clear coat recommendations

I painted my grill (over the chrome) with krylon fusion, it doesnt but me that its matte but it does bug me that it chips really easy. is there a good clear coat i could use to help it from chipping?
When i first did it it looked like crap (didnt sand the stubs all the way down to stotashi(sp?) it) so i had to respray it and when i did there were big areas bubbling up from the previous time. how can i avoid this?

 

Did you respray with the same paint? If not, different brands of paint can react with each other, with the new one dissolving and lifting the old layer, that's what your "bubbles" sound like. I don't know how much you're looking to spend, but the toughest clear coat I know is something called Spraymax 2K. It's about $20 for a can though, and you need a good respirator (not one of those cheap paper filter types) to use it as it's a ureathane-type. If you lifted the paint, it sounds to me like you should probably start from scratch, sand off the paint and then buy all the same brand color and clear. Spray the whole thing in a day, with lots of light coats a few minutes apart. After you've got the color coat on, and put a few layers of clear on it, spray one or 2 more medium coats of clear and let it cure for a week before putting it back on.