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Used traditionally on timber for centuries before falling out of fashion, linseed paint is now having a resurgence as owners of historical buildings grapple with problems caused by the use of film-forming paints over the past 50 years and consumers search for more sustainable options for their homes. Michiel Brouns, owner of Brouns & Co, is reintroducing this all-natural product to the UK and US markets.
Michiel Brouns set up Brouns & Co around eight years ago, having moved to the UK from his homeland of the Netherlands where he worked for a company that surveyed historic buildings. “Timber rotting, walls disintegrating, we would analyse what the problem was and come up with solutions and products to remedy that. What we found, certainly for rotting timber, is that in pretty much all of the cases it was caused by plastic film-forming paint trapping moisture, which keeps timber wet because you can’t get the water out. That’s one of the things where linseed paint is completely different from a regular film-forming paint: linseed paint isn’t designed to keep moisture out. It does, but it’s not designed to do that. It’s about letting the moisture leak out, so the timber stays dry and doesn’t rot. That was my background.”
When asked by architects what he would recommend for historical buildings suffering from rotting wood, Michiel would recommend linseed paint – a completely natural product that was traditionally used for centuries to protect wooden structures such as buildings and ships. “I just got this blank look, even from preservation specialists, so I thought ‘this is crazy, let’s do something about this’, so I decided to reintroduce linseed paint to the British market.”
More commonly known in Europe, linseed paint is manufactured via a refreshingly simple process: “You start with flax seeds. We work with a farm close-by in Collingham in the UK that grows flax. We are only interested in the actual seed. This gets pressed and then cold-pressed and then from that you get raw linseed oil. That’s the initial step. It’s completely natural. The viscosity of this is too thin to grind pigments into and it dries very slowly, so we boil it and it changes colour and viscosity. It changes chemical structure. This is then good enough to grind pigments into. We use powder pigments, zinc white, carbon black, Prussian blue.
“The very traditional method is the same way the old masters used to mix their paint: a muller and a slab, which is essentially a glass plate with a grinder – obviously, you can’t do that to scale. So, we use triple roller mills, which gives the same result.
“There aren’t too many ingredients. Also, we use powder pigments rather than colourants. Powder pigments really have an important part to play in resisting UV. That’s why it needs to be a solid pigment: the combination of the oil and the pigments together gives you all the protection you need. That’s essentially, in very simple terms, how you make it.”
Falling out of fashion
Linseed paint has been around for centuries, if not millennia – its use has been traced back to the ancient Egyptians. It’s sustainability credentials only add to its reputation as a natural way of protecting substrates. So, how did people just forget about this sustainable, natural way of protecting their buildings?
“There’s a very clear marker and that’s the Second World War. At the end of the war, there was a completely new mindset about ‘everything modern is the future’. We saw a much higher use of concrete, big structural glazing, lots of steel – and plastics. Synthetic paints appeared in the 1930s and 1940s, but there was no scale to it. Alongside this, there was an enormous waste mountain of acrylics and latex readily available, which was a by-product of the war effort. Then, for the next 30 years nothing else but synthetic paint was used.
You see all these problems occurring with historic buildings that never had an issue for centuries. They had survived that long and then, all of a sudden, in the last 50 years they began to experience problems because they were being treated with synthetic paints.”
Linseed oil is closely associated with historic, timber buildings but it is just as relevant for modern buildings and for a range of substrates.
“Linseed paint works really well on metal, for example. It has the most amazing anti-rust properties because the surface tension is lower than water, so water can’t even get in and you don’t get rust. It’s not rocket science, we just need to tell people about it.
“The problem is, nowadays we live in a society where, for building products and timber for exteriors, it’s ingrained into the whole industry and even DIY professionals that you need wood protection, in the form of chemical treatments and that is just not true. The plastic paint industry is so big, with multi million pound turnovers – they have big marketing budgets and there’s been no voice against that for the last 30 or 40 years. What we need is people who do new-builds as well to start to realise that linseed oil has worked well for hundreds of years and should also be used on modern structures.”
A sustainable option
Given the phenomenal increase in the importance of sustainability over the last few years, perhaps that will be what returns linseed paint to the forefront of wood protection?
