This section is from the book "Cyclopedia Of Painting", by George D. Armstrong. Also available from Amazon: Cyclopedia of Painting.
The priming coat for zinc should be as directed for flat work. Lead is best to use for priming or first coat over a sized surface. Where two or three coats of flat zinc work are specified, reduce zinc that has been ground in varnish with turpentine to a medium thin consistency and apply over a first coat of lead. When dry, rub with curled hair and apply a second coat of the same mixture of a heavier consistency. This will dry flat and make a beautiful finish.
If a gloss finish is desired, apply the finishing coat of zinc in varnish reduced with turpentine to a consistency of cream. To one part of this mixture add two parts white enamel varnish. If a higher finish is desired rub this coat with fine steel wool and apply a coat of clear varnish. This can be rubbed to the desired effect.
 
Continue to: