Making the mould is a very easy process but the tricky part is getting all the aluminum to fill the mould cavity. The bell pattern is about 3mm thick and as I thought it didn't fill properly the first pour.Aluminum bell casting video:
The second pour I carved some of the sand off the cope part of the mould. This time the sand mould was filled properly. I like the contrast between the aluminum silver shine and the brass. Now I plan to make a back mounting plate for both of the bells.