Seedy, Sandy or Specky Varnish

¶ Seedy, Sandy or Specky Varnish. This defect looks like a surface over which some fine sand or other gritty substance had been sprinkled while the varnish is wet. These particles will not be in evidence at first but after the coating has been drying from half to one and one-half hours the seedy effect appears.

¶ As to the cause of this trouble. Look first at the varnish used. Varnish which has been recently made, has not aged enough and is not ripe may dry with a seedy surface.

¶ Allowing varnish to become chilled in winter is one cause of the appearance of a sandy finish of varnish. After varnish has been brushed on, if the surface becomes chilled, it may become covered with a multitude of tiny specks and when the coating is dry the specks are even more in evidence. The cause is the chilling1 of the oil and the reaction of the driers. The remedy is, of course, the proper heating of the room and the varnish to 70 or 80 degrees. The seedy, or sandy particles are congealed bits of gum resins or oils or driers. Crystalized particles of drier are usually the cause.

¶ When varnishes are exposed to zero temperatures or nearly so during transportation from factory to finisher the sandy, seedy surface may appear when the varnish is spread. Such varnish should be warmed thoroughly before being used. Place the varnish can in a pail of hot water for half an hour or more. About 110 degrees is the correct temperature of the water for this purpose.

¶ Age does not cause varnish to become sandy or seedy, but with age, when the can has stood around for years, varnish will deposit some settlings in the bottom of the can. For that reason a careful finisher will never use the varnish from the bottom of old cans without first straining it. As a rule the last quarter inch in the bottom of any can, old or new, will not be used for finishing by a careful man. Such varnish is set aside for rough work.

¶ When varnish is allowed to stand around uncorked it will skin over the top and when this skin is broken it is sure to become mixed with the clear varnish and a seedy or specky surface will result, unless the varnish is strained before using.

¶ Pumice stone or other grit, like that from sandpaper or steel wool, on the surface will give the specky, seedy appearance to the finished varnish coating. Dust from ceilings or other surfaces which cast it off into the air will give the seedy appearance to varnish. Likewise the use of brushes which are full of dust or the dried varnish or paint skins from previous work will cause the gritty, sandy, seedy finish on varnish.

Next Page: Pitting, Pin-holing, Pocking and Blotching.