This video shows mixing and applying thinned lacquer to a very narrow, masked off scar.  I mixed good turpentine into lacquer with a palette knife and then applied it with a brush.  I have the area masked so when I get to the later stages my cleanup is less and to lower the chance of scratching the surface.

For more on traditional, lacquer based kintsugi see kintugi.com or https://www.kintugi.com/?page_id=225