Welcome to part 2 of our series on wood types. This week I’ll be discussing oak & oak wood treatments. If you haven’t already read part 1, feel free to go check it out here: All about Pine Wood.
A Little History of Oak
Oak (or quercus as it is known in Latin) is a hardwood with some 400 known species. It has always been a popular wood in the UK, but in recent times it is even more widely used in construction and also as internal fixtures in clubs and gyms etc. For furniture construction, oak has become ever more the wood of choice, a trend expanding year on year since the year 2000 when China, India and Indonesia substantially increased their export markets. Pine has been the wood to suffer from oak’s popularity as it is more widely available in the Far East.
The flowers of many oak trees are known as catkins and they are produced by oaks when they reach their reproductive age, which is typically around 20 years. They are triggered by rising temperatures in spring. Ultimately it is the catkins of many oaks that turn into the acorns, so maybe that popular phrase… ‘mighty oaks from little acorns grow’ should be ‘mighty oaks from little catkins grow’, although it doesn’t quite have the same ring, does it?
Acorn of the mighty oak tree.
Treating Oak Wood
With regard to finishing and treating oak, there are numerous possibilities, but there are certain requirements that are asked for time and again… Often we are asked how external oak can be kept looking natural. Whilst the question is easy, the answer is not so straightforward. These are the necessary considerations:
- When water penetrates oak, it reacts with the high tannin content within oak, resulting in ‘blackening’.
- The sun’s UV rays will turn the oak to a silvery hue over time.
- Clear products are inevitably not completely clear, so they tend to ‘bring out’ the natural colours of the oak, normally making it a bit darker and warmer.
- The levels of rain, wind and sun will make a difference to how quickly the oak changes colour.
Oak turned grey/silver by UV rays & water damage.
Oak barrels traditionally used for whisky and beer.
If the requirement is to keep the oak looking as natural as possible, whilst preventing blackening or silvering as much as possible, then the following is the best system we know of:
- 1 coat of clear wood preservative
- Followed by 2 coats of Osmo UV Protection Oil 420 Extra
Osmo 420 Extra offers UV resistance and also contains biocide which is important for external timbers as it prevents the wood from becoming diseased with wet rot, dry rot and blue stone etc. The oil also repels water, thus preventing it from going black.
If the requirement is to protect the oak whilst keeping the silvery appearance, then the following is the best:
- 1 coat of clear wood preservative
- Followed by 3–5 coats of high-quality tung oil such as Morrells Tung Oil
Tung oil is one of the clearest oils on the market and doesn’t offer UV resistance.
If the exterior oak needs to be coloured, then the following system is recommended:
- 1 coat of clear wood preservative
- Followed by 1 coat of your chosen colour of Osmo Natural Oil Woodstain
- Followed by 1 coat of clear Osmo UV Protection Oil 420 Extra
If blackening on exterior oak needs removing, then scrubbing with a fungicidal wash such as Barrettine Mould and Mildew Cleaner is recommended. On the other hand, it may be the silvering that needs removing. If so, a scrub with Osmo Wood Reviver Gel (which contains oxalic acid, amongst other active ingredients) is recommended.
Unfinished oak.
Treated oak.
One of the most common enquiries we get is how to keep internal oak looking natural. This is not just a case of simply applying ‘clear products’ as they bring out the natural colours of the wood, thus making it a little darker and more golden. A very good indication of how your oak will look once it has been finished with a ‘clear’ coat is to dampen an area by applying some water with a clean cloth or sponge. The look achieved when the wood is damp/wet is very close to how it will look once a clear varnish or a clear oil has been applied.
Some customers like the way oak colours when clear coatings are applied to it, whilst others want it to be as close as possible to how it looks in its natural state. A more natural look can be achieved by using wood oils that have been specifically formulated to retain the natural appearance of interior oak. These products include:
- If an oiled finish is preferred, then apply two thin coats of Fiddes Hard Wax Oil Natural or Osmo Polyx Oil Raw.
- If a varnished finish is preferred, then 1 part Manns Classic Wood Dye can be mixed with 50 parts Manns Extra Tough Interior Varnish.
Clear wax polish is the one exception to the above… If a clear wax polish is applied to bare oak (or just about any other wood for that matter), then the colour is kept very natural indeed. It’s just a question of whether a wax polish is going to be durable enough. Internal doors, for example, are considered, by most people, to be ideal for finishing with wax, whereas a floor will look nice once waxed but regular maintenance is required, so most people don’t opt for wax for this reason.
