1/4"?!? i wouldent go over 1/8" thick, and if you have to keep it to a minimum..rage is very good along with topcoat lightweight body filler, the only bondo brand i buy is their professional(gold?) stuff and it doesn't compare to topcoat or rage..if you only need a quart or two why not spend the extra 5 bucks and be happier? bondo doesn't like to stick to paint either