If you are getting alot of pinholes you are not mixing the filler well enough or kicking it too hot. The filler should have an even color hue to it all the way through and mix it colder then it should be. This will give you a little extra time to finese it. Rage is proably the best filler available. I have yet to use anything comparable. Also body filler will not fill small pinholes nor would resin. You need a pinhole filler material like Icing...as mentioned above.