Advice on painting

Hi. Looking at the custom made rings I put together for last Teonn, I notice the paint job flecks off them rather easily.

Partly, I reckon this is because they are water based paints, and onto a metal surface. Question is, would there be a clear film that would seal these paints to prevent flecking?

So, you want to permanently colour a metal? What metal? What colour?

You could try applying a coat of polyurethane.
However the problem painting metal is the bond between the paint and the metal. Paint is only as good as the bond to the substrate. For metal there are particular metal primers designed specifically to stick to metal. Or I noticed the other day that some roof paints are labelled “no primer”.
This is all from a architectural background, someone may offer advice on models, which may be more your scale.

Make sure you base coat before applying then try this as a sealer. Also if the metal is shiny give it a quick sand this will help the paint bond to it.

http://www.slavetopainting.co.nz/products/anti-shine-matt-varnish