Products such as Manns Premier Door Oil, Osmo Door Oil (3060) and Fiddes Door Oil have been specially designed for use on veneered internal doors. It gives interior doors a tough, durable, clear, satin finish. Always check the door manufacturer's guidance before treating veneered doors as in some cases, it may invalidate the warranty of the door.
In our opinion, wood oils are one of the best options for wooden interior doors. They nourish the wood and prevent the door from drying out therefore protecting the door from shrinkage, splitting and warping. An oil finish is also very easy to maintain and repair if it becomes dirty, scuffed or scratched.
This can depend on the colour and type of finish that's desired. Wood stains such as Manns Classic Pine Stain are a great way to stain interior doors as they offer the widest range of colours and can often be intermixed (from the same product range) to achieve many thousands of wood tones and shades. Water-based and solvent-based liquid stains must be over-coated and sealed into the wood with a clear wood oil, varnish or wax. There are a wide range of pigmented or coloured wood oils, varnishes and waxes that both colour and seal the wood in one which are also ideal for interior doors.
If doors have been previously oiled or waxed, there's a good chance that paint will not effectively bond or adhere to the door surface. This could result in paint simply peeling off or in the case of water-based paints, simply running or dripping off the door surface. Our advice would be to get the doors professionally stripped. It is possible to remove the old finish by sanding or using a wax and polish remover but this could be time consuming and messy.
Interior Oak veneer doors can be treated with either a wax, oil or varnish. Using a clear door oil or varnish will enhance the natural grain and character of the wood, they will also slightly darken the wood to give it an almost damp-like appearance. Using a clear wax such as Fiddes Supreme Wax Polish will keep Oak veneered doors looking natural but offer less protection than oils and varnishes against scratches and scuffs.
For durability, varnishes offer the best protection. For ease of maintenance and repair from minor scratches, scuffs and scrapes, we recommend using a door oil or wax. Always check with the door manufacturer's guidance before applying a finish to a door.
The colour of Meranti can vary from pale-red to a darker reddish brown. Applying a clear oil will enhance the natural colour and character of the wood but will also darken it slightly, giving an almost damp-like appearance. A way to test how the doors may look with an oil or varnish is to dampen a section with a clean sponge dampened with water. If this colour is desirable, Osmo Wood Wax Finish Extra Thin (1101) is perfect for protecting hardwoods, such as Meranti as it is thinner and can penetrate deeply into the tighter grain, whilst still giving a high level of protection from dirt, scuffs and abrasions.
Oils such as Osmo Polyx Oil Raw (3044) and Fiddes Hard Wax Oil Natural are perfect for lighter species of hardwoods such as Oak and will keep the wood looking as natural as possible, whilst still offering protection from moisture, fingerprints and knocks.
It is very important to do a test area when considering these products and especially so with darker shades of Meranti, Walnut and other hardwoods as these oils will often leave a slightly milky looking finish.
Applying a clear oil or varnish will likely darken the wood and enhance the natural grain and character of the timber. This can be tested by wiping over a section of the freshly stripped doors with a clean sponge dampened with water. How the wood looks when damp is a good indication of how they will look with a clear oil or varnish.
To retain the natural untreated look of the wood, either a clear wax or specialist wood oil will work. Wood waxes are easy to apply, maintain and repair but offer little resistance to liquid stains, scuffs and scratches. Oils such as Osmo Polyx Oil Raw (3044) and Fiddes Hard Wax Oil Natural are again easy to apply, maintain and repair but offer much better protection whilst better retaining the natural, untreated appearance of the wood.
Doors can be varnished at any time prior to hanging if they have been given enough time to fully dry as per the manufacturers specified drying time on the packaging. It's worth mentioning that although most varnishes only require a matter of hours to dry, the full curing or hardening time can in fact be days, sometimes as much as 5 to 7 days to achieve full hardness. If doors can be varnished and allowed to dry for longer then there is potentially less risk of them being scratched or damaged during hanging.
