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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 mohair 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 the Osmo Natural Oil Wood Stain colour range.

  • 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 mohair 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 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, Garapa and Meranti?

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 158 reviews.

Filter:   All reviews (158)   5 stars (129)   4 stars (26)   3 stars (2)   1 star (1)  

David Gunn

 750ml, Oak - 425 Extra
A great product which with the Oak transparent finish gives great depth and colour to woodwork.
Having previously used the clear semi-matt version I needed a bit more colour to my natural wood window frames. Moreover, I knew it would cover-up those minor blemishes so I decided to try the Oak transparent finish. I was very pleased with the results and the oil goes on so easily and economically.
James Forsyth

 2.5L, Clear - 420 Extra
Simply fantastic
I used this product on some solid oak timber doors and windows and I loved it.Very easy to use and really bought back the natural beauty of the wood.one of the best products I have used in many years of decorating
Justin Ziegler

 2.5L, Clear - 420 Extra
Great product
Great treatment for our doors & windows, keeps the woods natural colour. Easy to apply. Used for years and our doors and windows still look like new. Two or three coats once every two years, worth the effort.
Elizabeth Farley

 2.5L, Clear - 420 Extra
Excellent product and service thankyou
Osmo gives a very durable, impressive finish to our oak building, Ordering and delivery were spot on and the price fair compared to competitors. Building has received numerous positive comments.
Martyn Johnson

 2.5L, Clear - 420 Extra
Well-known product. Don't know how it will perform over a long period, but it has a good reputation.
Alan Collings

 2.5L, Oak - 425 Extra
It is extremely good stuff
I'm going to cut the rubbish and advise people that this oil is the real stuff and does exactly has it says on the tin. yes it is quite dear to buy , but quality costs.
Dan Winzar

 2.5L, Clear - 420 Extra
Used before so knew product would leave a good finish and protect oak well
Good tracking delivery service and prompt despatch. Arrived when promised. No complaints at all, overall very pleased!
Lauren Godfrey

 2.5L, Clear - 420 Extra
Worth every penny
This is good stuff and had been recommended by people in the trade. Wood finishes direct were fantastic from start to finish.Excellent customer service.
Grace Blackmore

 2.5L, Oak - 425 Extra
Covers well, good matching colour on existing oak windows/doors
Seemed to be the most well rated and professional product for use on our windows and doors at home. Product is a good consistency and is a very good colour match to the existing oak. We have just done one coat so far and it has improved the look of the timber, and feels like a quality product that has absorbed properly and that will last. We didn't know when the windows were last treated (previous owner) so have been generously applying, and product seems to go quite far and dries well and quickly.
Ram Chauhan

 750ml, Oak - 425 Extra
Looks great on the outside door
I bought this on recommendation from mt decorator. He said he only uses this product for any outdoor hardwood finish as varnish does not tend to be resistant to sunlight. Looks good so far....onlt time will tell if it is affected by sunlight
John Emery

 2.5L, Oak - 425 Extra
Easy and professional finish
I used this oil for my redwood fence panels. It was very easy to apply (thin thin coats) and looks fantastic. It has rained since and it's great to see water beading away! Very highly recommended - should only need a one coat top up every few years. I would suggest buying the brush cleaner from Osmo - I didn't and regretted it. I couldn't get the oil out of the brush so I left it overnight in water until I was ready to apply the second coat! It worked.... Will definitely buy again and from woodfinishesdirect.com as the service and cost were exceptional.
Evelyn Jefferies

 2.5L, Clear - 420 Extra
Easy to apply, leaves a nice finish
Easy to apply and went a long way. A decorator friend says it's 'the best' and I can't disagree. The rain was just bubbles on top of the wood, even though we'd only oiled the summerhouse the day before.
Mr Humber

 2.5L, Clear - 420 Extra
Awesome product definitely recommended
Great product, easy to apply and you can see the wood return to its natural and beautiful state. Highly recommended.
S Green

 750ml, Clear - 420 Extra
Expensive , but good
Higher price but excellent rain repellent so far. Only time will tell if it's got pedigree!
Mark McCarthy

 750ml, Clear - 420 Extra
Excellent product
I used Osmo 420 UV protection oil on a new solid oak garden gate. I applied two coats. After the first coat was dry I sanded it with fine 240 grit paper and applied the second coat. It dried to a lovely satin finish and looks well protected. I will definitely use this product again and would highly reccomend it.
Robert Mcleod

 750ml, Clear - 420 Extra
Osmo UV oil was easy to apply by brush, coverage was not as good as suggested on tin and drying time approximately twice as long.
Overall very satisfied with Osmo UV oil although it is too soon to gauge its efficacy. Oil was easy to apply by brush, although coverage was quite a bit less than suggested on tin. Note the drying time was also much longer in my case, still tacky in some areas after 5 days. Buffing off excess immediately with a lint free cloth would almost certainly improve this situation however.
Olivia Stephens

 2.5L, Clear - 420 Extra
Gives the wood a lovely depth of colour
This product had already been used on our garage windows and doors and we liked the finish. It gives the wood a lovely golden colour, it's come up a treat! We have used twice as much as the expected amount which has been a bit costly but I think this is because the wood is rough sawn and so more has soaked in - this will hopefully give the wood extra protection. We've also been applying it on lovely sunny days so the wood is really dry.
Barry Lambe

 2.5L, Clear - 420 Extra
A very large oak gate. after 2 days sanding and cleaning 2 coats applied. a great finish.
Anthony Mitton

 750ml, Clear - 420 Extra
An excellent product which enhances and protects the natural finish of my oak conservatory
I recently had an air dried oak conservatory installed and on Wood Finishes Direct recommendation, I applied one coat of Wood Preservative followed by two coats of Osma UV Protection Oil. The result is everything I'd hoped for and the UV Oil has given a wonderful satin finish which enhances the natural appearance of the oak. A perfect choice and well satisfied!
Paul Lynch

 2.5L, Oak - 425 Extra
Excellent product at a good price with fast free delivery.
Bought to provide protection on oak fascia boards for a new house. Fairly easy to apply and providing a really nice finish after 2 coats.

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

Coverage Calculator

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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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