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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. Available in clear or as two attractive colours, Cedar and Oak. 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.

Please be advised that 125ml tins are printed in German only. For application instructions refer to the overview below.

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  • Overview

Osmo UV Protection Oil Overview

Osmo UV Protection Oil is available in clear (420) or coloured / pigmented variations including Cedar (428) and Oak (425).

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 UV Protection Oil 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 272 reviews.

Filter:   All reviews (272)   5 stars (221)   4 stars (44)   3 stars (5)   2 stars (1)   1 star (1)  

Chris Winfield
 2.5L, Clear - 420 Extra
Should be good
I have used OSMO products before and they are excellent. I haven't yet used this one. The key will be how well it weathers.
Matt Haynes
 750ml, Clear - 420 Extra
Great service after initial problem customers services called back and went the extra mile!
Great product used for red cedar office and gates eay to use looks great leave to dry overnight before second coat.
Antony Poulton
 2.5L, Clear - 420 Extra
Easy to apply and did the job
We wanted to retain the colour of our western red cedar cladding and after using a sample from Wood Finishes Direct of the clear UV Protection oil I decided that this was the best option. 1 tin covered a new extension that we had build this year and it looks brilliant - brightens the colour and repels water well. I hope it lasts!
Brent Buskell
 125ml, Clear - 420 Extra
Looks Good !
I can't really say if this product does what they say, because it should protect the timber over a long period and I've only just applied it to the door! It does look smart though !
Wendy Green
 750ml, Oak - 425 Extra
Excellent product and service
I have previously used Danish oil on my exterior oak doors getting terrible blistering and peeling every year. I have used Osmo oil on an oak floor inside with excellent results, so tried Osmo Exterior. I chose the oak oil as the doors had gained a mottled effect with the flaking danish oil. The result is excellent. Lovely colour and sheen and mottling disguised. Now just hope it lasts. NB The oil was colder when I did the 2nd door so was harder to apply and longer to dry. So make sure you store the oil in the warm if using through autumn/winter.
Jon Durkin
 750ml, Clear - 420 Extra
Good product
Goes on well took a long time to dry but then again it has been cold. Put on cedar and it's brought the colour out beautifully.
Tim Walls
 750ml, Oak - 425 Extra
Took a very long time to dry
Took forever to dry after the first coat - still not completely dry after a week even though it had been brought indoors and only had a thin coat applied. Second coat much better
Our feedback:-
Hello Tim,

Very thin application of this product is vital, it can almost seem like you are removing the product when working in or wiping away excess, but thin application soaking into the wood should dry within 24 hours.

Another factor that could have prolonged it, is the temperature or moisture in the air. Cooler temperatures at this time of year can slow down the drying process.

Kind Regards Sam.
Amanda Goddard
 750ml, Clear - 420 Extra
Does what it says on the tin
Easy and pleasant to use. Used it two years ago on brand new pine window frames. Most windows are still looking good. The most exposed now need redoing but they have been through one of the wettest winters in memory. Probably we should have used some sort of base coat or sealant - check the website for this, as it doesn't tell you this on the tin.
Alan Jackson
 2.5L, Clear - 420 Extra
Used it before. Brilliant
This product was recommended to me by my niece's husband who is a time-served carpenter. It's great.
Christopher Denney
 2.5L, Clear - 420 Extra
Dos exactly what we wanted
Excellent delivery time. Good quality product. You get what you pay for.
 2.5L, Clear - 420 Extra
First class
I've used water based products on wood before and they quickly fade and need redoing. The Osmo Oil Extra gives timber a solid and firm protection that will last for a long time. It's by far the best wood treatment I've ever used and you can tell the difference when it's raining and the water runs off the protected surface. Well worth the extra cost.
 2.5L, Clear - 420 Extra
Excellent protection
Easy to apply and keeps my oak beams looking smart. I like to give my exposed beams a quick rub down and re-coat each year.
Mary Newbold
 2.5L, Clear - 420 Extra
Great product always gives consistent results
We've used this product for the last 2 years on our hardwood gates. The finish is good, and application is simple always gives good results
Gerald Peach
 2.5L, Oak - 425 Extra
Once you have done a light sanding a doddle to apply.
Once used you will find it extremely difficult to fault. Used on gates open to the elements, 10 mins from sea, so a real test, I would personalley endorse this product to anybody, D.I.Y or professional.
Vicky Turnbull
 2.5L, Clear - 420 Extra
Great product
Oil does exactly as expected. Good product, easy to apply.
Ray Grigg
 2.5L, Clear - 420 Extra
A great product, easy to apply with a fantastic finish.
David Hall
 2.5L, Clear - 420 Extra
Does what it say's on the tin.
I have used it before apply brush or roller. Sand lightly between coats. I put on three coats should last a few years before it needs recoating.
Andrew Taylor
 2.5L, Clear - 420 Extra
Touch ups necessary after 10 months...
I write this review having ordered another tin (after a previous 3) of this oil as I have had to do a number of touch ups on my new pine log garage after less than 10 months. My garage had 2 coats or preservative followed by 2 coats of the Osmo UV 420 Clear Extra oil. Overall the garage still looks great but I am unimpressed I am having to touch up again so quickly, especially given the expense of this oil. I've bought another tin in the hope its just because these parts of the wood needed 'a little extra' on the sides that get more sun and that it won't be a constant battle. If however I'm having to re-do the entire garage again next year then I will have wished I'd have stuck with the average cuprinol stuff at less than half the price! Oh yes and don't expect it to last long on horizontal surfaces - it doesn't! I've put it down as 'no I won't buy again' but thats primarily as I am somewhat neutral at this stage but feel a little let down by the product...
Our feedback:-
Hello Mr Taylor

It is fair to say that areas that get more sun than others will potentually silver quicker and need maintenance sooner rather than later, however. This is also true of areas effected by extreme weather throught the winter.

However 10 months does seem a little soon to be having to top up the Oil. Can I ask if there was any previous treatent on the wood? Would you be able to send some photos to wood@finishes.direct so that we can take a look and help to resolve this issue for you.

Kind regards Sam.
Diane Staphnill
 750ml, Clear - 420 Extra
Excellent product
Used this to add a protective top coat to a huge wooden bear sculpture which had already been treated with different shades of brown oil by the sculptor. Excellent coverage and the rain just runs off.
Oliver Charlesworth
 750ml, Oak - 425 Extra
Very easy to apply, works well and looks great
Did exactly what we needed. Really liked the summary of how to treat Oak on the website and what products (in which order) are required for the different looks. Bought in conjunction with a preservative. The door looks amazing now after 2 coats. The water beads up and it's like new again.

per litre
12 hrs
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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