Drying oil is a film-forming composition made on the basis of natural vegetable oil – linseed, sunflower, soy. In addition, the drying oil contains a desiccant – a substance that accelerates drying.
Drying oil is used in the manufacture of oil paints and putties, as well as for the impregnation of wooden surfaces in order to protect them from decay. In addition, it allows you to reduce the consumption of paint and varnish during painting work: experts advise using drying oil as a preliminary coating – first apply two or three layers of drying oil on the wood, and then cover it with oil paint or varnish.
At one time, drying oil was considered almost the only protective agent for wood and a way to fight woody parasites. Now a lot of new and much more effective formulations have appeared, so the drying oil has somewhat surrendered its positions. However, she still has many fans..
Types of drying oil
Today, there are three options for drying oil: natural, oxol and composite.
Natural drying oil (GOST 7931-76) 97% 25 consists of natural vegetable oil (most often flaxseed, less often sunflower), the remaining 3% 25 is a desiccant (a substance that promotes rapid drying). Natural drying oil is used for diluting thickly grated paints and for impregnating wooden surfaces indoors. Experts do not recommend using drying oil for outdoor work – it is expensive and impractical.
Oksol (GOST 190-78. Grade “B” – drying oils, grade “PV” – semi-drying oils) contains 55% 25 flaxseed or sunflower oil, 40% 25 white spirit (solvent), 5% 25 desiccant. It is cheaper than natural drying oil. But both of them protect wood from parasites equally unreliable. And if you do not apply an additional layer of varnish or oil paint on top, drying oil – both natural and oxol – will have to be updated frequently.
Oxol based on linseed oil is considered the best, because after drying it forms a hard, waterproof and elastic film and does not turn black for a long time. Oxol is intended mainly for processing wooden and plastered surfaces indoors. Applied to the plastered surface, oxol improves the adhesion of oil, alkyd, dispersion paints and putties. Oxol can also be used for outdoor work, but it should be remembered that this material serves only for temporary preservation of the surface, so it must be painted with paint, varnish or enamel.
If you need a cheaper oxol, you can buy its “sunflower” version, which can be used when processing wooden and plastered surfaces indoors, and outside you can only process those surfaces that are under a canopy or roof to protect against water ingress, and even better – paint over with a layer of oil paint so that the wood does not start to rot.
The cheapest and most smelly composite drying oils, they do not have a GOST number that would strictly regulate their composition, but they are produced according to technical conditions (TU). The composition of the combined drying oils includes chemical components that replace natural resins, petroleum resins and other by-products of petrochemicals. It is better not to use composite drying oils for treating wall surfaces either in the apartment or on the balcony. They are toxic and harmful, and even dry, they continue to smell for several years..
Tips for choosing
When buying composite drying oils, be careful!
If the drying oil is based on fuz (sediment of natural vegetable oils), such drying oil will never dry out, and neither varnish nor paint will be able to paint over this mess. Fusa-based drying oil has a reddish color and a dark sediment.
If you treat the surface with linseed oil made on the basis of osprey (a substance consisting of petroleum-polymer resins), then it will either never dry out, or will begin to crumble. This drying oil is the thinnest, lightest and cheapest of all existing varieties..
When choosing and buying drying oil, you should: