It is essential that a varnish be used which will mix perfectly with oil and benzine at a temperature of 60° F.
Varnish colours are best thinned with turpentine, but owing to the high price of turpentine the large factories insist on using benzine or some of the turpentine substitutes now on the market.
The fact that some of the turpentine substitutes work better and give a better "flow" with the paint and varnish, is due to the fact that most of them contain a heavy distillate of petroleum similar to kerosene.
Kerosene oil has the double property of thinning and imparting "flow" to either paint or varnish, but retards the drying, hence too much must not be used.
Damar varnish, which will not stand thinning with benzine without separation of the gum or becoming cloudy, will permit of dilution with kerosene to quite an extent.
So far as durability is concerned, kerosene imparts more durability and is more waterproof than any of the other thinners. Combined with rosin and manganese oxide, it may be made to dry like raw linseed oil, but, of course, does not possess the same properties.
In dipping paints, as in all other kinds of paints, good judgment must be used in the mixing, and it is absolutely essential that paints for soft wood, or other absorbent material, contain enough oil, or binder, to hold the pigment.
White Paste Primer. Extra Fine.
- 300 lbs. white lead (carbonate).
- 150 " zinc oxide.
- 50 " floated silica.
- Grind in 10 gal. raw linseed oil.
- Product = 575 lbs.
This paste is thinned with turpentine or benzine for dipping purposes in the following manner:—