slice a section out of each of the four sides I can get it (and flexi tails) to fit. I would probably need to create some sort of brace across the bottom ends to push them outwards so that the backnut would still get purchase. Not confident in this solution, but will give it a go if I have to.

Thanks in advance.

 

[Best]

I would reckon go with widening the hole in the basin. Round diamond file but used only on down stroke, (preventing chips to top of basin) to gradually file the hole bigger.
Unless a Dremell tool with diamond buff would suit.
Wear protective eyeglasses.

 

[Harvest Fields]

I would reckon go with widening the hole in the basin. Round diamond file but used only on down stroke, (preventing chips to top of basin) to gradually file the hole bigger.
Unless a Dremell tool with diamond buff would suit.
Wear protective eyeglasses.

Always been scared to try this with the kind of luck I have

 

[Welder]

Right. Just bite the bullet.
Get yourself a 35mm diamond tile cutter and use the corner of the existing hole to start it off. Once started straighten up and use vertically.
Use plenty of water to keep it cool and don't go too fast. In 15 mins you'll have a nice neat 35mm hole for any monoblock.