I have bin melting large electrical motor end bells Bearing housings and have had solid castings most of the time now lol I started to use the fan shroud no as we have a few in the scrap ....20lb. To80lb brakes easer the the end bells on average the are only 3/8 thick real nice pours like hot buttter on toast I have bin I have still added ferosilicon at 800 to one do I need to ? Thanks Todd
How old is the scrap iron that you are melting? Castings made from pig iron may not need ferrosilicon but castings made from recarburized steel to cast iron level will always need ferrosilicon. End bells are a very soft fluid iron to pour.
I melted a bath tub that was made in 1970 and was some of the best iron I have melted. If you are getting great results with that ferrosilicon addition I would not change it.