METASET® SCRATCH COAT

Product Description

METASET® Scratch Coat is a three-component slurry screed, based on Stirling Lloyd’s, now GCP Applied Technologies, unique ESSELAC® advanced resin technology and extensive experience in the development of high performance levelling screeds that cures rapidly by chemical reaction.

Uses

METASET® Scratch Coat provides an economical solution to levelling substrates prior to the application of other GCP coatings. It is suitable for use on both concrete and asphalt. It is designed to fill all voids, blowholes and level tamped surfaces.

Technical Data

Surface Preparation

It should be stressed that the success of any coating or repair system is dependent on the thoroughness of the surface preparation.

All substrates must be clean, dry and structurally sound. All preparation must ensure the complete removal of all substances that are detrimental to the bond such as laitance, dust, dirt, oils, fat, waxes and chemical contaminants.

Concrete

New concrete decks should be a minimum of seven days old. If additives, cement replacement or curing agents have been used please contact our Customer Services Department.

All concrete decks must be prepared by suitable mechanical means ⁽³⁾ such as vacuum blasting to provide a sound surface. All laitance should be removed so that the aggregate in the deck is visible.

^{1_{METASET® Scratch Coat is supplied in both winter and summer grades. The winter grade is supplied automatically (UK only) between the October 1st and March 31st with additional powder catalyst to add to the mix to increase the speed of cure at temperatures below 10°C. For temperatures outside this range please contact our Customer Services Department.}}

^{2_{Working Life and Cure Times are based on the material, substrate and ambient temperatures being at the stated level with the exception of the 30oC condition where storage requirements demand the material temperature does not exceed 25oC. The values stated above are based on laboratory conditions and should be used as a guideline only.}}

^{3_{Water Jetting is not an acceptable method of mechanical preparation.}}

Oil and grease can be removed by scouring using a water-soluble de-greaser. If acid etching is used care should be taken to ensure that the resulting residues are completely removed.

Asphalt

METASET® Scratch coat is not suitable for application to deferred set reinstatement materials. Adhesion testing is recommended on any asphalt surface less than 28 days old.

The use of heat with a naked flame e.g. triburners, to dry asphalt surfaces must be avoided. The use of naked flames reactivates the asphalt binder, which can then impair the adhesion of the system to the surface.

Oil and grease can be removed by scouring using a water-soluble de-greaser.

Application

Prior to application ensure the substrate is completely dry and above the dew point.

Primer

No primer is required on asphalt substrates. Concrete substrates must be primed using either PAR1 or PA1 primer. The relevant primer must be allowed to cure before application of METASET® Scratch Coat commences. Please refer to the relevant datasheet for further information.

METASET® Scratch Coat

METASET® Scratch Coat consists of a pre-packed base resin component, a bag of powder catalyst (BPO) and a filler component.

Ensure the job is prepared before starting the mixing operation. A steel or plastic bucket is an ideal mixing vessel. Ensure that the vessel is clean and large enough to contain the pack size being mixed. Do not split the kits.

Shake the container of resin thoroughly and then pour it into the mixing vessel. Using a mechanical mixer, such as an air-driven drill (400-800rpm) and mixing paddle, start to stir the resin.

Whilst continuing to stir, add the BPO hardener and mix for a few seconds. This initiates the ‘working life’ during which time the Scratch Coat must be used. So, without stopping, add the bag of fillers and mix thoroughly until all the fillers are wetted out.

(Additional catalyst is required at temperatures below 10oC. In the UK additional catalyst is automatically provided during the months of October to March. This should be added to the resin component and mixed in immediately prior to adding the fillers).

METASET® Scratch Coat must be placed and finished during the working life. Pour the material out onto the substrate and spread out using a flat edged rubber squeegee.

Towards the end of the ‘working life’ polymerisation starts, the viscosity increases i.e. it becomes stiffer, the temperature rises and the material starts to gel. Do not try to place or work the material at this stage.

Remove any masking tape before the material starts to gel.

Ensure that the METASET® Scratch Coat is fully dry to the touch before overcoating. 

It is essential that good air circulation and ventilation be provided during application in enclosed spaces to allow full cure. The treated substrate should not be opened to traffic until the surface is dry to the touch.

Coverage

METASET® Scratch Coat: 2 kg/m²/mm

The required coverage rate will vary with surface texture and porosity.

Cleaning

All tools and equipment should be cleaned with acetone before the material is allowed to cure.

Packaging & Storage

METASET® Scratch Coat is supplied in a kit consisting of:

Summer Grade - 20kg of graded fillers & 4.18kg of resin & 70g of BPO

Winter Grade - 20kg of graded fillers & 4.18kg of resin & 120g of BPO

All components of METASET® Scratch Coat should be stored in cool, dry, protected conditions, out of direct sunlight and in accordance with the relevant site Health & Safety regulations. Storage temperature must not exceed 25oC. Do not store near naked flames or foodstuffs.

Stored in unopened containers, the correct conditions, the components have a shelf life of twelve months. If your product is more than twelve months old you must contact GCP before use.

Health & Safety

Please refer to our Safety Data Sheets for further information.

General Information

METASET® Scratch Coat is part of a wide range of specialist waterproofing, surfacing and repair materials manufactured and supplied by GCP. If you require any further information on this or any other of our products, please contact our Customer Services Department or visit www.gcpat.com.