Sandy,
If the block is old and rusty, I cannot imagine a hot tank getting it as clean as an oven / shot blast system does. We have had a oven and shot blaster since 1988 an I cannot imagine cleaning old cast iron parts any other way. They turn out looking like new catings. You do have to be very thorough in getting the shot out. Our system has a big rubber lined drum that you tumble the blocks or heads in after they come out of the blaster. It bounces them around pretty good and we have never had a problem with shot retention. We also run every thing through our spray washer after machining so that helps too. I only tried running aluminum one time and was not real happy with the way the blaster beat up the castings, so we still spray wash and glass bead aluminum.
If the block is old and rusty, I cannot imagine a hot tank getting it as clean as an oven / shot blast system does. We have had a oven and shot blaster since 1988 an I cannot imagine cleaning old cast iron parts any other way. They turn out looking like new catings. You do have to be very thorough in getting the shot out. Our system has a big rubber lined drum that you tumble the blocks or heads in after they come out of the blaster. It bounces them around pretty good and we have never had a problem with shot retention. We also run every thing through our spray washer after machining so that helps too. I only tried running aluminum one time and was not real happy with the way the blaster beat up the castings, so we still spray wash and glass bead aluminum.
