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 sanded our tired white oak toilet seat back to its natural beauty. What finish would you recommend I use on it before fitting it back on the toilet? Thanks. Tom.
Reply to tom:
This is a really good question!
It does depend on the effect you are after, if you went with a clear finish it will make it slightly darker as if the wood has been wiped with a damp cloth whilst enhancing the natural colour of the wood.
With the toilet seat being in the bathroom where moisture could interfere with the wood I recommend first of all using Osmo Wood Protector 4006 (https://www.wood-finishes-direct.com/products/osmo-wood-protector). This is a base coat which works with the top coat to help protect against high moisture areas.
The top coat I would then suggest to use is Osmo Polyx Oil (https://www.wood-finishes-direct.com/products/osmo-polyx-oil). It’s a blend of natural oils and waxes which offers excellent durability and easy application over 2 coats.
The alternative approach would be to use a varnish such as. Manns Extra Tough Interior Varnish (https://www.wood-finishes-direct.com/products/manns-extra-tough-interior-varnish) this is a highly durable varnish that is quick and easy to apply. Varnishes are more durable than an oil but wood oils are easier to maintain and patch repair. We always recommend doing a test area before starting any project to test the product suitability and final finish.
If there is anything further that I can help with please do not hesitate to get in touch.
All the Best Samantha.
I am about to buy a secondhand oak coffee table that has been oiled, I want to return the oak to a lighter colour, how can I do this?
Reply to Tim Miller:
Hello Tim,
Thank you for getting in touch with your enquiry. Sanding back the wood will return it to its original colour and this is likely to be lighter than it is currently. Sand in the direction of the grain. Depending on how much oil is left on there you could start at an 80 or 100 grit to remove and the finish with 120 grit. Wipe the surface with a damp cloth to remove sanding dust.
Once you are back to bare wood, consider Fiddes Hard Wax Oil Natural (https://www.wood-finishes-direct.com/products/fiddes-hard-wax-oil-oak-lightening) or Osmo Polyx Oil Raw (3044) (https://www.wood-finishes-direct.com/products/osmo-polyx-oil-raw-3044). Both of these products are hard wearing and designed to retain the natural, light appearance of woods such as Oak. Always do a test area in an inconspicuous area before starting any project to test product suitability and final finish.
If you look at these products and have any questions, please feel free to contact us.
hello
i have made tankard out of solid oak should i treat it before use if so what with
dennis
Reply to dennis wallis:
Hello Dennis,
The wood may benefit from two thin coats of Osmo Wood Wax Finish Extra Thin (1101) (https://www.wood-finishes-direct.com/products/osmo-wood-wax-finish-extra-thin) to provide moisture repellency, although long term exposure to moisture could still mark or stain, the Osmo oil is very good at repelling most liquids and can help to prevent staining.
Apply two thin coats and wipe of any surface excess with a clean, lint free cloth in order to give this protection. The oil can be topped up as and when required with a thin maintenance coat, usually annually or when the surface starts to look dull, patchy or tired looking.
I hope that helps and if you have any questions or would like to share a photo with us please feel free to email us on wood@finishes.direct
All the Best Samantha.
Hi there,
We just installed a live edge oak mantel. The piece does not have the bark still on. One quarter of the live edge is a brown colour, while the other 3/4’s has started to gray due to weather. How can I make it a unified brown without losing the rough live edge of the oak and how do I get the browns in the wood to be enhanced without have a shine to it?
Thanks so much!
Reply to Renée:
Good Morning Renée,
You could have a look at the Osmo Wood Reviver Power Gel (https://www.wood-finishes-direct.com/products/osmo-wood-reviver). This product is designed to return the natural coloration of the wood. If the wood has been grey for a number of years it may require a second treatment. I would try a small test area first to see how it works on your Oak.
Once the wood has been treated with the Wood Reviver Gel, look at applying a Hardwax Oil such as Fiddes Hard Wax Oil (https://www.wood-finishes-direct.com/products/fiddes-hard-wax-oil) or Osmo Polyx Oil (https://www.wood-finishes-direct.com/products/osmo-polyx-oil). These protective wood oils will leave the wood looking and feeling very natural. It comes in a range of sheens including matt and has sample sizes to allow you to try a test area first.
If you take a look at those products and feel free to come back to me if you have any further questions.
Kind regards Samantha.
I have just brought some Oak untreated ready planed internal window sills. They are going in the front part of the house that faces south. I was like to keep the wooden looking natural, but don’t know which ofthe products to use. I would quite like to use a clear varnish & also protect from the uv rays, scratches etc.
Not sure want to use. Plus one is going into the bathroom which is constantly in use with the family.
What would you advise please?
Many thanks.
Tracy
Reply to Tracy Bellward:
Hello Tracy,
Thank you for getting in touch. We have some great, durable varnishes that can be used for your windows sills and one that I would recommend is the Manns Extra Tough Interior Varnish (https://www.wood-finishes-direct.com/products/manns-extra-tough-interior-varnish). It is durable and hard wearing but like most interior wood varnishes, will not offer UV protection.
Osmo Uviwax (https://www.wood-finishes-direct.com/products/osmo-uviwax) is an interior product that will help prevent UV damage to the wood, it is not as durable as a varnish but will provide protection to the wood.
For Bathrooms we often recommend the use of Osmo Wood Protector (https://www.wood-finishes-direct.com/products/osmo-wood-protector) to give wood extra protection from moisture and humidity changes. This can be used under the Osmo Uviwax but is not suitable for use as a base-coat under varnishes.
If you have a read up of those products and feel free to get back to me if you have any questions. Always try a test area first.
Kindest Regards Samantha.