*** Normally no primer is needed as the plastic surface lends itself well to any buffing process,just make sure that there is no grease on the surface by giving a quick wipe with a lint free cloth and a tiny amount of surgical spirit,spray on the first coat of buffing material and allow to dry for at least 48 hours,next attempt the buffing process working a small area at a time,different areas of metal panelling such as the die-electric ones on aircraft can be simulated by laying a draughtsmans foil mask along the panel line,buff straight up to this simulating the riveted panels on aircraft structures,normally one good coat should be sufficent and there is a danger if further coats are added that the build up will not polish up as well.As always use a slave subject such as an old model to experiment with first,learn from this what your own and the materials limitations are.Some materials slightly etch themselves into the plastic,dont worry this is all part of the process and the first buff will soon evolve into a shiny surface.Dont forget to look into the products sold for embellishing picture frames,they make some good alternatives to model finishes and are much cheaper.
*** Go easy with the masking,best thing to do if you use masking tape is to draw it through your fingers,this reduces the tackiness and stops that vicious pull on the metallic finish,yes use the gloss black in preference to primer,the gloss must work better for some reason.
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