Linseed paint has no VOC emissions, or only trace elements, and it protects against all weathers. Once it has been painted, wood won’t rot and iron won’t rust. It has fantastic wicking properties, enabling the evaporation of moisture instead of trapping it under an impermeable film. It’s a subject that is obviously close to Michiel’s heart:
“Four years ago our website was all about using the paint on historic buildings and the sustainability aspect was down at the bottom somewhere – people were just not interested. Now, it’s the first thing on the website because the dialogue has shifted completely. It doesn’t matter whether it’s an historic or modern building – linseed paint is suitable for everything. And not just purely from a sustainability point: it’s healthier. For the building, for the people using it, such as the decorators, for the people living in the buildings… it touches all those areas.”
It seems that whilst most of the world forgot about linseed paint, northern Europe held on to this traditional product: “Scandinavia never really switched off from it. If you go anywhere in Scandinavia they will know linseed paint, they will have used it, they never stopped making it. It’s the same in Germany and the Netherlands – so the UK is behind the curve on that but is now very quickly catching up and rediscovering all these traditional building materials.”
On his mission to bring linseed paint back to the UK, Michiel has worked with heritage buildings such as Chatsworth House and the Grosvenor Estate, with interest now also coming from the USA in the form of the National Park Services, which maintains several historic buildings. “We are getting an increased demand from the US. New England is our biggest market and a little bit south from there – the original 13 colonies. A lot of their timber houses date from late 1600s, early 1700s onwards with a big section from the 1800s. A lot of them followed the Scandinavian way of building properties. We’re used to building with stone in the UK, whereas Scandinavia built a lot more with timber and timber cladding on the outside. When they have been painted [with petrochemical paint], essentially what they’ve done is put the house in a big Tupperware box, because that’s non-breathable. It was to try to keep moisture out but the problem is, with UV light and the elements, water will get in and then it just sits there.”
The aim is clearly to increase the use of linseed paint in the UK, a mission that Brouns & Co is achieving. Following a spike in demand during lockdown, the company invested in increased production capacity and is now ready to cope with up to 10 times the current demand. But would scaling up production affect the product’s sustainability credentials at all?
“No, because it’s still the same ingredients, the same method, and what’s important as well is flax is not a mono-culture crop. It’s a really healthy crop to grow.
“The flax plant is one of the most versatile plants. Linen is made from flax and you can use the whole plant. It’s not like all the yellow rapeseed fields that you see. They only use the seed and the rest of the plant is discarded. With the flax plant, you can use the plant itself for the linen industry and even with grinding the seeds to make the oil, the shell that is left can be pressed into cakes and made into animal feed, so the whole plant is used.”
So far, I’m converted. Linseed paint is natural, sustainable and has a proven track-record of protecting wooden structures – in Scandinavia, original coats of linseed paint have survived on houses that are several centuries old. Compare this to the sudden influx of historical buildings that are now experiencing rot or damp issues after a 50-year period of using petrochemical-based paints and it seems like a no-brainer. But are there any cons to this paint product?
“Yes, like with any product there are pros and cons. We live in a society where everyone wants everything now. Everything is instant. We are so used to working with paints that are full of VOCs and drying agents, so a coat will dry in two or three hours. With linseed paint, you can’t do this because there are no VOCs. There is nothing to accelerate the drying in that process, it’s purely dependent on exposure to UV light and oxygen. Therefore, a coat will take about one to two days to dry. A project might take two weeks rather than two days, but then the benefits coming from that are big: with linseed paint, you never have to sand it down or scrub it off to remove it. It goes matte over time, but when that happens you just need to wipe over it again with some linseed oil. So the longer drying period is completely offset by the long-term benefits.”
And what does the future hold for linseed paint – will it return to the forefront and overtake, as Michiel calls it, ‘plastic paint’?
“I hope so. I’m very concerned about greenwashing and I think the big paint manufacturers will come up with a way of branding their existing paints as environmentally friendly, which is already happening. They’re all calling their paint water-based. There’s no such thing as water-based paint. All it means is that you thin it with water but there are still plastics – latex acrylics, emulsifiers, synthetic pigments – but then they add water to it to mix it. I would like to think that the big manufacturers have to switch over and make something really sustainable, but I don’t think there’s a track record to prove that it’s going to happen.”
Perhaps if more consumers knew about it, it would be more popular?
“That’s important – that will drive the genuine change. If people demand it, then it will happen. People need to realise that there is an alternative and ask for it. And ask questions –What are the ingredients? How is it made? What is in it?”
Over the last 15 years, Michiel Brouns has been researching the production methods and literature around linseed oil and paint. He has now written his own book, which delves into the history, production methods and how the paint works. It will be published in June and can be pre-ordered here: https://linseedpaint.com/book-linseed-paint-and-oil/