Create a bed of silicone without it sticking

[MarkSmith]

Hi,

Apologies if this is the wrong forum - I'll repost in a different section if there is a more appropriate option.

I am fitting a wall-hung basin to a tiled wall. It rocks very slightly due to either the basin or the wall not being perfectly flat. I am concerned this means that pressure is on a very small area of the tile/basin and that this may cause one or other to crack. If I tighten the nuts too hard, to stop the rocking and keep it secure, I fear I will crack a tile.

My idea: create a "gasket" of say 1mm of silicone sealant on the back of the basin, to cushion it against the wall, spreading the load away from the small points of contact.

However I do not want the silicone to adhere to both basin and wall, as it will make it (practically) impossible to remove.

Is there any way I can cause the silicone not to stick to one or other surface? For example, by putting a film of some sort on one of the surfaces? The best idea I have so far is to paint the tiles behind the sink with some cheap emulsion paint, to which the silicone will stick -- then when I want to remove the basin, the paint will peel off the tiles. Any improvements on this idea please?

Thanks!
-Mark

 

[oldbuffer]

Cling film

 

[StephenStephen]

cooking oil?

 

[Alec_t]

Can't you just use (silicone) rubber washers between basin and tile?

 

[JohnD]

ordinary "tablet" soap. Use a paintbrush and water to get it workable, then leave it to dry and harden. The sealant probably contains no water so will probably not disturb or soften the soap when you apply it, but it can easily be washed off later.

You could also use EDPM draught excluder, probably two strip of white "E" section instead of silicone, and stick it to the back of the basin.

 

[Terrywookfit]

Why would you want to remove it.
A BEAD ALONG THE TOP EDGE AND SIDES which is a normal seal will prevent it rocking.

 

[MarkSmith]

Thanks for the replies all. Some useful suggestions.

Why would you want to remove it.

All sorts of reasons. Maybe a plumbing problem inside the boxing which requires the boxing to be removed. Re-tiling is less costly than re-tiling and replacing sink. A few years ago I moved a basin about a foot to the right to accommodate a shower cubicle. Maybe because someone drops something into the basin, cracking it -- which is the reason I'm doing this at all. All sorts of reasons.

Anyway, I performed a scientific experiment: four pieces of tile, with (respectively) nothing, water, soap, and cling film applied. Silicon on, second piece of tile on top. Left overnight, tested the next day to see which would come apart.


And the winner is...

Cling film

I didn't try cooking oil, not having any to hand, but the other three were stuck tight.

So I put several beads of silicone over the back of the basin , put clingfilm on the wall (very easy as it holds itself up), put the basin up with some temporary spacers at the bottom, and gradually tightened it over the course of three or four hours, and now it's rock solid.

Thanks all!

 

[John D v2.0]

Anyway, I performed a scientific experiment: four pieces of tile, with (respectively) nothing, water, soap, and cling film applied. Silicon on, second piece of tile on top. Left overnight, tested the next day to see which would come apart.

That's epic! You are a scientific genius. I'll nominate you to be the DIY not myth buster!