Osmo UV Protection Oil Clear 410 & 420 Extra

All exterior woods grey naturally over time but Osmo's UV Protection Oil 410 and 420 have been developed to maintain and enhance the wood's natural colour whilst delaying the greying process by 12 times compared to untreated wood. Ideal for vertical joinery such as windows, doors, cladding etc, the natural oil based microporous finish does not crack, flake, peel or blister.

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£ 1.04 inc VAT

£ 0.87 (VAT excl.)

  • 410 Clear
  • 420 Clear Extra
*All Colours are a representation and may differ from the actual colour once applied.

Use Our Coverage Calculator


1 coat(s):

2 coat(s):

These figures are designed to give you an approximate guide only. Coverage can vary significantly depending on the condition and porosity of the substrate.

Product Description:

Osmo 410 and 420 Extra UV Protection oils are transparent, satin finish, oil-based protective wood finish for exterior wood. The 420 Extra contains a biocide to prevent the growth of algae, mildew and fungal attack whilst the 410 does not. The microporous surface allows the wood to breathe and reduces swelling and shrinkage and the water repellent surface does not crack, peel, flake or blister.

Please note that Osmo UV Protection Oils are also available with a light pigment; Spruce (424), Oak (425), Larch (426), Douglas Fir (427), Cedar (428) and Natural (429), please see the UV Protection Oil Tints listing for more details. Nb. The pigmented versions will always offer better UV protection than 410 or 420. As top coat on already coloured treated wood, Osmo UV-Protection-Oil extends intervals between renovations significantly.

As a self-priming finish, Osmo 410 & 420 prevent the greying process on vertical surfaces with a UV protection factor 12 in comparison to untreated wood when two coats are applied. The finish contains active ingredients that prevent mould, algae and fungal attack. Simply apply without sanding. Easy and seamless application. Finish stays workable while coating.

Recommended Use:

Osmo UV-Protection Oil is ideal for all vertical exterior wood surfaces: doors, windows, window shutters (dimensionally stable elements), carports, timber cladding, balconies, fences, pergolas, and summer houses (dimensionally unstable elements). Also suitable for bamboo poles (e.g. in screens). Nb.UV protection oil should not be applied directly to horizontal surfaces or surfaces with less than a 15° slope.


Based on natural plant oils (sunflower oil, soya oil, thistle oil and linseed oil), siccatives (drying agents) and additives, 420 biocidal active (no biocidal additive in the 410) ingredient: Propicona- zole. Dearomatized white spirit (benzene-free). This product fulfils EU regulations (2004/42/EC) according to the VOC content of max. 400 g/l (Cat. A/e (2010)). Detailed declaration of ingredients available upon re- quest.

Technical Data:

Specific gravity: 0.9-1.0 g/cm³
Viscosity: >50s DIN EN ISO 2431/3 mm, viscid
Odour: faint/mild, odourless after drying
Flash point: >60 °C acc. DIN EN ISO 2719


Up to 5 years and longer if can is kept dry and closed tightly. If thickened by frost, store for 24-36 hours at room temperature before use.

Surface Preparation:

Wood surface must be clean, dry and frost-free (moisture content max. 20%). UV-Protection-Oil Extra 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 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. Natural Oil Woodstain or Wood/Decking Oil.

For renovations, clean old microporous wood finishes thoroughly. Clean and refresh already greyed or weathered wood at the same time 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* 4001. 

*Use biocides safely. Always read label and product information before use.

Methods of Application:

Apply thinly along the wood grain with Osmo Natural Bristle Brush or Osmo Microfibre Roller and spread well.
Allow to dry for approx. 12 hours with good ventilation. Then apply the second coat.

Cleaning of Tools:

With Osmo Brush Cleaner (free of aromatic compounds) or white spirit.

Drying Time:

Approx. 12 hours (normal climatic conditions, 23°C/50 % rel. humidity). Lower temperatures and/or higher air humidity can increase the drying time. Allow for good ventilation while drying. Do not apply at temperatures below 5°C or when the temperature will drop below 5°C whilst it is drying.


1 litre covers approx. 18 m² with one coat.
Product coverage depends significantly on the character of the wood. All information refers to smooth and planed/cut surfaces. Other surfaces may lead to reduced coverage.

Please Note:

Oils enhance the natural tone of wood (similar to the appearance of wet timber), for this reason we always recommend doing a test area before the main application. Depending on the degree of weathering, apply one coat of Osmo UV-Protection-Oil Extra to the cleaned and intact finish after approx. 3-4 years.

For areas which are highly exposed to weather, such as weatherboard, post caps or window sills, please expect substantially shorter intervals between renovations. Vertical elements mounted onto horizontal wood should have at least a 15 degree angle. Sharp edges must be rounded (radius > 2 mm).

If the greying process has already begun, refresh the surface with Osmo Wood Reviver Power Gel and re-apply 2 coats of Osmo UV-Protection-Oil. To achieve the UV protection factor 12, it is necessary to apply 2 coats of UV-Protection-Oil Extra. With only one coat on untreated wood, the life of the finish is significantly shorter.

Due to the high oil content, clear UV-Protection-Oil Extra has a light yellowing effect when used as a finish on white substrates. Therefore as a top coat on white finished areas, we recommend Natural Oil Woodstain 900 White.

Osmo UV-Protection-Oil 420 Extra contains biocides and therefore is only to be used on exterior areas. The added active ingredients delay or minimize the risk of algae and fungal attack. For effective protection, two coats are to be carried out. In accordance with the latest technical research, a permanent protection against algae and fungal attack cannot be provided.


Keep out of the reach of children. Do not get in eyes, on skin, or on clothing. Contains 2-butanonoxime and propiconazole. May produce an allergic reaction. If medical advice is needed, have product container or label at hand. Use only outdoors or in a well-ventilated area. Harmful to aquatic life with long lasting effects. Avoid release to the environment. Dispose of contents/ container in accordance with chemical waste disposal regulations (AVV 08 01 11). Warning: Wash out any cloth used with this product immediately after use or store in an airtight container (danger of self-ignition). The dried finish is classified as B2 (normal flammability) according to DIN 4102 regulations. Safety data sheet upon request.


Dispose of leftover product and completely emptied packaging according to local official guidelines (waste code number 08 01 11). Only completely emptied cans can be recycled.


410 Clear Satin & 420 Clear Satin, with Biocide


5ml Sachet (420 only),125ml Tester Pot, 750ml, 2.5 Litre

The above mentioned information is provided to the best of our knowledge however without any liability.
  • Finish Satin
  • Area of Use Exterior only.
  • Anti-Slip No

01235 427000

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