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Osmo UV Protection Oil Extra

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Osmo UV Protection Oil Extra is a superior wood oil that protects timber against the greying effect of the Sun's UV rays by a factor of 12. It offers superb durability against weathering with an added biocide to combat insect attack and fungal growth.

Easily applied with a paint brush or velour roller Osmo UV Protection Oil Extra dries to a satin-matt finish that will not peel, flake or blister.

Can also be used for lightening or overcoating Osmo Natural Oil Wood Stain colours. Also available Osmo UV Protection Oil Extra Natural which helps retain the untreated appearance of timber.

  • Prices
  • Overview

Osmo 420 & 425 Overview

Perfect for use on all exterior timber including external doors, window frames, windowsills, carports, timber cladding, balcony, screens & fences, pergolas, garden houses, furniture and more.

Osmo UV Protection Oil Extra has been designed to combat the greying effects of the Sun's UV rays on exterior wood. Can be applied to a wide range of exterior soft and hard woods including Pine, Larch, Teak, Oak and Bamboo.

Exterior timbers turn grey or silver over time as a result of exposure to the sun and rain. Osmo UV oil acts as a 'sun cream for wood' slowing the greying process by a factor of 12 when compared to untreated wood.

Osmo 420 Extra and Osmo UV Protection Oil 425 Oak also contain Biocide which helps to protect timber from the onset of mould, algae and insect attack.

These UV Oils are micro-porous, thus allowing the wood to breathe. As the oil penetrates into the surface of the timber, it doesn't form a surface coating, so will not crack, peel, flake or blister. Osmo 420 clear and 425 Oak penetrate deep into the grain aiding the natural elasticity of the wood and helping to reduce shrinkage and swelling.

Osmo 420 clear & 425 Oak - Key Features

  • Based on natural, renewable resources
  • Final finish protects against mould, algae and fungai attack
  • Oiled finish provides a microporous, breathable surface
  • Foundation and top coat in one
  • For use on dimensionally/non dimensionally stable exterior wood
  • Dries in approximately 12 hours under normal conditions
  • 2.5Ltrs tin covers approximately 45 square meters based on 1 coat


Ensure surfaces to be oiled are clean, dry and free from all surface coatings such as paint or varnish before application. Wood that has been previously oiled should be cleaned and lightly sanded.

New unpreserved or old wood should first be treated with a quality wood preservative such as Barrettine Wood Preservative or Ronseal Total Wood Preservative before applying Osmo UV Protection Oil. Using a wood preserver prior to applying the oil gives additional protection against mould, algae, dry rot, woodworm and other wood boring insects. Allow sufficient time for the preservative to dry, normally 24 to 48 hours, before applying 'Osmo 420 Clear' or 'Osmo 425 Oak'.

As an alternative to spirit based preservatives Osmo WR Base Coat 4005 can be used. This product penetrates deeply into the wood to help repel water and moisture. This helps to reduce the risk of timber swelling and shrinking therefore reducing the chance of the wood cracking, splitting and warping. Note: this product does not contain an active insecticide.


Apply in thin coats with a paint brush or velour roller ensuring that the oil is worked into the grain of the wood as opposed to painted on top of the wood. Always finish your brush or roller strokes by going in the direction of the wood grain. Osmo UV Protection Oil Extra 420 can also be applied over Osmo Natural Oil Woodstain as a top coat for added protection and durability.


Slightly tired looking areas can be easily refreshed by simply cleaning the affected areas and applying a fresh coat of Osmo UV Oil. Even badly scratched areas can be seamlessly repaired with a light sanding and a re-application of the oil.

Equipment Cleaning

Application brushes and other equipment should be cleaned with Osmo Brush Cleaner or White Spirit.


Osmo UV Protection Oil Extra has a shelf life of 5 years or more if kept sealed in the original tin. Store in a dry cool place. If thickened by cool temperatures or frost, the oil will regain its normal consistency within 24 to 36 hours of being returned to normal temperatures.

To preserve any remaining oil once the tin has been opened and used, decant any remaining oil into a smaller tin, jar or container, fill to the rim and seal with an air tight lid.


Osmo recommends that this product is NOT used on horizontal surfaces where water can collect such as floors, decking and wooden steps etc.


Q. We have a garden table which says only use Roble Wax and not Linseed Oil. I have searched for this product and even with the Internet I have not succeeded. The table was from B&Q. Please can you help me?

A. To my knowledge, it's only B&Q that offers the Roble garden furniture in The UK and the product recommended for finishing it is indeed hard to find. We have looked into this thoroughly and can confirm that Osmo's UV Protection Oil is ideal for Roble wood. As Roble is a dense, oily wood it is important to work the oil into the wood well and apply it thinly.

Q. I work for a joinery that makes and fits bespoke hardwood windows, doors and decking. Can Osmo UV Protection Oil be used on dense exotic hardwoods like Teak, Iroko, Ipe, Meranti and Garapa?

A. On the tin it states that Osmo UV Protection Oil Extra is not suitable for use on Iroko, Teak and other exotic hardwood timbers but we have customers that have used Osmo UV Protection Oil with success on these woods.

Lightly sanding with a 120 grit sandpaper helps to open the tighter, less porous grain of exotic hardwoods enabling the oil to penetrate easier. Wiping the timber down with methylated spirit prior to applying Osmo UV Oil can help to remove some of the natural oil from the surface of the wood which helps the Osmo Oil to penetrate. Ensure the oil is at a good room temperature as it thickens when cooler making application more difficult. Apply thinly working the oil into the surface grain of the wood.