If the oak needs to be made darker, then Osmo Polyx Oil Tints or Fiddes Hard Wax Oil Tints are ideal because they colour and protect the wood in the same application. It is always good to try and finish with a clear coat if possible because if the wood gets scratched, it is the clear coat that scratches before the coloured coat and therefore the scratch is not as noticeable.
Oiling Consideration
If oak is being oiled, it is a good idea to sand it with sandpaper that is no finer than 150 grit. The reason for this is that the pores of the wood are more open, thus allowing the oil to sink into the wood better. Better absorption equals greater protection.
Interesting Oak Stats
- Oak bark is rich in tannin and is used by tanners for tanning leather.
- Acorns can be used for making flour or they can be roasted for making acorn coffee.
- Tannin dissolves and escapes from the wood. Wine barrels are made from oak and it is the tannin that helps to give the wine its colour.
- Sessile oaks of Europe can reach heights of up to 40 metres.
- Oak trees regularly live to be 500 years old, although 1,000-year-old oaks are also known.
- A mature oak tree can produce up to 50,000 acorns!
Need help finishing a project made with oak?
For more help and advice on how best to finish oak, contact our team of resident experts who are always on hand to help with project advice and product recommendations.
We love to see before, during and after photos of any wood finishing project. If you would like to share your project pictures with us and our followers, you can either send us some photos or share on our Facebook, Twitter, Pinterest or Instagram pages.
469 comments
Hi,
I have just bought an interior oak dining table that we are putting outside in the garden. I want to know what to treat the table with to fully protect it, also tannin seems to be leaking from the table on to the patio, can I stop this?
I want the table to look as natural and pale as possible, are there any treatments that keep the wood like this as I hate the look of darker/yellow wood? Thankyou for your help :)
Reply to Siri:
Hello Siri,
Thank you for your inquiry, it is fair to say that tannin is in all woods and generally speaking the newer the wood ( in terms of when it was cut from the tree ) the more it will have and is more likely to leak out. But also sunshine and and moisture can cause the tannin to come out. You haven’t said that there is any product on the table currently so I will assume that it is bare wood and if that is the case then you should start by wiping over the wood with white spirit to clean and de grease. If there is any stains or marks as a result of the leakage you will need to sand these area back.
For the products that I would advise that you use , assuming the table is bare wood, a good preservative such as Barrettine Premier Wood Preservative (https://www.wood-finishes-direct.com/products/barrettine-premier-wood-preservative) this will protect against mould, mildew, rot and wood boring insects. It comes in a clear finish which may darken the wood very slightly, but more often than not will not alter the look. You will then need a top coat Oil based product such as Osmo UV Protection Oil Extra (https://www.wood-finishes-direct.com/products/osmo-uv-protection-oil) this will definitely darken the wood slightly as all Oils will do, but it is a clear finish that will enhance the finish of the wood. However if you are able to wait a little while then Osmo are bringing out a product that is designed to leave the wood looking as natural as if it has no product on, but still with a high level of protection. You should always do a test area to ensure that you like the finishes of these products. i hope this helps – Sam
Hi Sam,
Thank you very much. It looks like the current price of Decking Oils and Fiddes Oil is approximately the same price at the moment – in which case which would you better recommend?
Many thanks!
Hannah
Hello,
I am using some planed oak (European) to make a sort of shelf to sit on top of a wall in our garden (if you imagine something a bit like a window cill).
Is the best way of treating this wood to keep it looking natural for as long as possible (i.e. non silver and non-blackened) what you outline in the article, i.e. 1 coat of clear wood preservative followed by 2 coats of Osmo UV Protection oil 420 extra; or would there be something more suitable for wood which is inevitably going to have some water sitting on it (unlike a door where the water would more easily run off)?
In terms of colour choice, to keep it natural as possible should the oil be clear as well as the preservative?
And finally, how often would we need to re-treat it?
