Skimming & Repairing Cracks

TUTORIAL 8:

SKIMMING AND REPAIRING CRACKS

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Determining your product requirement:

• Measure the surface area you wish to
• Determine which products are needed for the surface you wish to paint and the finish you wish to achieve.
• Check the Theoretical Spread Rates (TSR) on each of the specified products and see how many coats of each are recommended, then calculate what quantities of each product you will require, remembering to make adjustments for the porosity for each surface. TSRs are based on products applied to smooth, sealed (E.g. an unsealed scratch plaster surface will absorb more paint than a sealed smooth one, so allow for a lower spread rate on porous surfaces).
• Check out the specifications on all the top coat choices (referring to the relevant data sheets) and decide which is right for

NOTE: It is important to identify the type of crack and to then open and expose it, below are the various types of cracks you may encounter.

PLASTER CRACKS (<4mm)

• Rake out cracks to a minimum of 3mm wide and

LARGE PLASTER CRACKS (>4mm)

• Open large plaster cracks using an angle grinder in an inverted V-shape to 5mm wide and Remove dust and friable material.

STRUCTURAL CRACKS

• Structural cracks should be referred to an engineer for remedial procedure as there is a possibility that the residence/building might require

FLASHPATCH EXTERIOR CRACK FILLING

Surface Preparation for Cracks

1. Open the crack using a scraper and remove all loose friable
2. Apply a coat of AcrySeal to all areas of the crack and allow to
3. Patching a crack to match a surrounding wall finish is an FlashPatch has been designed to accept addition of sand (Plaster sand, river sand etc.) in order to simulate the surrounding wall texture. If adding different sand types then do not exceed adding more than 10 to 15% of the weight of FlashPatch being used, once the sand has been added a good working consistency must be achieved by addition of small amounts of water.

NOTE: Paintcor’s high build textured paint range can be used as top coats to hide excessively scarred walls. Refer to SatinTex, GranTex and RippleTex product data sheets.

Application Method to Cracks

1. Do not dilute FlashPatch for filling cracks unless addition of sand is necessary to simulate rough
2. Using a putty knife/scraper, fill the crack or hole using Paintcor’s FlashPatch
3. Smooth product while still Avoid sanding as FlashPatch Exterior is waterproof and does not sand well.
4. If damaged area is more than 5mm deep, repair damage with sand, cement and AcryLatex or multiple coats of FlashPatch Exterior. Allow to dry thoroughly between
5. FlashPatch Exterior does not need to be primed before

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FLASHPATCH INTERIOR CRACK/HOLE FILLING

Surface Preparation for Cracks

1. Open the crack using a scraper and remove all loose friable material, remove wall plugs and dust from

Application Method to Cracks

1. Using a putty knife/scraper, fill the crack or hole using Paintcor’s FlashPatch Interior. Scrape any excess patching from the surface surrounding the crack or hole, allow to
2. Sand to a smooth finish. Remove sanding dust before painting. FlashPatch Interior does not need to be
3. If damaged area is more than 5mm deep, repair damage with sand, cement and AcryLatex or multiple coats of FlashPatch Interior. Allow to dry thoroughly between coats.

FLASHSKIM INTERIOR AS A SUBSTITUTE TO GYPSUM PLASTERS

Surface Preparation for skimming

1. Brush plaster to remove all loose friable
2. Ensure plastered wall is straight. FlashSkim cannot be applied at more than 5mm at a time. Therefore, Gypsum plaster would have to be used to correct or straighten walls that have been floated

Application Method for Skimming

1. Ensure the plastered wall has been floated straight and has
2. Seal the new plaster with Paintcor’s AcrySeal, diluted 1:1 with water. Allow 45 minutes @ 25°C to
3. Apply a liberal coat of Paintcor’s FlashSkim to the surface with the edge of a steel trowel, allowing the product to fill in all imperfections.
4. Scrape any excess FlashSkim off your steel trowel onto a square trowel, then, using a firm and consistent motion, skim the excess FlashSkim off the surface with the steel trowel, leaving a thin, semi-transparent skim coat behind. Scrape off the excess FlashSkim from the steel trowel back onto the square trowel and repeat the process. This will result in a durable, smooth, white surface after Allow up to 45 minutes at 25°C to dry before over coating.
5. Sand any ridges or imperfections to a smooth Remove sanding dust.
6. Paintcor’s FlashSkim requires no priming before painting. Apply two top coats of your choice. Allow to dry between

NOTE: FlashSkim CAN NOT be used on Exterior applications, please see FlashPatch Exterior DA should you wish to skim an exterior surface.

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