sikaflex 512 question

[Dazz]

Hi all I have a tub of sikoflex 512 and I was just woundering if anybody has used it to put a seal around the bath in the house just wondering if it’s good for that job

 

[Dazz]

Hi all I have a tub of sikaflex 512 and I was just woundering if anybody has used it to put a seal around the bath in the house just wondering if it’s good for that job

 

[Lenny HB]

Most PU sealants tend to go a bit pinkish after a few months and if you need to get if off it will be a right pig. I would use a good bacteria resistant silicon like Dowsil 785.

 

[Dazz]

Thanks Lenny

 

[Geo]

I would think not. silicone bath sealant is far more flexable
512 is not as giving and could pull tiles from the wall and too expensive to waste.

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[Emmit]

I have used 'Forever White' by Ever build (the same Co. as SIKAFLEX) with excellent results. Its the right stuff for your job.
Very good anti mould properties.
Available at Toolstation etc.

 

[Geo]

Good idea to fill bath before sealing too

 

[WestiesOnTour]

Hi
I work at jaguar cars and apx 10 years ago I used that sikaflex every day and even today thay still use sikaflex 221 and 512 to bond the windscreens and rear glass in the vehicles.

Its fantastic stuff great for bonding solar panels and things like that.
Personally would not use it in a bathroom as it sets solid and no movement.

Also if you do use 221 or 512 once opened try and use all the tube and it will go off within a month sets hard.

Hope this helps.

Jason.

 

[Just smiffy]

No, I filled a small gap for a temporary fix and after some bleach went on it it turned a horrible yellow...

 

[Lenny HB]

Good idea to fill bath before sealing too

Why?
My cast iron one ain't going to move.

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[Geo]

Why?
My cast iron one ain't going to move.

Yours is outside in the back yard anyway Lenny and there called Tin baths not cast iron

 

[MisterB]

Good idea to fill bath before sealing too

i think this has been a passed down DiY myth for years !

i have fitted dozens of baths and never had a problem not filling the bath before using a v good quality silicone sealant - even long before the days of anti mould sealants.

most modern baths will actually expand when filled with hot water (pressed steel, acrylic) so if the bath was filled with hot water then the gap to be filled will be smaller as the bath has expanded and when the bath contracts when empty there would be extra strain on the silicon pulling it apart as it stretched to fill the bigger gap. it would be under that 'stretching' pressure whenever the bath was not being used, which is far more often than when it is being used, and only 'normal' when the bath is being used. any sealant is more likely to fail when under constant pressure.

if the bath was filled with just cold water before applying silicone, then in theory it would contract, making the gap bigger. when you then applied the silicone and the bath, when empty, returns to its room temperature 'size', it will constantly compress up against the tiles when not being used and even more so when it is being used as the bath will expand compressing the silicone even further. that can cause tiles to be forced off the wall if they havent been fixed properly, especially if the compressed silicone can get behind the tile.

my advice and experience would be to suggest that you fit the bath properly, then tile and then apply silicone without filling the bath .....

 

[Geo]

i think this has been a passed down DiY myth for years !

i have fitted dozens of baths and never had a problem not filling the bath before using a v good quality silicone sealant - even long before the days of anti mould sealants.

most modern baths will actually expand when filled with hot water (pressed steel, acrylic) so if the bath was filled with hot water then the gap to be filled will be smaller as the bath has expanded and when the bath contracts when empty there would be extra strain on the silicon pulling it apart as it stretched to fill the bigger gap. it would be under that 'stretching' pressure whenever the bath was not being used, which is far more often than when it is being used, and only 'normal' when the bath is being used. any sealant is more likely to fail when under constant pressure.

if the bath was filled with just cold water before applying silicone, then in theory it would contract, making the gap bigger. when you then applied the silicone and the bath, when empty, returns to its room temperature 'size', it will constantly compress up against the tiles when not being used and even more so when it is being used as the bath will expand compressing the silicone even further. that can cause tiles to be forced off the wall if they havent been fixed properly, especially if the compressed silicone can get behind the tile.

my advice and experience would be to suggest that you fit the bath properly, then tile and then apply silicone without filling the bath .....

You make yourself look silly when you use personal opinions as expert knowlege

 

[MisterB]

not at all, this is wickes making a suggestion, just as i did, they say its a good idea, but listen to what they say ....

'this is so the silicone doesnt stretch and pull away when someone is having a bath' - they dont explain what the physics are, they just pass it off as a good idea. and that idea just gets repeated and it becomes fact by repitition.

if the bath is fixed properly to the floor using the legs, why would the bath physically reduce in size due to the weight of someone or the weight of water. weight in itself, would not alter the physical size of the bath. if the floor itself was not sufficient to take the weight of water, then i would accept that the distance between the height of the bath and the tiles would change, the weight of water in a bath fitted properly would not alter the height of the bath or the distance between the tiles, but a sagging floor would.


i offered my advice and opinion and gave reasons why i have that opinion and will continue fitting baths the way that i have done in the past, with no complaints from customers. if you can offer a logical reason as to why what i suggested is wrong, other than someone else told you to do it differently, then i am more than happy to change my opinion. if you just go off the logic used by Wickes, then shouldnt you also be in the bath when you apply the silicone? a 15 stone person in the bath along with all that water would also be a good idea, using their logic, or what happens when two people bath together?

rather than me looking silly ....... i did try to find anywhere on any good quality silicone sealant where it suggests filling the bath full of water before applying, i would take the advice of the product manufacturer long before anyone selling me the product. Sometimes having a different opinion doesn't mean that someone is silly. Perhaps having the willingness to question things, using your own personal experiences and reach your own conclusion is a good thing as opposed to being silly?

and just for clarity, i didnt say dont fill the bath. i gave reasons why (and suggested that) i dont think it is necessary

 

[MisterB]

If you can show me where a product specifically made to seal gaps in between bath and tile tells you to fill the bath with water then i will be surprised

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[Lenny HB]

Yours is outside in the back yard anyway Lenny and there called Tin baths not cast iron

Still got the tin one mummy used to bath me in that would have been 1950/51, used as a garden planter now, you don't get galvanizing like that these days.

 

[MisterB]

Still got the tin one mummy used to bath me in that would have been 1950/51, used as a garden planter now, you don't get galvanizing like that these days.

i remember mixing up plaster for the plasterers on jobs in a galvanised bath using a shovel (no, i wasnt in the bath the plaster was being mixed in it LOL)- long before the days of the electric paddles that they now use !!

 

[tonyidle]

Still got the tin one mummy used to bath me in that would have been 1950/51, used as a garden planter now, you don't get galvanizing like that these days.

Or Mummys.

 

[Geo]

View attachment 393952View attachment 393953

If you can show me where a product specifically made to seal gaps in between bath and tile tells you to fill the bath with water then i will be surprised

Well im not here to convince you of anything, it appears plumworld, Wicks, B&Q, and the like all suggest filling the bath also plumbers Forums such as these <Broken link removed> also agree, so im quite happy with their advice.
I wouldn't expect the product to give tips as the dont know what your doing with it
Im also happy to concede if it make you feel better