What is linseed oil paint and why use it?
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Well, it is paint made primarily of linseed oil (squeezed from the seeds of flax) with a bit of colour thrown in and boiled. It disappeared about sixty years ago with the invention of synthetic paints generally known as alkyd resin paints, the base of which is still natural oils (linseed, sunflower, safflower, soya and even fish!) from which the fatty acids are extracted. And I still refer to them as oil paints, as I did in my youth. Alkyd resin paints have been on the wane for two decades as acrylic (plastic) paints have taken over as the most popular paint for woodwork. But new production processes can make alkyd resin into an emulsion, suspended in water. The oils are fighting back.You should use linseed oil paint because it is good for the planet. It is made from natural materials. Far less energy is expended to produce it than conventional paints and it is made without fossil fuels. Linseed oil paints scarcely contributes to global warming compared to conventional paints.
You should use linseed oil paint because it lasts longer than conventional exterior paints, easily lasting ten or fifteen years. Theoretically, it should last a generation. While it is more expensive to buy, it works out cheaper in the long run, especially if scaffolding is required.
I won't hide from you that linseed oil paints have drawbacks. They aren't as easy to use as conventional paints. The surface coating they produce, while longer lasting, isn't as tough (the elasticity is part of the key to its longevity), so they scratch a bit more easily. And they don't come in anything like the range of colours offered by a mixing system offered by most of the multinational paint corporations.
How do you use linseed oil paint?
When I say it isn't as easy to use as conventional paints, I mean it. The oil paint is thinner, and thus drips more. It has to be painted on very thinly or it wrinkles when dry. It needs more stirring than conventional paint because the pigments sink to the bottom. When the first coat goes on, it doesn't look anything like as good as you probably hoped it would. And when stored, it will form a skin faster than you ever expected. There will be tiny bumps in the gloss finish, largely due to pigments not being thoroughly "wetted", so you may wish to strain the paint first (a sieve is provided). Because of its imperfections and lack of toughness, we recommend the paint for exterior use only. Otherwise it's pretty straightforward.For more details on using our paint and recommendations for internal use, please go to our page on the subject.
Some background on linseed oil paint
Natural oils have quite different characteristics compared to the gloss alkyd resin (oil) paints you will be familiar with. Modern paints go on thick and the liquid they are dissolved in (their solvent), whether white spirit or water, evaporates leaving a thinner film. Natural oils go on thin and get thicker as they dry! There is little if any solvents, but as the oil oxidises, it captures oxygen from the air, thickening until solid. They last much longer once painted. You would think that that alone would make them highly desirable. But they dry slowly, are not so easy to use, and do not form such a hard surface and they quickly disappeared after WWII when chemistry found ways to make these oil paints quicker drying, easier to apply and harder, by modifying the fatty acids in the oil and making a synthetic resin.Long before natural oils stopped being the main base for paint mixtures, all manner of additives were used to improve the drying speed and the opacity of the colour. And a century ago, lead was the single most important. Primarily used to block out whatever was being painted so it didn't show through (increase the opacity of the paint), lead made paint last a very long time, it acted as a fungicide, and it increased drying speed. Today most linseed paint manufacturers trade on the environmentally friendly aspects of the paint (pure oil, natural pigments). However, faced with the same problems, other additives have replaced lead. Titanium dioxide is used to make white and is used in huge quantities to increase the opacity of paint (whether linseed oil or acrylic), where white lead used to be used. Metal driers were discovered to act as catalysts in the oxidation process over a century ago, and manganese and cobalt are still used today.
Ours is not the only linseed oil paint
The Swedish company, Allbäck makes linseed oil paint. It is sold in the UK under the name of Holkham Paint. It is almost pure linseed oil, with a tiny amount of metal driers added. The German company Aglaia sells a natural oil paint, which is a concoction of linseed and other plant oils and terpenes (natural solvents) and metal driers. Ours is somewhere in between these two in its formula. All are expensive. You'll struggle to talk your painter into using them. They are none of them quick drying.What is different about our paint?
Our paint has been heavily polymerised. That is to say, it has started the drying process before it reaches you. This also means that it will not penetrate bare wood as deeply (the molecules have started to form chains and are consequently much longer than they are in raw linseed oil). We therefore supply a pre-treatment oil almost at cost to accompany any paint you purchase, should you need it. We also add resin to our oil. For the moment, we simply use resin from pine trees, the sticky stuff that oozes from the tree that people often call sap (although technically that's incorrect). It adds a bit of hardness to the paint and it speeds up the drying process, slightly. And while drying, it makes the paint sticky. But that stickiness is good for adhesion, so our paint is better at sticking to a previously painted surface than pure linseed oil. Also, pine trees exude this resin when damaged. The role of resin is to seal the wound and prevent infections. It kills. It is a disinfectant. That's why so many cleaning products have that pine fresh smell.
Because of the thickness of our oil and resin, we add small quantities of natural solvent extracted from grapefruit and orange peel. It is used in small quantities (not more than 15% by weight and generally under 10%) and should pose no health hazard (some people seem to fear hydrocarbons as if they were lethal -- see our page on solvents for more information). Not to people at least, but certainly to mildew.
Death to mildew?
