Which silicone sealant???

Jan 05, 2010 14 Replies

Ok probably a dumb question, but how do you choose the "right" sealant for the job?



If I understand correctly,



Low modulus requires little effort to move, ie very flexible. High modulus being the opposite is quite stiff.



Acetoxy cure is quick to cure but does not stick as well to some surfaces. Neutral cure is slower to cure but sticks like **it to a blanket.



Now having said that what do I need to install a bathroom sink waste, any recommendations? and what would I need to seal around the base of a tiled wall/shower tray and around shower components where they exit the wall?



My instinct says to get something Low Modulus and neutral curing, presumably with anti fungal gunk, but to be honest I have NO idea.



thanks



Vernon


Use Dow Corning 785. I used it for our en-suite and it's really good stuff.

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Why do you think you need silicone for a sink waste ?

"slider" wrote

Yes it's probably 3 times the shed cheapo stuff, but quality costs.

Phil

It's not that expensive when you compare it to the usual branded versions either (Unibond etc). £4.89 from Screwfix

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Agree. They will leak. Get a "basin mate". It will be the best £1 you ever spend. I have fitted two of these on two sinks and neither have leaked at all.

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Well I had a quick look in B&Q (closer than screwfix, almost always ££ more, but handy for looking at items) and the basin waste had instructions that said to apply sealant, cant remember where exactly, IIRC it was to the plastic washer, and possibly under the plug housing/basin.

Are you suggesting that I don't need any?

Just had a look at basin mate in Toolstation catalogue, looks a lot more sturdy than the plastic washer. Presumably with that, you do not need to apply sealant anywhere? What about between the basin & plug housing?

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Thank you

If it does the job then it is worth paying for! Nothing worse than having to do the job twice. Out of interest it says that it is fast curing, so presumably it is acetoxy and low modulus? (Still trying to get my head around the different properties)

Well I wasn't sure where exactly you were going to use it ..I'm trying to remember what ,if anything ,I used when I fitted my w/h basin .I might have used Plumber's Mait but then again it might have been LSX which is clear silicone afaik .

I wrote a FAQ on sealants some time ago ... it used to be on uk-d-i-y web site, let me know if you want a copy.

I used DOW 785 for this task.

Best way to bed in wastes is with a bead of sealant ... between washer & underside of basin .... I also put a bead between waste and top surface of basin.

LSX is good ... esp[ on male to female thread joints, but too expensive for fittings wastes.

Rick, thank you is this the one?

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have bought a chrome waste, "plummers mate" and a tube of 785 today, so I intend to bed the waste on silicone in the sink, and use the plummers mate underneath.

I shall report back, success or failure!

I see Dow Corning 785 is available in white, clear, beige and grey.

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