Many thanks
Hannah
Reply to Hannah:
Hello Hannah,
Osmo do not recommend using the Osmo UV Protection Oil Extra (https://www.wood-finishes-direct.com/products/osmo-uv-protection-oil) on a horizontal surfaces, although we have had customers who have done so successfully. You would probably be better considering a Decking Oils (https://www.wood-finishes-direct.com/collections/decking-oil) although many of these only come in a 5 Litre tins which may be too much for you. One other alternative would be the Fiddes Exterior High Build Wood Oil (https://www.wood-finishes-direct.com/products/fiddes-exterior-wood-oil) which comes in a 1 Litre tin if this is more appropriate. You are right to use the Preservative first and then finish with the Oil, they are all available in clear finishes but it is worth noting that any Oil will darken the wood slightly. Maintenance coats should only need to be done every couple of years ( dependent on use and extreme weather ) hope that this helps and if you have any further questions don’t hesitate to ask.
We are currently building a workshop store designed to have oak cladding and timber side hung double doors. The elevation gets the weather with rain and wind and full sun for most of the day. The cladding planned is European rough sawn feather edge oak which we would like to weather naturally to silver. Would you advise any kind of treatment given the south westerly elevation? Our other query is the doors which is planned to be European air dried oak (planed vertical panels) – we would like these to be in keeping with the cladding in terms of appearance and natural weathering. We have seen examples of similar buildings where the cladding has a natural appearance but the doors look golden/orange from a treatment and this is what we want to avoid. We would be grateful for any advice you can offer.
Regards
Reply to Chloe:
Good Morning Chloe,
There are two products that I would recommend for both your cladding and for the doors. The first is the Barrettine Premier Wood Preservative (https://www.wood-finishes-direct.com/products/barrettine-premier-wood-preservative) it comes in a clear finish and will protect your wood against mould, mildew, wet and dry rot and wood boring insects. Once this has dried I would recommend the top coat product you use is the Barrettine Log Cabin treatment (https://www.wood-finishes-direct.com/products/barrettine-log-cabin-treatment) as this doesn’t have the UV protection and so will allow the wood to silver naturally over time whilst still offering good quality weather resistance. These two products combined will give you a really good level of protection whilst still achieving the type of finish that you require. The doors may silver at a slightly different rate to the cladding due to the difference in the woods but inevitably both will reach that natural finish. And we would love to see some photos if you have time – many thanks Sam
Hello,
I bought a furniture set for our living room about 5 years ago which I believe is white oak with a natural waxed finish which I love. We have been looking to add a small sideboard to the room but unfortunately the company we originally bought our furniture from no longer exists. I have been looking for over a year to get a sideboard which matches the colour of the rest of our furniture and have in fact bought 2 or 3 but they are always too dark. I can’t find anywhere that does waxed light oak leaving it in its natural colour.
We have just bought another sideboard and again it’s too dark – I assume it has been varnished/oiled. I’m wondering if I can treat the wood to get it to a more similar colour to our old furnture? If I sanded it down would the natural wood be lighter in colour and then could I wax it?
Thank you for your help,
Sam
Reply to Sam:
Hello Sam,
Colour matching is such a difficult thing to do in our business, even with two woods the same such as Oak, there are so many factors that could make it difficult to get the colour you want. A tighter or looser grain will have an impact, where the wood came from and which part of the trunk the cut is from will all affect the final colour achieved when applying a stain or treatment.
Having said all that it is not entirely impossible, with a little bit of patience and experimentation, to get a very close match. Once stripped back to bare wood have a look at the Fiddes Supreme Wax Polish (https://www.wood-finishes-direct.com/products/fiddes-wax) first and see if there is a colour in that range that you could use. Or alternatively the Manns Classic Oak Stain (https://www.wood-finishes-direct.com/products/manns-oak-wood-stain) can be good to achieve the right colour. Remembering that a top coat product such as a Varnish or Oil will darken the stain as well.
Hi,
Great information on this site, thanks for sharing. We are looking at adding an oak cabinet to our existing oak kitchen. Our cabinets are 15+ years old and want to make sure everything comes together properly. We have been given lots of advise but it is contradicting. We matched our existing cabinet door in a show room to “natural oak”. The cabinet came in but is brown compared to my existing. We then discovered that the sample in the show room is aged and not what we were to expect. Cabinet manager tells me to wait 1-1.5 years and allow the cabinet to age naturally, other professionals tell me that they need to do a custom stain match and apply that. I want to go the right way, this is too expensive to just guess. I can send a picture of the colour difference if you would like to see.
Thanks
Jessica