Sealing waste against rough underside of acrylic bath

[IngeJones]

I am a DIYer, with no trade qualifications.

I have bought an acrylic bath, and a normal waste set (ie not the banjo overflow type). The waste set has a chrome plughole, (which is supplied with a sort of soft polystyrene gasket that goes between it and the smooth inner surface of the bath), and a screw passes through the metal plughole through into the plastic part underneath. The underneath assembly is supplied with a flexible, but not very compressible, rubber or nitrile gasket.

I have had successful experience fitting this type of waste to kitchen sinks, but those tend to be smooth underneath. The bath is very rough underneath, with what appears to be glass fibre reinforcement, and I don't expect the rubber gasket will be able to make a very good seal against it.

What are people doing about this situation? Would a bead of silicon sealant between the rubber and the bath be a good idea, or might it react against the bath material?

 

[seco services]

useally a bead of clear silicone.

 

[Paul Barker]

Actually the rubber gasket does work, but you must not mix and match, rubber only works dry. Aslong as you compress rubber dry against the uneven surface it finds the shape of that surface.

There are some rubber gaskets which are not pliable or thick enough, which will never work. In those situations plumbers pull out of the bag their personal favourites. Mine is hemp and paste.

 

[IngeJones]

So, I'll try the rubber dry first, and see what I think of the fit. If I decide it's not satisfactory I ditch the rubber gasket altogether and go for something like the paste and hemp idea - *or* the silicon? Is there any type of sealing paste I must definitely avoid on an acrylic bath? Is Plumbers Mate ok?

 

[Paul Barker]

I don't think you are meant to user any but it's better than water leak.

I use boss white with hemp when it has to be used. I don't think plumbers mate works with hemp in the same way. Jet blue works with hemp though, quite a few people only use jet blue as it's pottable ok for gas and blends well with hemp for emergencies.

Last bath I fitted sealed dry.

When I was fixing washing machines we used a gum like sealant which stuck really good, as you have time while assembling a bath you could use it. It is totally dependable probably the most waterproof method of all time. I have some in the van for emergencies. Can look up the name if you want to try it. Not cheap of course.

 

[IngeJones]

I looked again at the fitting, and what I described as the soft polystyrene for the inside gasket is not that at all, it's like a very soft sorbo type of rubber. I was thinking, instead of using that inside, instead place it between the nitrile gasket and the underside of the bath, as it will easily adapt to the irregularities of the rough surface. Then just use a bead of silicone to bed the metal part onto the bath surface instead of the gasket that I "borrowed". What do you think of that idea?

 

[seco services]

I use boss white with hemp when it has to be used. I don't think plumbers mate works with hemp in the same way. Jet blue works with hemp though, quite a few people only use jet blue as it's pottable ok for gas and blends well with hemp for emergencies.

surely you don't use boss white & jet blue on bath wastes.

 

[Paul Barker]

If I had to it would work but no. What's your various methods?