The amount of product required to treat a door can vary on the type of product being used. All of our product pages have a coverage calculater which gives an estimation of how much product is required based on a given area. This calculation is only an estimate as the actual amount depends on the type and condition of the wood.
In terms of doors, we usually say to allow 3.5 square meters per door which allows for the treatment of both sides. As an example, 5 interior doors would require enough product to cover approximately 17.5 square meters (3.5 x 5).
With venerred doors, it's always important to check with the door manufacturer as to which type of product is suitable i.e. a wax, oil or varnish? Some manufacturers may stipulate one type of finish over another and warn that some finishes should not be used. In our experience, we have never had an issue with any product being used on a veneered door, but using one that is not recommended will likely invalidate any warranty on the door.
The best products for retaining the natural, untreated look of the wood are clear waxes or specially formulated hardwax oils. Waxes offer limited protection and are easily scuffed, stained and marked. This said, waxes are easily applied, maintained and repaired if an area does become worn or damaged. An alternative to clear waxes are hard wax oils, specifically Fiddes Hard Wax Oil Natural and Osmo Polyx Oil Raw (3044). These products are designed to better retain the natural, untreated look of the wood whilst providing excellent durability and protection against stains, scuffs, scratches, liquid spillages and more. They are also easy to apply, maintain and patch repair if required.
It's common for door manufacturers or suppliers to only recommend their own door finishing products such as an own brand varnish, oil or wax. In reality, these are just white label products that they brand as their own meaning that other similar products will be fine which in this case, would be other water-based varnishes.
It's also common for many door manufacturers to recommend that you don't use certain types of products such as wood oils or waxes. In our experience we have never encountered an issue with anyone using these products on Oak veneered doors. Using non recommended products however will likely invalidate any warranty on the door so it's always worth double checking with the door manufacturer or supplier before treating doors with alternative products.
The black spotting is likely mould spores in the timber that have started to react with moisture and the tannin in the Oak. Before refinishing the door it's important to treat and kill any mould spores with a mould and mildew remover such as Barrettine Mould and Mildew Cleaner. This will clean the black spotting from the wood and kill the spores within the fibres of the wood. Once this has been done, we recommend that the door is treated with a wood preservative such as Barrettine Premier Universal Preserver. When this has fully dried, usually 48 hours, the door can be treated with a suitable exterior wood finish.
If the door is to be oiled, we recommend using Osmo WR Base Coat (4001), an excellent water repellent base-coat followed by 2 thin coats of Osmo UV Protection Oil Extra, a clear exterior wood oil that contains biocides to protect against mould, algae and fungal attack. It also contains UV filters to protect the wood from the Suns UV rays.
If the door is to be painted or varnished, this can be done once the wood preservative has fully dried.
Using a wood oil will retain the appearance of the Oak, is easy to apply and maintain and will never crack, peel or flake off.
If there is space to treat or paint doors prior to hanging then it can be beneficial to do so. Having doors laying flat on some sort of work benches or platform means that there's no stretching or bending to reach all areas. The top, bottom and side edges can also be treated or painted for a more complete finish. Being laid flat means that finishes such as paints and varnishes are less likely to run and will level to give a nice even finish.
One potential downside of treating doors prior to hanging, especially if painted or varnished is that there is the risk of scuffs, scratches or chips in the finish when manoeuvring or fitting the doors if adequate care and precautions aren't taken.
Another consideration is where are the doors being finished? Being treated in a garden shed or garage may not be the best option as dust may stick to the finish. If the environment is damp or temperatures drop overnight, this can effect drying times and the finish.
With freshly sanded, solid doors, you can have a choice of any of the internal finishes we offer: wood wax, wood oil or solvent-based wood varnish/lacquer. All three will do the job but will look and feel very different:
With veneered or laminated doors, it's always best to double check with what the manufacturers recommend first before choosing your wood finish. This means you won't void any warranty offered or get any nasty surprises.
With veneered or laminated doors, it's always best to double check with what the manufacturer recommends before choosing a wood finish. This is so that any warranty isn't voided by using a product that is not suitable.
