Can linseed oil paint on old coatings, such as acrylic, emulsion paints or alkyd paints apply?
Yes and no. Linseed oil paint can adhere to these products, when they are primed, thoroughly cleaned of possible fatty surfaces and residue.
If you want to achieve good saturation and excellent adhesion of linseed oil colours on and beneath wood surfaces, the only way to do this effectively is to completely remove any old coats of paint.
A simpler and more feasible alternative would be to remove the loose paint layers with a paint scraper, to thoroughly grind or sand the surface and then to use linseed oil as a primer or bond to ensure a “solid surface before painting with linseed oil paints”. Perhaps you may be lucky enough to notice that the old primer or paint has been well kept. If the paint should brittle, lump or crmb, simply remove that layer and repeat the scraping process until it has all been removed. Now you may prime it with linseed oil and after it has dried completely, you may paint it with linseed oil paint.
Why not "dry" the linseed oil paint?
Probably one or more of the below mentioned problems occurred:
1. The linseed oil paint has been applied on too thick. If a "puddle" of colour appears on the surface this layer will form a film on the surface. The necessary oxygen cannot penetrate through the linseed oil paint and prevents it from drying or slowly drying below the film. Should this be the case, the entire coat must be removed before applying a thin new layer.
2. The linseed oil paint layer has not received enough UV sunlight, probably because the object has been painted in a dark room or at a workshop. Place the object into daylight. If that is not possible, an ultra- violet lamp should be used to irradiate the object for at least a few hours. This will ensure the linseed oil to be completely dry and hardened.
3. The proportion of pigment in the paint is too high and hems the curing process. In such a case, you must be patient.
4. The linseed oil in the colour still contains hardening hemming mucilage or film from pressing, which have not yet been removed.
5. The object is located in a climate with high humidity, very low temperature, or "congested" air. Physical conditions, which reduce the speed of the chemical curing process. Too high humidity can additionally result in mold being formed on the linseed oi before it has been completely cured.
Normally, linseed oil paint should be “bone dry” after a minimum of 2 days, depending on the situation information described in the previous question circumstances. The paint layer is not fully cured or dried within 7-8 days.
The curing process may be reduced to 10-12 hours with the aid of desiccants. Desiccants are different substances such as Cobalt, manganese, or iron, which improve the absorption of oxygen in the oil. The colour is characterized, however, slightly brittle and less supple or smooth.
The linseed oil paint is wrinkled. What happened?
The linseed oil paint was applied too thick and too short intervals. The colour could not be properly cured or dried between coats.
The white linseed oil paint is yellowing, what can you do?
White linseed oil paint is always yellows in dark rooms and when exposed to light they begin "fading". The most obvious can be observed on the windowsills under flowerpots where dark yellowish spots have formed. If you remove the flowerpots, the dark spots disappear after a short time under the influence of light and at its own accord. The slightly yellow tone can be reduced by simply adding a pinch of Paris blue pigment or burnt Umber to the white colour.
Should you use cold-pressed linseed oil or linseed oil varnish for mixing a linseed oil paint?
One can use both. Traditionally, linseed oil paints were prepared with boiled linseed oil, because the colour is more robust and shiny and hardens quickly. Linseed oil paint mixed with cold pressed linseed oil is slightly porous, less shiny and slow curing. These properties are better suited for exterior wood.
Is linseed oil paint a wood protection paint?
Linseed oil paint cannot compare to a wood preservative. Wood protection paints have very different properties and are also applied differently. With "wood protection" it is typically referred to a chemical wood preservative, which is a thin impregnating liquid. It will often contain paraffin or turpentine. An anti-fungal toxin is usually added. It may even contain alkyd resins and dye.
Should you decide to use such a wood preservative, please be aware that the volatile constituents dissolve out of the wood, the water-repellency of the natural oils in the wood will be driven from the wood structure and sustainably weaken the wood over time.
Apart from that, the fungus and mold-inhibiting toxins (fungicides) cannot penetrate the wood and actually have no protective effect in the long run at all.
Linseed oil, in comparison, contains no solvents or anti-fungal toxins and therefore cannot be compared with wood preservatives. Please remember that flax oil can compensate for the loss of natural oils by the use of preservatives which contain turpentine.
One should never use water-soluble salts, for example, Zinc Sulfate, to mix in linseed oil colours to make them anti-fungal.
Is linseed oil paint environmentally friendly?
Absolute! Linseed oil is 100% all-natural product, it is 100% degradable, non-toxic and is also perfectly suited for the areas it was designed.
With regard to the linseed oil paint, and the overall environmental performance depends mainly on the ingredients. For example, the pigments, desiccants and any solvents. Preservatives are completely unnecessary here.
Desiccants (drying agents) are not necessary. Absolutely no solvents. We do not use any solvents in our colour. Therefore, we s do not to equate these factors at all when considering the environmental safety of our product.
As for the pigments, they are completely identical to the pigments that are used in other colours. This point could actually deem all colours.
Recent studies have shown linseed oil and linseed oil colours with their natural curing process set off a number of volatile organic compounds. The process is completed after 7 days. When paint, please be sure to allow enough fresh air to circulate. The same elimination process of volatile organic substances is actually a natural process. It can be commonly found in other oxidizing products such as vegetable oils like Olive and soya bean oil which we generally consume.