Astroflame Passive Fire Protection Products

Trade Name ASTRO Non Dark Sealer

Non Darkening Sealer Coat

Non Darkening Sealer Coat minimizes the risk of darkening the original surface where a clear anti graffiti coating is to be applied.

A general non darkening sealer for concrete and concrete products such as cement render, mortars and grouts, fibro cement, etc.

Seals natural stone against water penetration - reducing mould and mildew discolouration

Improves spread rate of anti graffiti paint / coat.


Non Darkening Sealer


Non Darkening Sealer is a clear 100% acrylic sealer dispersed in water making it low odour, non-flammable and low toxicity.

Used as a transparent sealer for porous surfaces, such as, brick, mortar, concrete, render, porous stone and bare timber prior to application of Anti-Graffiti Paint. It is used to avoid darkening the original surface - for example bricks may not show any darkening when an anti-graffiti coating is applied but the mortar may do.

To test the effectiveness of Non Darkening Sealer we strongly recommend a small discrete trial application be carried out.

It is not required over sealed or previously painted surfaces.

Can also used, on its own, as a general non darkening sealer for concrete and concrete products such as cement render, mortars and grouts, fibro cement, etc.

It is also suitable for sealing sandstone and other natural stone products against the ingress of water reducing mould and mildew discolouration.

Excellent adhesion to concrete and most common building surfaces.

Available in 5 litre containers.


Application is by brush, spray or roller.

Apply one good coat of Non Darkening Sealer over a clean, dry substrate - first ensuring that any brick acid/etch cleaner used has been thoroughly rinsed off.

Non Darkening Sealer is milky white when first applied but dries clear.

For Non Darkening Sealer to work it is important that it be allowed to dry fully before applying any Anti Graffiti finishing coats. Allow at least 4 hours under good drying conditions, but preferably overnight.

Important: Avoid using a paint brush when applying Non Darkening Sealer to surfaces subjected to efflorescence (i.e. salt deposits on cement substrates). Efflorescence can be difficult to detect on light coloured surfaces and will produce a milky effect on a clear finish if disturbed during application (i.e. by shear action of using a brush). Roller or spray application is recommended where efflorescence may be present.



o Appearance

o Specific gravity

o Solids by weight

o UV Resistance

o Flammability

o Service temperature

o Shelf life as supplied

Application Data

o Application temperature

o Open time

o Drying time

Typical Values

White liquid 1.02

1.04 24



Water based Non-flammable

20oC to 90oC

12 months in original unopened container.


Minimum 8oC 30oC

Approx 20 minutes at 25oC

Touch dry in 1-2 hours depending on conditions.
Re-coat with Anti Graffiti Paint after 24 hours.


To Order & Specify

To Order & Specify: Quantity / Trade name / Product ref
Typical wording:
3 / Astro Non Dark Sealer / ANDS5

Health and Safety

Refer to COSHH sheet supplied with product.

As part of our policy of ongoing improvements, we reserve the right to modify, alter or change product specifications without giving notice. Product illustrations are representations only. All information contained in this document is provided for guidance only, and as ASTROFLAME FIRESEALS LTD has no control over the installation methods of the products, or of the prevailing site conditions, no warranties expressed or implied are intended to be given as to the actual performance of the products mentioned or referred to, and no liability whatsoever will be accepted for any loss, damage or injury arising from the use of the information given of products mentioned or referred to herein.

The above information to the best of our knowledge is true and accurate and based upon current test data and is supplied for your guidance only. Customers should satisfy themselves to the suitability of the product in its intended use and no guarantee is given or implied since the conditions of actual use are beyond our control. ASTROflame (Fireseals) Ltd, disclaim any liability for loss, damage or other expense arising from the use of information, data or products mentioned or referred to and reserve the right to change any details or specifications without notice.

Astroflame (Fire Seals) Ltd. Intumescent House
Unit 8, The IO Centre, Stephenson Road, Segensworth
tel 0800 023 2482
(01329 844500)
fax 0800 023 2483
(01329 844600)
tel +44 1329 844500
fax +44 1329 844600



Email Astroflame