Hammered Spray Paint

Hi all,
I paint a guitar effect with spray paint hammered. The first two layers where really sad, but the next two gave it that cool look cracked, but some parts did not have that look. Recently I re-applied paint hammered him and he is dark, and no cracking. How do you think of using this substance to get the crack!

Thank you in advance

The hammered effect is supposed to look like you dented the finish with a ball peen hammer, hundreds of small dimples, not cracked. It seems you might have used two types of paints or primers that are not compatible with each other (oil-based paints to water based) or something like that. This sometimes causes the crackling effect. Good Luck