Q. Can Osmo UV Protection Oil 420 Clear be used on garden decking?

A. Osmo says that this product isn't suitable for use on horizontal surfaces such as decking. This said however, we have customers that have applied one coat of Osmo Decking Oil then applied 2 very thin coats of Osmo 420 clear on top and have been happy with the results.

Drying Time

Osmo UV Protection wood oil dries in approximately 12 hours in normal climatic conditions of 23℃ / 50% relative humidity. Lower temperatures and higher humidity can increase the drying time.

  • Reviews

Osmo UV Protection Oil Extra reviews - Rating: 4.8 out of 5 stars, based on 228 reviews.

Filter:   All reviews (228)   5 stars (192)   4 stars (32)   3 stars (2)   2 stars (1)   1 star (1)  

Tony Westcott
 2.5L, Clear - 420 Extra
Excellent product
Gives a very transparent finish to wood without darkening or yellowing effects; very good coverage. Wortrh paying a bit extra for.
Lorraine Johnstone
 2.5L, Cedar - 428 Extra
Very strong colour
thye ceadr colour is very strong - rather like putting fake tan on the fence. We had previously used the clear Osmo UVP rotection oil but after 12months the colour on the south facing fence was starting to fade. Have now applied the cedar coloured product but the colour is too strong (hopefully it will fade). Next time I will try and mix clar:cedar 50:50
Our feedback:-

I'm sorry that you weren't happy with the colour. I would recommend mixing the clear and the cedar if you want to acheive a lighter colour.
Derrick Conway
 750ml, Oak - 425 Extra
Good finish
Used this oil on oak after first applying Barrettine wood preservitive. The oil finish now looks brilliant
 2.5L, Clear - 420 Extra
I have put two coats of oil on our new oak garage doors and the colour has been lifted. They look absolutely beautiful.
Stella Swindell
 125ml, Clear - 420 Extra
Enhances oak beautifully.
Used this to protect the wooden oak frame surrounding my door and porch. Following the advice onsite, I used base coat of Barrentine's wood preservative first. I found the oil very easy to apply, using a small mako brush. I doubted the 125ml tin can would do the job, but It spread well and I managed to do 2 coats with some over. The oak looks beautiful and I am very pleased . Neighbours have commented on how good it looks- not bad for 80 year old wood!
Chris Davies
 2.5L, Clear - 420 Extra
OSMO oil is amazing
The best finish I have ever used on wood! I have an oak framed house and this stuff is fantastic!
F Hammond
 2.5L, Clear - 420 Extra
Easy to apply with great results!
Easy to apply with great results!
David Stedman
 750ml, Clear - 420 Extra
Easy to use
Used over Barrettine Premier Clear Preservative. As with the preservative it was easy to apply and the water just runs of the surface. So far so good!
G Saunders
 2.5L, Clear - 420 Extra
Certainly appears to perform as it should. The wood looks great.
Scott Keetley
 2.5L, Clear - 420 Extra
Brilliant stuff. Does exactly what it says on the tin....
Brings the grain out lovely. Used it on all my oak doors. Brilliant stuff...
Daniel Varga
 2.5L, Oak - 425 Extra
Excellent product
Excellent product. Best you can get for your outdoor hardwood furniture.
Chris McCall
 2.5L, Clear - 420 Extra
Excellent product
Very easy to apply, covers a large area relative to the amount used and leaves a lovely finish on the wood.
Ian Barrett
 750ml, Oak - 425 Extra
Great Finish
Used on Oak garden furniture covers very well and goes a long way
Andrew Major
 2.5L, Oak - 425 Extra
Lovely warm colour, which enhances the grain.
Great product as always from Osmo, went on well and leaves a lovely rich warm colour. Wood finish direct gave the best price, with fast delivery and excellent customer service.
J Ewen Macgregor
 125ml, Clear - 420 Extra
Very good.
Very good. But be careful of time taken to dry if cold and /or humid. Only time will reveal how good.
Ian Tearle
 2.5L, Clear - 420 Extra
Quality finish at an excellent price
Used on garden trellis with pleasing results
Martin Stoner
 2.5L, Clear - 420 Extra
Excellent Product
Quality product with a quality finish, I used this along with the WR Base Coat on 3 new oak doors. Fantastic protection and finish soaks in well and brings the grain out. Will always use Osmo.
Kath Kibble
 2.5L, Clear - 420 Extra
I used Osmo oil when I first laid my oak floor, its so easy to apply and so natural. It leaves no residue like Varnish and when its time to revive the floor its simple no sanding just clean it and apply. I revive my floor every 2 years, it lifts it and looks amazing. The real beauty of Osmo oil is that you can touch up any areas you have missed when dry it blends in perfectly.
G Biggins
 2.5L, Clear - 420 Extra
Easy to use , on planed wood covers easily, but on sawn wood coverage was a lot less
John Brixton
 2.5L, Clear - 420 Extra
Go's on nice and easy
Best product you can buy for oak

per litre
12 hours
dry time
  • Protects against greying
  • UV-Protection factor 12
  • Will not peel or flake

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* Coverage can vary depending upon on the type of wood used and the amount of product applied. Litreage amounts shown above are total, not 'per coat' amounts.
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