My blaster guy mixes a blend of walnut shells, glass beads and plastic media for doing whole cars, works quite well and he avoids the large flat surfaces so they don't get wavy from the peening and heat. Tim

1941 Taylorcraft
1968 Charger
1994 Wrangler
1998 Wrangler
2008 Kia Rio
2017 Jetta

I didn't do 4 years and 9 months of Graduate School to be called Mister!