paint too thin?

yeah i have a urethane single stage paint that i love the color of and it looks good. the only problem is that it is really thin and its hard for me being a novice not to get runs everywhere. the paint is 3-1-1 paint, hardener,reducer. i was wondering if it would be safe to use a little less reducer to not make it so thin? isnt that all reducer does is make it thin enough to spray? thanks,

im sorry i thought this was paint and bodywork can a mod please delete this please. sorry

the reducer is also part of what makes the paint "go off" (the last 2 numbers are in relation with the air temp) But yes you can add a little less.. how ever getting the correct reducer for the temp you are spraying in would be the better bet.  then its all about technique.  spray a tack coat first..  just enough to get like about 1/2 coverage..  this will look a little orange peal-ish ....no problem. when that paint is tacky, but not wet (put your finger in the paint -- on some TAPE not on your truck!!) and if there is spiderwebs hanging from your finger.. its ready for second coat.  spray the 2nd coat kinda wet, but you will still see overlapping passes, and voids, thats o.k. dont get it too wet.... do the same for the second coat (the spider web thing) but let it set up another 15/ 20 min after that, then put on your 3rd coat.. this one should be as uniform as possible, filling in any voids and be a finished product that you like the look of.  look around for any last "shy" spots and hit them before the rest of the paint starts to dry.  GOOD LUCK!