The Enamel surface needs to be older than 6 months.
Test a small area to see if sanding would be needed in conjunction with the cleaning.
a small area with Lacquer thinners – wait 20 minutes and paint your
first coat – allow to dry and then paint your second coat.
Wait for 24 hrs and then test by scratching the surface.
the paint is removed by scratching we advise that you sand first and
then clean with Lacquer thinners – this will make sure that the paint
will grip onto the surface. Once you have painted x2 layers and waited
24 hrs – repeat the scratch test again. If the paint continues to be
scratched off, a universal undercoat would then be need to be applied.
It is not uncommon for many enamel surfaces to pose a problem when painting on top of them.
Sand with 100grit sandpaper.
Clean well with Lacquer thinners and then start painting.
Larger surfaces need to be tested before painting starts. ( As above)