Osmo UV Protection Oil Extra (420 Clear)

Non Hazardous
Micro-porous protection against UV, mildew, algae and fungal attack on exterior oak or cladding.
Available in 0.75 and 2.5 Litres
From £23.69 £19.74
In stock
Only %1 left
Product Description

Osmo UV Protection Oil Extra (420 Clear) enhances the natural character of the wood while providing a satin finish that does not crack, peel or blister. Contains biocides to protect against algae, mildew and fungal attack.

Osmo UV Protection Oil Extra (420 Clear) provides a microporous surface allows the wood to breathe and reduces swelling and shrinkage. Osmo UV Protection Oil 420 provides a surface coating rather than a oil finish. If you require an oil finish, please look at the Osmo UV Protection Oil 410.

Water-repellent, does not crack, peel or flake. Simply apply without sanding. Easy and seamless application. Finish stays workable while coating. As top coat on already coloured treated wood,Osmo UV Protection Oil Extra (420 Clear) extends intervals between renovations significantly. As self-priming finish, it prevents the greying process on vertical surfaces with a UV protection factor 12 in comparison to untreated wood when two coats are applied.

Best Uses

Osmo UV Protection Oil Extra (420 Clear) is ideal for all exterior vertical wood surfaces: doors, windows, window shutters (dimensionally stable elements), carports, timber cladding, balconies, fences, pergolas, and summer houses (dimensionally unstable elements).

  • Incredibly water and dirt resistant
  • Reduces wood swelling and shrinkage
  • 420 contains biocides to prevent the growth of algae, mildew and fungal attack
  • Microporous, breathable finish which does not crack, peel, flake or blister
  • No sanding necessary for future applications


Wood surface must be clean, dry and frost-free (moisture content max. 20%). Osmo UV Protection Oil Extra (420 Clear) is ready to use, please do not thin. Stir well before use. Clean old microporous stains thoroughly. Old paints and lacquers must be completely removed. As a general rule, wear a dust mask during sanding works. Do not sand smooth surfaces finer than P120. If possible, please apply base coat to all sides before installation. Fresh wood, containing natural wood extractives and especially hard wood needs to weather off (for approximately 6 weeks) after installation. Thereby the wood becomes absorbent and the wood finish adheres optimally.

A base coat with a coloured finish is recommended, e.g. Osmo One Coat Only HS Plus, Osmo Natural Oil Woodstain or Osmo Country Colour. For renovations, clean old microporous wood finishes thoroughly. Already greyed or weathered wood should be refreshed and cleaned with Osmo Wood Reviver Power-Gel. The finished surface is, among other things, influenced by the wood‘s natural characteristics. Therefore, a trial application is always required, especially for unfamiliar surfaces. If additional protection against blue stain, rot and insects is desired, pre-treat the wood if possible on all sides with Osmo WR Base Coat. Use biocides safely. Always read label and product information before use.

Technical Details


  • As self-priming finish, it prevents the greying process on vertical surfaces with a UV protection factor 12 in comparison to untreated wood when two coats are applied


  • For ingredient rich wood species (such as Cedar, Iroko, Teak, Mahogany etc.) - please allow minimum 12 weeks exposure in situ to the outside elements prior to application.
  • Osmo UV Protection Oil Extra (420 Clear) is recommended only for vertically structured timber (drip angle min. 10º) to enable the rain to drip off rather than stay on the wood's surface for prolonged lengths of time.
  • Over application and/or low ventilation can increase the drying times.
  • The high-energy UV rays of the sun destroy the lignin in wood: it greys. Up to now, only wood finishes with colour pigments could possibly prevent this effect. With Osmo UV Protection Oil Extra (420 Clear), you have the possibility to protect your wood almost invisibly. Osmo UV Protection Oil (410 Clear) contains special ingredients that stall the greying effect by 12 times (UV factor 12). For a reliable UV protection, the wood finish must be applied more generously than other wood stains from Osmo.
  • Recommended application amount is approx. 55 ml per m2.
  • Oak contains a high acid content within its natural tannins and as a result causes the timber to blacken during exposure to cold and moist environments - especially during the winter periods. More frequent care and maintenance is required, particularly in its first couple of years of exposure to the elements, to maintain its decorative appearance.
  • Osmo UV Protection Oil 420 provides a surface coating rather than a oil finish. If you require an oil finish, please look at the Osmo UV Protection Oil 410.

Technical Info

Components: Single Pack
Type: Based on natural plant oils
Finish: Satin
Stock Colours: Clear
Tintable: No
VOC Content: 400 g/l
Odour: Faint/Mild
Suitable Substrates: All vertical wood surfaces in outdoor areas
Application Method: Osmo Flat Brush or Microfibre Roller
Theoretical Coverage: 1 litre covers approx. 18 m² with one coat
Application Temperature: Above 5°C
Touch Dry: Approx 12 hours at 23°C
Fully Cured: -
Cleaner / Thinner: Clean tools with Osmo Brush Cleaner
Shelf Life: Up to 5 years from date of production unopened
Packaging: Available in 0.75  and 2.5 Litres

The manufacturers data sheets are available for download from this website. It is your responsibility to read and understand all aspects of the data sheets before you place an order and prior to application. Please pay special attention to the preparation, mixing and application temperatures of the product, cleaning of substrate and environmental factors such as temperature, rain etc. Quoted coverage rates are based on the manufacturers theoretical rates and may vary depending upon substrates absorption, texture and application. We always recommend a test is carried out to ensure suitability.

Customer further agrees that Promain have no liability for any errors or omissions contained within the Product Data Sheets and are not liable for failure due to misapplication or inadequate substrate cleaning and preparation. For more information please refer to our Terms & Conditions.

Recommended products to use