Preparing the Surface
The preliminary stages of the work preparatory to enamelling are the same (except for the last two coats) as for a paint and varnish job.
Wherever there is old paint present which is cracked, crazed or soft, that paint will require removal. In this, as in other matters, it is always a false economy to build on unstable foundations. The processes of removal are fully described in Chapter Seven, to which the reader is referred.
The old paint having been removed, the surface must then be smoothed, knotted and primed with white-lead paint, also as described in Chapter Seven. This priming, when thoroughly hard, should be well sandpapered to render it perfectly smooth.
Enamelling over Old Paint
Then a thorough smoothing of the surface with waterproof sandpaper, which is moistened with a sponge, should be carried out. The sludge so created should then be swilled off with clean water and the work be left to dry.
From this stage onward, the processes are the same whether the old paint has been removed and a coat of priming has been applied, or the old paint has been merely washed and rubbed down.
Further treatment will consist of two coats of undercoating and one coat of finishing enamel. Nothing less will produce a perfect job of enamelling, and, where a very great change of colour from dark to light (such as black to white) is required, three coats of undercoating may be necessary to get that