TWA Clear Wood Preservative

APVMA Registered Product No 60813


TWA CLEAR WOOD PRESERVATIVE (CWP) is intended for the protection of Timber and timber structures from degrade by wood destroying fungi and insects in above-ground situations. It is primarily intended for the protection of non-durable timbers (ie: oregon, meranti, radiata pine) that may be used in building and joinery applications. It can also be used to endseal pressure treated timber (ie: CCA, Tanalith-E, ACQ or LOSP type) that has been cut or machined and is to be used above ground (H3) CWP contains a fungicide (zinc naphthenate) and insecticide (permethrin) for broad spectrum of protection. In particular the permethrin has been added to provide additional protection to timber from borers and termites. These constituents have been selected for their effectiveness in protecting timber and their low toxicity to humans. CWP also contains water repellent which contributes to dimensional stability of the timber.




Paints and Stains, Oil based paints, primers, undercoats and stains can be applied 3 days after treatment in fine warm weather and after a week in cool weather (< 20°C) If water based paints (acrylics) are to be used on CWP treated timber it is recommended to first coat the timber with an oil based primer. Note: CWP may slow the drying rate of primers. It is recommended to allow at least a further 24 hours drying time for the primer in addition to the manufacturers’ normal instructions. If in doubt always first check the suitability of a surface finish or consult the manufacturer.

Fasteners and Fixings

CWP is not corrosive and should not cause any problems with fasteners and fixings. However when using timber in situations that are open to rain and weather, galvanised or corrosive resistant fixings should be used to prevent stains.

  • Appearance: Amber coloured, clear liquid
  • Odour: Typical of zinc naphthenate
  • Density: 0.87kg/L – 20oC
  • Flash Point: >66°C (closed cup)


CWP timber Protective is a penetrating timber preservative and not a coating that remains on the surface. It is ideal for application to timbers used in window frames, external doors, gates, fences, posts, hand rails, outdoor furniture and any situation where exposure to rain, moisture, insect pests and weather may promote degrade. CWP is also effective in areas where timber, although not directly exposed to weather, is subject to damp conditions with poor ventilation such as around wet areas in houses and under floors with low ground clearance. It must be stressed that use of a product such as CWP will generally not provide the same level of protection as pressure treatment. In most cases, with surface applied preservatives, periodical reapplication will be required.


CWP is ready to use, shake the can or stir contents briefly before use. Thinning should not be necessary.


Timber to be treated should be dry and clean. Any old paint, stain or surface moulds should be removed before application.


Recommended application method is by flood brushing, direct injection into affected areas or where convenient total dip or immersion for one or two minutes. For surface treatments the required absorption of CWP is 0.25 litres per square metre (1 litre per 4 square metres). One application may be sufficient in most cases. Allow at least 24 hours before a second application if it is required. Coverage will vary from approximately 4 to 8 square metres per litre depending on the timber species, moisture content, and surface condition. It is important that all surfaces are coated to ensure effective protection. All cutting, drilling, machining or planing should be done before treatment. Timber components should be treated before joining or fixing.

Remedial Treatment

For treatment of timber affected by insects (ie: pinhole borers, furniture beetles, drywood termite), drill damaged areas and inject the product. Treat all infested areas (as indicated by expulsion of frass) for maximum effect. A single application may be sufficient. Continued expulsion of frass may be due to movement of the timber. In severe cases timber replacement or use of a professional pest controller may be better options. After Application
Timber treated with CWP should be touch dry within a few hours of application. CWP may slightly darken some timbers. Clean up brushes and equipment with mineral turpentine.


In exposed exterior situations without the protection of additional paint or stains, reapplication is recommended after 6-12 months. Longer term protection will be obtained if the timber is coated with suitable exterior paint or stain (such as TWA Water Repellent). CWP should be re-applied as recommended as part of the re-application of the paint or stain.


Health and Safety

Wood preservatives are toxic and should be handled in accordance with the M.S.D.S. (Material Safety Data Sheet). Care should be taken to avoid contact with the skin, breathing of any vapour, contact with foodstuffs and oral ingestion. Personal hygiene should be observed at all times. The use of naked lights, smoking, etc. must be prohibited.



CWP is safe to use and will perform its intended function safely providing that the correct precautions are taken. A Safety Data Sheet is available on request if further information is required.

Handling The Product

Use impervious gloves (ie: PVC) and sensible work clothing when using the product and avoid breathing mist or vapour. When working overhead or where there is a risk of splashing wear glasses or other eye protection. CWP product and vapours may be combustible. DO NOT smoke or light any flame while using the product. Ensure adequate ventilation during use particularly if in enclosed spaces. Over exposure to solvent vapours may cause dizziness nausea and headaches. If these symptoms occur cease work and move to fresh air. In the unlikely event that the product is swallowed DO NOT induce vomiting. Give a glass of water and get immediate medical attention. After use wash hands and face with soap and water.

Environmental Considerations

The product is toxic to fish. DO NOT use where application drips or spillage will cause contamination of ponds streams or waterways. The product is toxic to bees. Do not use for treatment of bee hive boxes.


Caution, flammable liquid. Store in a secure place with the lid firmly closed and away from heat sources. Keep out of reach of children and keep lid closed when not in use.


UN 1306 Wood preservative Low Flash Point.


DO NOT dispose of the product down drains or into water courses. Absorb excess product onto sawdust or waste wood and bury. Crush empty containers and dispose of properly in accordance with local regulations.


CWP is available form your local stockist in 2 and 4 lt cans and 20 and 200lt (special order) drums


Preschem provides free technical advisory service on all aspects of timber preservation including the use of this product. Call us Toll Free now on 1800 641 711.

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