For those of you not familiar with linseed oil paint, this might seem an awfully strange heading to get such prominence. But the simple fact is, linseed oil is notorious for growing fungus. Especially during the first half year after application, before the oil has completely polymerised. If you search this phenomenon on the internet, you will find many strange claims and stranger people. The strangest are the fine artists who make their own oil paints and subject flax seed oil to all manner of secret traditional cleansing processes in an attempt to recreate the paints of the ancient masters. The goal is to create a paint (and thus painting) that will easily last a millenium, presumably because they believe their own daubs are worth it. You will also find the utterly ignorant who assume that all products based on linseed oil will encourage mildew and thus eschew alkyd resin varnishes in favour of hateful acrylics for fear of miniature mushrooms. The cruel irony is, of course, that you'll never find a mould growing inside a tin on the liquid surface of an alkyd resin varnish, but you will find it on acrylic varnishes that have been sitting about for many years. Ignorance may be bliss, but it is also stupid.The simple fact is: linseed oil is notorious for growing mould. Linseed oil is or has been used extensively in the world of log cabins. And log cabins tend, geographically, to be most common in cool areas of higher rainfall (north American west coast, Scotland, Estonia). Trawl the log cabin forums and you will find discussions about the curse of blackness forming on logs. While Allbäck/Holkham paints claim to have discovered a secret to defeating the dark fungal menace through their choice of especially good strains of flax, timber treated with their paint does sometimes come over all mouldy. Whatever the underlying problems the timber may have, whatever the local environmental situation, there is no escaping this: when mould grows on surfaces treated with linseed oil, the fungus is eating the oil.
Our paint dries more thoroughly and contains pine resin. Fungus may grow in the wood under our paint, but it won't grow on top of it.
And the pigments?
The colour we add — and it wouldn't be paint without colour — is natural whenever possible. Natural pigments mean natural colours (and lightfast). The black is just carbon, the red is natural iron oxide, in other words, rust. Some of the yellows and browns and reddish versions thereof come from clay (traditional sienna, burnt umber, raw ochre, etcetera).
This earthy range of colours is completely natural. Not so the blues and vivid red and most greens. But these inorganic, synthetic colours are created by applying energy efficient processes to various commonplace metals. Those monitoring the ecological credentials of paints commend the synthetic colours as more environmentally friendly (they often contain a high percentage of reused materials) than natural pigments, which often involve a great deal of energy in the course of mining.Where we score over our competitors is that we offer a colour mixing service. It isn't backed by a computer-driven Dulux mixing machine, more like me with a measuring spoon and a large, filthy notebook. It is not exact science, but the range of colours offered far exceeds the home brands in any diy centres.
However, mixing pigments to achieve a desired colour and even the physical use of pigments as a colour source are frought with problems. Please go to our page devoted entirely to colours to find out more.
When does the woodwork need repainting?
In Scotland, the conventional wisdom for architectural maintenance was that woodwork should be repainted with gloss "oil" paint every five years (not that many bother to). Conventional wisdom on linseed oil paint websites is that it lasts 15 years without further treatment. Moreover, it then only needs repainted with a coat of linseed oil, which costs very little. With our inclusion of wood oil, we are aiming for a quarter of a century, a lifespan quoted by some traditional Swedish builder/painters. But the success or failure of painted surfaces depends on many variables quite independent of the paint itself, primarily the surface taking the paint (raw wood, planed timber, and what type of wood at that and its ambient moisture content, old paint, linseed putty, silicone, and its exposure to sunlight). Like any other paint, linseed paints on north-east facing surfaces, out of the sun and rain, do better than paint on south-west facing surfaces (sorry for not taking you antipodeans into consideration here). Like any other paint, linseed paints tend to fail on timbers that get very wet and have an average moisture content well above 15%, as window sills often do. And like any other paint, linseed paint does better on rough, "off-saw" timber than on a planed, smooth surface. Indeed, the paint will do so much better that it is well worth specifying rough unplaned timber if you are building anew. This will add years and years onto the repainting cycle.Traditional gloss oil paints and modern acrylic paints both suffer structural disintegration primarily from a pounding from ultraviolet light. Linseed oil paint appears to suffer structural disintegration primarily from organic and inorganic decomposition. Because mould and pollution, which are in turn affected by moisture and local geography, play an even larger part in the long-term disintegration of linseed oil paint than ultraviolet light, it is harder to predict how long its life expectancy is in your specific situation.
So, is it worth it?
The paint is expensive. The painting programme will take longer and is more drawn out than usual. That makes the labour expensive too. But once on, there is little and only inexpensive maintenance for the next three or four decades. By that time, the "maintenance free" uPVC windows next door will probably have been ripped out, plastic or metal parts having failed and being impossible to maintain. So, yes, in the long term it is value for money. But it also offers things that can't be valued in monetary terms: a good environmental conscience, a sense of standing apart from the crowd, and an excellent talking point at your next dinner party.Who are we?
We are me, a cabinet maker cum architectural joiner based in Glasgow, with a PhD in archaeology. A love of the past and a passion for extending my range of unprofitable labour led me to try mixing my own linseed paints. To my wife's considerable surprise, the experiment was successful and the product looks financially viable. She'll be in charge soon.Ross Samson or Valerie Lyon
0141 632 8681 or 07985 046827
28 Riverside Road, Glasgow G43 2EF