Is it wise to remove the rivets of the frame in order to be able to reach to every sq. inch of the metal with sandblast? See pics with rivets on cross member. Also, notice the crack. It would be easier to fix it if rivets are removed. Can this be done and assembled back with bolts? Will it have the same strength as rivets. If so, which should be a proper torque setting for bolts and what grade? Thanks for the help. Frame crack and rivets