Cast cement coping stone sealant.

[David Paste]

Hello all,

I have some (what I presume are) cast cement coping stones on a new wall. They leave a grey dust on your skin / clothes after sitting / brushing against them.

Can anyone recommend a sealant for these coping stones please?

I do not care if the colour or shade of them changes a little bit.

Thanks in advance,

Davod Paste.

[John Rumm]

A mix of SBR and water (or even waterproof PVA and water), will soak in and stabilise the surface. Brush off loose dust first...

[David Paste]

Thanks. What's SBR?

[Robin]

little if any sheen is

albeit that's not breathable.

[John Rumm]

It is a bonding agent usually added to things like mortar and concrete mixes, or to make waterproof cement slurry. It improves adhesion and workability and reduces the amount of water required to get good workability.

Available from any builders merchant and probably most diy places:

It is milky in appearance when wet, but dries clear.

[alan_m]

In my local Wickes this smaller 1l pot is not with the rest of the building supplies where you will find the 5L containers of SBR. It can be found on one of the other shelves with some other unrelated items :(

[Colin Bignell]

That sounds about right for my experiences of Wickes.

[David Paste]

Cheers!

[David Paste]

Once it's dried, it doesn't go milky again when it gets rained on does it?

[John Rumm]

IME, SBR no.

Some (so called "water proof") PVAs may partially soften again if kept wet enough long enough.

(generally a dilute solution will sink into the surface anyway rather than sit on it)