Fiddes Hard Wax Oil Natural is a good option that is designed to leave the wood looking and feeling natural whilst protecting doors from dirt and moisture. Oils are also very easy to apply and maintain. This product however has a high V.O.C content.
If the door manufacturer recommends a varnish instead of an oil, Manns Extra Tough Interior Varnish is a good option. As the name suggests, it's a very durable, water-based interior varnish that is perfect for interior doors. Unlike the oil, it will likely darken the wood slightly and enhance the natural colour and character of the timber but less than many other clear finishes. Being water-based, this product is classified as 'Low V.O.C'
To achieve a natural look and feel whilst protecting the wood, we recommend using Osmo WR Base Coat (4001) to help prevent mould and rot.
Once dry, use Osmo UV Protection Oil Extra which will nourish and protect the wood whilst slowing down the natural silvering / greying process caused by the suns UV rays. The oil dries to a durable, moisture repellent finish that is easy to maintain. Both the Osmo WR Base Coat (4001) and Clear UV protection Oil Extra 420 will darken the wood slightly giving a 'damp' like appearance. You can get an idea of how this will look by wiping the untreated wood with a damp cloth.
If you feel this is too dark, then you could have a look at the Osmo UV Protection Oil Natural 429 from the same range, this one has a minute amount of white pigment in to counter the darkening. To reduce / avoid the darkening that the Osmo WR Basecoat would create whilst preserving the door prior to oiling, use a suitable wax free wood preservative prior to applying the Osmo UV Protection Oil Extra.
Sample sachets of the Osmo oils are available and doing a test area is strongly recommended as the type, age and condition of the wood will influence the final finish. In other words, the same product applied to 5 pieces of different wood will likely give a different finish on each.
You could take a look at the Sadolin One Coat High Performance Woodstain. This product has a range of colours, including Rosewood, and is suitable for exterior doors, giving a semi gloss finish.
It is a highly durable and flexible woodstain, that is resistant to peeling, flaking and blistering and is washable. And as a one coat system makes the job a lot easier and quicker.
Horizontal surfaces are always the first to weather as they are typically more exposed to the elements, standing water and moisture ingress. Vertical surfaces tend to be less exposed and water just runs off.
The key to avoiding these issues is regular maintenance. To rectify this situation, use Methylated Spirits to remove dirt and grease from the exposed surface. Once cleaned, the exposed wood should be treated with a mould and mildew treatment such as Barrettine Mould and Mildew Cleaner to kill off any mould spores embedded in the grain of the timber. Once dry, treat the area with a wood restorer such as Osmo Wood Reviver Gel (6609) or Barrettine Wood Reviver to restore the original colour of the timber and then re-apply 2 coats of Osmo UV Protection Oil Extra.
An additional layer of protection that can be added prior to oiling is one-coat of Osmo Wood Protector (4006). This product is a highly water resistant base-coat, preserver.
An alternative to the above would be to sand the horizontal surfaces to remove the grey surface and then re-oil once new, fresh wood is exposed. We would however recommend that the wood is still treated with a mould and mildew cleaner prior to oiling to be sure that all mould spores have been eliminated.
The maintenance period for these products is always difficult to estimate as it is literally down to how much wind, rain and sun the wood gets. For example, the windows on a cliff top, sea facing cottage will require more maintenance than a sheltered town house.
We always recommend Manns Extra Tough Interior Varnish for internal veneered doors. It is a water-based clear varnish and is available in four sheen levels from Matt through to High Gloss.
Disclaimer: Whilst every attempt has been made to provide product information that is as accurate as possible, it's important to clarify that trees and the wood that they produce can be affected by many factors. For example, the same species of tree grown in the same wood, even in close proximity, will be affected by age along with the amount of sunlight and water they receive. Other naturally occurring biological and environmental factors will also influence the density and grain of the wood as well as the moisture and oil content of the timber. No two trees are the same, meaning each piece of wood has the potential to look and react differently to the same wood finish. For example, product adhesion, colour variations, absorption rates and sheen levels. It is for this reason that we always strongly recommend carrying out test areas before starting any project