Stand oils (thick oils) or oil cookings are produced by heating native oils such as linseed oil, tung oil (also: china wood oil), castor oil and other oils (soybean / safflower). Contrary to blown oils, this takes place under exclusion of oxygen.
In combination with other oils, binders and resins, such as alkyd resins and hard resins, these stand oils can be used for the formulation of lacquers, e.g. wood lacquers, glazes and wood oil systems.
Compared to native oils, stand oils have faster oxidative drying properties and show higher hardening as well as stability for example against water. The higher water resistance can be further improved by cooking with an alkyd resin or hard resin, such as phenolic resin, resin ester or resinate. Those systems with hard resins are known as so-called hard oils
Common stand oil qualities are e.g. linseed stand oil 2-3 P (200-300 mPas), 45 P (4500 mPas), 90 P 9000 mPas), 450 P (45000 mPas); tung stand oil / chinese wood oil 30 P (300 mPas), 90 P (9000 mPas); castor stand oil (50 P (5000 mPas), 90 P (9000 mPas).
P means Poise, mPas means milipascal-seconds.