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
Reply to Tessa:
Hi Tessa,
Naughty Husband! did the desk have any other treatment on it originally? If not then you could try wiping the surface down with a lint free cloth dampened with a quality white spirit such as Barrettine White Spirit (https://www.wood-finishes-direct.com/products/barrettine-white-spirit). This should dissolve the sunflower oil and enable you to wipe it off with an absorbent rag or towel. Lightly sanding the desk is an alternative but the whole desk will probably need to be done.
Carry out a test area first, if there is anything from the original state of the desk that you do not wish to remove then take care with the spirits. Or if you are unsure feel free to send me a photo to wood@finishes.direct and we can go from there.
All the Best Samantha.
I have built flower beds in the garden with upright and flat laying oak beams. They are untreated and I was surprised by how good the garden looks! They have been in over winter and are now turning gray and developing dark areas. Having put so much work in I’m now paranoid about the wood rotting and not lasting for the years and years I’m hoping to stay in the house.
Does anyone have any suggestions on whether or not I should perhaps pull back the soil and line the beds with plastic to keep the soil/moisture away from the wood.
And also am I write in thinking the best way to now treat the wood would be with a fungicidal wash, then perhaps a restorer to bring back some of the colour, then with a clear coat, then a uv protection? I’d love to upload a pic but I can t :(
Reply to Jamie:
Hello Jamie,
Its a common question and there is no right or wrong way to protect the wood, just giving the wood the best chance possible is is better than doing nothing at all. So a membrane will help for sure. Nearly all wood damage is the result of moisture ingress into the wood. This causes mould and mildew and long term it causes rot. The membrane will keep most moisture away from the wood surface, however can cause an issues if moisture gets trapped behind the membrane. This is likely to be far less than when there is direct contact with the soil however.
Also treating the wood with a wood preservative (https://www.wood-finishes-direct.com/collections/wood-preserver) will help to prevent mould mildew and rot. Soaking the ends in the preservative for an hour or two will ensure that the end grain is well protected. And a top coat of the Osmo UV Protection Oil Extra (https://www.wood-finishes-direct.com/products/osmo-uv-protection-oil) will help to protect against silvering and give extra water repellency to the exposed areas of the wood. This oil only requires very thin application.
Keep the oil topped up regularly will help to maintain the wood. I hope this helps and if you have any further questions or would like to send any photos the email address is wood@finishes.direct FAO Sam.
All the Best Samantha
I am restoring a garden bench. Cast iron ends have been media-blasted and painted. I have prepared oak slats/staves which have been sanded to 240 grit but can be ‘un-sanded’ to 120 if required! I want to retain the natural oak colour. I read your suggestion above but I don’t need a 5 litre clear wood preservative. What would you suggest I use that can be supplied in say 750ml? I will also use the Osmo uv oil as I love their products. Thanks, John
Reply to John:
Hello John,
The Osmo WR Basecoat (https://www.wood-finishes-direct.com/products/osmo-wr-base-coat) would be an ideal option for you. It is available in a 750 ml tin and will work well with the Osmo UV Protection Oil Extra (https://www.wood-finishes-direct.com/products/osmo-uv-protection-oil). If you take a look at the products and feel free to let me know if you have any other questions I can help with.
Kind Regards Samantha.
Hi
I have just had a brand new solid oak front door made. It obviously is in its raw state with no product yet applied. Can you tell me what I need to use to protect it? I have had new pvc oak windows fitted and would like the front door to blend with these.
Many thanks
Reply to Jess:
Hello Jess,
Thank you for getting in touch. I always recommend a wood preservative (https://www.wood-finishes-direct.com/collections/wood-preserver) first and we have a wide range of products to choose from. If you are looking for a clear natural finish then I would recommend a basecoat of Osmo WR Basecoat (https://www.wood-finishes-direct.com/products/osmo-wr-base-coat) to give additional water protection which also protects from mould, mildew and rot. And then a top coat of Osmo UV Protection Oil Extra (https://www.wood-finishes-direct.com/products/osmo-uv-protection-oil) to protect the door from the bleaching effects of UV rays from the Sun.
If you have a read up of these products and see if they are suitable for your needs. And if you have any further questions, I am here to help.
All the Best Samantha.
Hi Sam,
Thanks for great information centre, tho I admit I couldn’t find that I needed after reading 50 or so posts, so figured I’d just ask. We have had fitted 5 beautiful oak fire rated doors. However I have 3 clumsy and boisterous children and I would like to know how make the doors child proof! Kids prams, dinosaurs and lego wars I’m afraid are going to damage the doors. Can you recommend anything treat the doors with please. Also we have oak tread stairs, what would recommend do these? All new wood. Any help is greatly appreciated. Thanks, your namesake! Sam
Reply to Samantha Colyer:
Hi Sam,
I know that feeling, kids have a way of leaving fingerprints in the most unusual places. There are two options here and which one will depend on your needs. A varnish such as Manns Extra Tough Interior Varnish (https://www.wood-finishes-direct.com/products/manns-extra-tough-interior-varnish) will give a tough surface seal to the wood that will last longer and be easy to clean. If the seal breaks however it is difficult to patch repair and would need sanding back and re varnishing.
The alternative and still a very durable finish is Fiddes Hard Wax Oil (https://www.wood-finishes-direct.com/products/fiddes-hard-wax-oil) or Osmo Door Oil (3060) (https://www.wood-finishes-direct.com/products/osmo-door-oil). These wood oils soak into the surface of the wood and leaves it looking and feeling very natural. They are also easy to clean and maintain with the key benefit that any marks, scratches or stains that may occur can be easily patch repaired.
Both products have benefits and both will be suitable for interior doors and stairs. It’s worth watching some of our YouTube Video’s (https://www.youtube.com/channel/UC7-tgwbsUxm73aVnAjLGHRA) for product advice and application tips but feel free to come back to me if you have any further questions.
Kind Regards Samantha.
We have a piece of light oak furniture in the hall which has what I assume are water stains on the top and drawer fronts. I don’t know if it was oiled or waxed when we bought it. Is there any way of removing or covering the stains? I thought perhaps waxing would make the piece of furniture slightly darker and therefore make the stains less noticeable? Or perhaps oil would be better?