Hello John,
Maybe I’m at cross purposes with others regarding the terminology. I comprehended the discussion as Single Stage being that it was a two pack (using a catalyst) (2K) system, but the colour and gloss is with the paint being applied, with no other subsequent product application required, hence the term “Single Stage”; we call that paint system “Direct Gloss”. Some paint manufacturers have the letters “DG” as part of the paint specification, which stands for Direct Gloss. In this system, whatever paint that’s been prepared and not used, will be discarded as it contains a setting catalyst.
What I comprehended from this Thread is that a Two Stage system was referring to Clear over Base, which uses a Base Coat, that is the colour and is a 1K product that doesn’t use a catalyst, followed by a Clear Coat that uses a catalyst, over the coloured Base Coat. The Base Coat, off the gun, has a rather Semi Gloss appearance, very reminiscent to that of the old Acrylic Lacquer paint systems that were the cutting edge back in the late 60’s. Any left over Base Coat can be saved, whilst any left over, prepared Clear Coat will have to be discarded due to it containing a setting catalyst.
With regards to the degree of ease in doing a small paint repair as you have described, I don’s see much difference between Clear over Base and what I call Direct Gloss, both using a 2K top coat; in each case, you would end up painting the whole door. It could be argued that the colour matching with the Clear over Base may be a little more forgiving, for all but one adjacent panel, as the Base Coat can be edged out from the main repair area, then buried in clear. The colour of the original paint will be seen through the clear at the adjacent panel shut lines.
With the 2K, Direct Gloss systems, where its typical to paint the whole panel, the colour match has to be right. You can blend the edge of the Direct Gloss, 2K system, out from the repair area, but its more difficult in not getting a feather edge at the extreme edge of the paint repair.
With the repair of a 1K paint system, which functions more like an Acrylic Lacquer paint system, the surface of the original substrate will melt with the application of reducer. This allows for the edges of the main paint repair area to be blown out onto a wider area around the repair and melt into the original substrate; thus avoiding an obvious edge to the repair. Any left over paint from a 1K paint system can be saved.
So, in order of ease of pint repair of the damage you described, if the original system was a 1K product, then the 1K system wins hands down. If the original paint system is a 2K system (paint using a catalyst), then it’s line ball as to which of Clear over Base, or Direct Gloss is easiest in a small repair scenario.
Regards,
Bill
