Cutek Extreme CD50 20L

CUTEK Extreme CD50 is supplied as a clear oil. Clear CD50 protects against moisture-related movement but does not prevent the timber from naturally lightening, greying or developing a silver weathered patina under sunlight and UV exposure.

If you want to maintain the freshly oiled appearance or alter the timber colour, mix in a compatible CUTEK Colourtone before application. Colourtones add pigment that slows the silvering process. Colour retention varies with timber species, preparation, exposure, design and maintenance, so always test the complete system on an offcut or inconspicuous area first.

• Deep penetrating protection rather than a surface film
• Controls liquid and vapour-phase moisture within timber
• Helps minimise warping, cupping and splitting
• Unique self-healing effect migrates toward cuts, fastener holes and damaged areas
• Will not peel or flake like a film-forming coating
• Enhances the natural grain, texture and character of timber
• Simple maintenance—clean and apply a thin recoat when required
• Australian made for Australian conditions

• Timber decks and boardwalks
• Weatherboards, cladding, shingles and fascia boards
• Fences, posts, gates, screens and shutters
• Exterior doors, garage doors and joinery
• Beams, plywood and engineered timber products
• Outdoor furniture and timber around spas and pools

Coverage varies considerably with timber species, density, porosity, surface profile, preparation and application method. CUTEK provides the following indicative coverage ranges per litre:

• New dressed hardwood: approximately 10–20m²/L
• Old restored dressed timber: approximately 7–9m²/L
• New rough-sawn timber: approximately 7–9m²/L
• Old restored rough-sawn timber: approximately 4–7m²/L
• Shingles and shakes: approximately 2–5m²/L

These figures are guides only and should not be treated as a fixed project allowance. Highly absorbent, weathered or rough timber will use more product. Allow for the required number of coats when calculating total project coverage.

1. Start with bare timber. Paint, polyurethane, stains, non-CUTEK oils and other film-forming coatings can block penetration and must be completely removed by stripping, sanding or an appropriate combination of both.
2. Clean the timber thoroughly. Remove dirt, grease, mould, tannin marks, iron staining and preparation residues. New timber may also benefit from cleaning to remove mill glaze and open the grain.
3. Rinse completely. Chemical or alkaline residues can interfere with the finish and may cause staining.
4. Allow the timber to dry. Timber moisture content must be no more than 17% before coating.
5. Test penetration. Sprinkle water onto the surface. If it absorbs, the timber is generally open enough to accept CD50. If it beads, further preparation may be required.
6. Test colour and drying. Apply the complete system to a representative test area before coating the whole project.

1. Protect adjacent surfaces, plants and areas that are not being coated.
2. Stir thoroughly from the bottom of the can before and during use. If using a CUTEK Colourtone, mix it completely into the oil.
3. Apply a thin, even coat with a decking brush, paint pad or lambswool applicator.
4. Allow the first coat to fully penetrate, diffuse and dry until the timber feels dry and non-greasy before applying another coat.
5. For prepared exterior timber, follow CUTEK’s project guidance—typically two thin coats. Dense finished hardwoods may perform better with multiple thin applications rather than heavy coats.
6. Do not allow excess oil to pool on the surface. Over-application or recoating too soon can leave the timber greasy or tacky.
7. Avoid traffic and exposure to contaminants until the oil has properly diffused and dried.

CD50 gradually fades instead of forming a film that cracks or peels. For maintenance, clean the timber and apply one thin coat when the surface no longer beads water or when colour refreshment is required. Horizontal, highly exposed surfaces such as decks generally need maintenance more frequently than protected vertical cladding.

If the timber has heavily greyed, developed tannin or iron staining, or accumulated excess pigment, restore the surface appropriately before recoating. Maintenance frequency cannot be fixed because it depends on timber species, exposure, aspect, design, preparation, traffic and the chosen Colourtone.

• Maximum timber moisture: 17%
• Dry heat resistance: up to approximately 80°C
• Water resistance: very good resistance to fresh and salt water, but not suitable for immersion
• Do not thin: apply as supplied, with a compatible CUTEK Colourtone added only when desired
• Penetration and drying vary with timber density, porosity, temperature, airflow and weather exposure
• Cold conditions thicken the oil and can increase the risk of over-application
• Not suitable for food-preparation surfaces
• Check the latest CUTEK technical data sheet and safety data sheet before use

Why SEALIX recommends it: CUTEK Extreme CD50 is one of our preferred systems for exterior timber where deep moisture protection, dimensional stability and straightforward maintenance are more important than creating a surface film. It penetrates the timber and can be cleaned and recoated without stripping a failed film.

• Best for: large decks, extensive cladding, commercial exterior timber and ongoing maintenance programs.
• Colour advice: clear CD50 allows natural silvering. Add a CUTEK Colourtone when maintaining the timber colour and improving UV colour protection is the priority.
• Application advice: remove existing coatings and prepare to clean, bare, dry timber. Apply thin coats and do not apply the next coat until the previous coat is fully dry and non-greasy.
• Pack advice: the 20L trade pack is the efficient choice for large areas, but calculate coverage before ordering to avoid unnecessary leftover material.

A trade-size pack for large decks, extensive cladding, commercial timber projects and ongoing maintenance.