Please indicate typical properties of alkyd varnishes. Properties of alkyd varnishes, especially flexibility, resistance to weather conditions, for scratches, Yellowing and heat resistance are oil dependent, and therefore the type and amount of fatty acids. On the whole, these varnishes are sufficiently resistant to all the usual effects. Because alkyd varnishes are easy to use and are characterized by beautiful flow and good adhesion, are still one of the most commonly used painting materials. They are saponified by the lyes and can therefore be removed with etching agents.
What high temperature resistance do alkyd varnishes have??
Most alkyd varnishes have a temperature resistance of up to 393 K (120°C). Some radiator varnishes can even withstand temperatures up to 453 K (180°C). Despite this property of the binder, most alkyd varnishes turn yellow (also those for radiators) already at a temperature above 353 K (80°C). It is caused by the oil in the alkyd resin, especially linolenic acid, being a component of oils.
What solvents and thinners should be used for alkyd varnishes?
White spirit is best suited as a solvent and thinner for alkyd varnishes (in trade, it also occurs as the so-called. turpentine replacement). In principle, however, the solvents recommended by the varnish manufacturer should be used. These so-called. synthetic resin thinners consist of a mixture of various solvents and should guarantee the stability of maintaining the beneficial properties of varnishes and paints also after dilution. Spray thinners generally contain more volatile solvents than brushable thinners..
For what substrates are alkyd varnishes and paints suitable?
Alkyd varnishes and paints are suitable, depending on oil content, for wooden substrates, most metal substrates, for inert plasters and various plastics. The substances contained in various types of wood, however, may delay or even prevent the curing of varnishes and alkyd paints. Such varnishes and paints are not suitable for zinc substrates, in this case there is a chemical reaction with the zinc, ultimately leading to chipping of the coating. On alkaline plasters, alkyd varnishes and paints are saponified and become water-soluble. Their adhesion to plastics is very diversified, depending on the type of plastic. In this case, particular attention should be paid to the manufacturer's recommendations.