Silicon rubber washer orientation

[Buk]

Hi guys,

I've just taken delivery of a pull-out monobloc tap that has a large (M30?) brass nut to hold it to the sink/worksurface.

Also supplied are two silicon rubber washers, to be used one above and one below the surface. This is all clearly described in the (minimal) fitting instructions.

The one piece of information missing is the orientation of the washers, which have smooth side and one "ribbed" -- ie, one side of the washers have two concentric raised ribs around the circumference.

My question is: should the ribbed side be oriented towards the sink surface (stainless steel) with the smooth sides towards the base of the tap body and the top of the brass nut respectively; or vice versa?

Or doesn't it make any difference?

(This is possibly a trivial question, but I intend fitting the tap before I mount the sink and fitting the sink is going to be a labour of love given limited room in which to tighten the sink clamps; so if there is a proper orientation I'd rather get it right first time and avoid having to go around.)

Thoughts? Requests for further info?

Thanks all.

Buk

 

[joni os]

Put the ribs against sink and use poly washer underneath, even if not supplied. Tighten by rotation against poly washer so rubber washer gets compressed but not distorted by rotation.

 

[snowhead]

Ribs to the sink top and bottom.

As you think.
The ribs are there to make a better seal onto an uneven worktop surface.

And don't put silicon or any other selant onto the seals, they'll spread out from under the tap.

 

[Buk]

Put the ribs against sink and use poly washer underneath, even if not supplied. Tighten by rotation against poly washer so rubber washer gets compressed but not distorted by rotation.

Thanks Joni.

A couple of follow up questions:

1. "Poly washer" -- polythene, polycarbonate? (Where can I buy same?)
2. The "mating" surface of the big brass nut is not flat, but rather slopes at about 15° from the outer circumference towards the inner. (Not easy to describe so I'm attaching a photo. ) Do you still advise the "poly washer"?
3. The tap is surprisingly big (bigger than I though looking at an image online) and the sink, whilst not the cheapest, is not a premium model either, and the SS is listed 0.9mm thick.

My fear is that given the weight and leverage created by the height, mounting it directly to the relatively thin SS will result in a wobbly tap at best and could possible distort the sink surface itself.

I have some 1.5mm galvanized steel sheet. My thought is to cut out a piece, put a 31mm hole in it, and shape it to be as large as can be accommodated by the flat area around the tap hole; in order to spread the load over a wider area of the stainless steel. eg.

Does that look/sound like a good idea?

Would you still employ the "poly washer"?
If so, this would go between the nut and the silicon rubber washer?

Thanks, Buk.

 

[joni os]

Forget galv steel it will rust. If necessary cut stiffener from brass push plate (door), also easy to cut hole in brass. Polythene washers obtainable from plumbers merchant or make own from side of 4 pint milk container. Principle of poly. washer, to stop rubber washer rotating during final tightening of brass nut. Smear of silicone between brass plate and SS sink will,once cured, add stability to base of tap by resisting rotation.

 

[student plumber]

Most SS sinks are less than 1mm thick, if not all?
Our tap wobbles and I have seen plenty at customer's homes.
It's because the steel is that thin.

I did have to change a kitchen tap, both existing and replacement had regular horseshoe washers.
But the existing tap also had a bit of heavy duty plastic, about 1/8" thick, between underside of sink and horseshoe washer.
It was a plastic tube about 1" long and had a triangular flange on one end which was against the sink.

I don't know if it was part of original tap or third party but it fitted the new one so I used it.

It worked, perhaps you might find one?

 

[moonlight]

Try using a top hat might help with the wobble.

 

[Welder]

You can buy a plastic 'brace' that spreads the load over a greater area for this type of eventuality. Many decent tap suppliers supply them as sinks are like Fords now and made of tinfoil . I'll try and find a picture.

 

[Welder]

Screwfix item 5287J HTH.

 

[ShaunCorbs]

You can buy a plastic 'brace' that spreads the load over a greater area for this type of eventuality. Many decent tap suppliers supply them as sinks are like Fords now and made of tinfoil . I'll try and find a picture.

You mean the triangle support bracket / washer