I work for a company that builds store fixtures for high end retailers. Our latest project requires us to weld brass. The problem I'm having is, I'm getting a 1/4" to 1/2" crack in my weld where I start. The material is 1" thick brass square bar, and I'm putting a 1/8" deep bevel on my weld joints. I'm using a Dynasty 350, DC current, and silicon bronze rod. The welds are actually turning out pretty nice and not all the welds are cracking. Any suggestions would be appreciated.